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Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2018	Mar. 28, 2019	Jun. 30, 2018
Document And Entity Information
Entity Registrant Name	Celsion CORP
Entity Central Index Key	0000749647
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity a Well-known Seasoned Issuer	No
Entity a Voluntary Filer	No
Entity's Reporting Status Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business Flag	true
Entity Emerging Growth Company	false
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Public Float			$ 52,100,000
Entity Common Stock, Shares Outstanding		19,562,020
Trading Symbol	CLSN
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2018

Consolidated Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 13,353,543	$ 11,444,055
Investment securities - available for sale, at fair value	14,257,998	12,724,020
Accrued interest receivable on investment securities	68,309	54,440
Advances and deposits on clinical programs and other current assets	451,293	89,186
Total current assets	28,131,143	24,311,701
Property and equipment (at cost, less accumulated depreciation and amortization)	184,627	175,771
Other assets:
In-process research and development, net	15,736,491	20,246,491
Goodwill	1,976,101	1,976,101
Other intangible assets, net	568,292	795,608
Deposits and other assets	258,933	8,761
Total other assets	18,539,817	23,026,961
Total assets	46,855,587	47,514,433
Current liabilities:
Accounts payable - trade	3,020,638	3,416,863
Other accrued liabilities	2,585,898	2,282,827
Deferred revenue - current portion	500,000	500,000
Total current liabilities	6,106,536	6,199,690
Earn-out milestone liability	8,907,664	12,538,525
Note Payable, net of deferred financing costs	9,417,037
Deferred revenue - non-current portion	1,500,000	2,000,000
Other liabilities - non-current	63,278	71,710
Total liabilities	25,994,515	20,809,925
Commitments
Stockholders' equity:
Preferred Stock - $0.01 par value (100,000 shares authorized, and no shares issued or outstanding at December 31, 2018 and 2017)
Common stock - $0.01 par value (112,500,000 shares authorized; 18,832,168 and 17,277,299 shares issued at December 31, 2018 and 2017, respectively, and 18,831,834 and 17,276,965 shares outstanding at December 31, 2018 and 2017, respectively)	188,322	172,772
Additional paid-in capital	294,393,313	288,408,976
Accumulated other comprehensive gain (loss)	29,872	(10,164)
Accumulated deficit	(273,665,247)	(261,781,888)
Total stockholders' equity before treasury stock	20,946,260	26,789,696
Treasury stock, at cost (334 shares at December 31, 2018 and 2017)	(85,188)	(85,188)
Total stockholders' equity	20,861,072	26,704,508
Total liabilities and stockholders' equity	$ 46,855,587	$ 47,514,433

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	112,500,000	112,500,000
Common stock, shares issued	18,832,168	17,277,299
Common stock, shares outstanding	18,831,834	17,276,965
Treasury stock, shares	334	334

Consolidated Statements of Operations - USD ($)	12 Months Ended
Consolidated Statements of Operations - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Technology development and licensing revenue	$ 500,000	$ 500,000
Operating expenses:
Research and development	11,865,523	13,078,710
General and administrative	9,699,521	5,889,722
Total operating expenses	21,565,044	18,968,432
Loss from operations	(21,065,044)	(18,468,432)
Other income (expense):
Gain from change in earn-out milestone liability	3,630,861	649,701
Impairment of in-process research and development	(4,510,000)	(2,520,000)
Investment income, net	353,682	26,041
Interest expense	(712,025)	(91,756)
Other income	52	2,270
Total other expense	(1,237,430)	(1,933,744)
Net loss before income tax benefit	(22,302,474)	(20,402,176)
Income tax benefit	10,419,115
Net loss	(11,883,359)	(20,402,176)
Deemed dividend related to warrant modification		(345,685)
Net loss attributable to common shareholders	$ (11,883,359)	$ (20,747,861)
Net loss attributable to common shareholders per common share - basic and diluted	$ (0.68)	$ (2.72)
Weighted average common shares outstanding - basic and diluted	17,582,879	7,627,210

Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
Consolidated Statements of Comprehensive Loss - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (11,883,359)	$ (20,402,176)
Changes in:
Realized loss on investment securities recognized in investment income, net	10,164
Unrealized gain (loss) on investment securities	29,872	(10,164)
Other comprehensive income (loss)	40,036	(10,164)
Comprehensive loss	$ (11,843,323)	$ (20,412,340)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (11,883,359)	$ (20,402,176)
Non-cash items included in net loss:
Depreciation and amortization	356,859	553,010
Change in fair value of earn-out milestone liability	(3,630,861)	(649,701)
Impairment of in-process research and development	4,510,000	2,520,000
Stock-based compensation	4,604,415	1,105,245
Shares issued in exchange for services	29,841
Shares issued to satisfy certain obligations		235,072
Amortization of deferred finance charges and debt discount associated with note payable	199,153	35,370
Change in deferred rent liability	(8,432)	59,358
Net changes in:
Interest receivable on investments	(13,869)	(50,432)
Advances and deposits on clinical programs and other current assets	(362,107)	115,222
Other assets	(250,172)
Accounts payable - trade	(396,225)	537,885
Deferred revenue	(500,000)	(500,000)
Other accrued liabilities	303,071	(200,929)
Net cash used in operating activities	(7,041,686)	(16,642,076)
Cash flows from investing activities:
Purchases of investment securities	(16,973,942)	(12,734,184)
Proceeds from sale and maturity of investment securities	15,480,000	1,680,000
Refund on security for letter of credit		100,000
Purchases of property and equipment	(138,399)	(38,629)
Net cash (used in) provided by investing activities	(1,632,341)	(10,992,813)
Cash flows from financing activities:
Proceeds from issuance of common stock equity, net of issuance costs	858,515	17,910,401
Proceeds from note payable, net of issuance costs	9,725,000
Proceeds from exercise of common stock warrants		21,140,304
Principal payments on note payable		(2,595,923)
Net cash provided by financing activities	10,583,515	36,454,782
Increase in cash and cash equivalents	1,909,488	8,819,893
Cash and cash equivalents at beginning of period	11,444,055	2,624,162
Cash and cash equivalents at end of period	13,353,543	11,444,055
Cash (paid for) received from:
Interest paid	(512,872)	(56,386)
Income tax benefit	10,419,115
Non-cash financing activities:
Fair value of common stock issued as equity issuance costs charged against paid in capital	450,000
Fair value of common stock and warrants issued in connection with notes payable	507,116
Fair value of stock issued in exchange for cancelation of warrants	8,207
Fair value of modification of warrant exercise prices included in paid in capital		345,685
Fair value of deemed dividend related to modification of warrant exercise prices charged against paid in capital		$ (345,685)

Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2016	$ 22,305	$ 248,168,421	$ (85,188)		$ (241,379,712)	$ 6,725,826
Balance, shares at Dec. 31, 2016	2,230,118		334
Net loss					(20,402,176)	(20,402,176)
Registered direct and ATM common stock offerings	$ 72,964	17,837,437				17,910,401
Registered direct and ATM common stock offerings, shares	7,296,352
Exercise of common stock warrants	$ 76,171	21,064,133				21,140,304
Exercise of common stock warrants, shares	7,617,148
Shares issued to satisfy certain obligations	$ 1,301	233,771				235,072
Shares issued to satisfy certain obligations, shares	130,055
Realized and unrealized gains and losses, net, on investments securities				(10,164)		(10,164)
Stock-based compensation expense		1,105,245				1,105,245
Issuance of restricted stock	$ 34	(34)
Issuance of restricted stock, shares	3,357
Modification of warrant exercise prices		345,685				345,685
Deemed dividend related to warrant exercise price modifications		(345,685)				(345,685)
Effect of reverse stock split	$ (3)	3
Effect of reverse stock split, shares	(65)
Balance at Dec. 31, 2017	$ 172,772	288,408,976	$ (85,188)	(10,164)	(261,781,888)	26,704,508
Balance, shares at Dec. 31, 2017	17,276,965		334
Net loss					(11,883,359)	(11,883,359)
Realized and unrealized gains and losses, net, on investments securities				40,036		40,036
Stock-based compensation expense		4,604,415				4,604,415
Issuance of restricted stock	$ 123	29,718				29,841
Issuance of restricted stock, shares	12,250
Sale of equity through ATM and common stock purchase agreement	$ 5,572	983,528				989,100
Sale of equity through ATM and common stock purchase agreement, shares	557,070
Common stock issuance in exchange for cancellation of common stock warrants	$ 8,207	(138,792)				(130,585)
Common stock issuance in exchange for cancellation of common stock warrants, shares	820,714
Common stock and warrants to purchase common stock issued in connection with equity and debt facilities	$ 1,648	505,468				507,116
Common stock and warrants to purchase common stock issued in connection with equity and debt facilities, shares	164,835
Balance at Dec. 31, 2018	$ 188,322	$ 294,393,313	$ (85,188)	$ 29,872	$ (273,665,247)	$ 20,861,072
Balance, shares at Dec. 31, 2018	18,831,834		334

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Description of Business

Celsion Corporation (“Celsion” and the “Company”) is a fully-integrated development stage oncology drug company focused on advancing a portfolio of innovative cancer treatments, including directed chemotherapies, DNA-mediated immunotherapy and RNA based therapies. Our lead product candidate is ThermoDox ^®, a proprietary heat-activated liposomal encapsulation of doxorubicin, currently in a Phase III clinical trial for the treatment of primary liver cancer (the “OPTIMA Study”). Second in our pipeline is GEN-1, a DNA-mediated immunotherapy for the localized treatment of ovarian cancer. We have two platform technologies providing the basis for the future development of a range of therapeutics for difficult-to-treat forms of cancer including: Lysolipid Thermally Sensitive Liposomes, a heat sensitive liposomal based dosage form that targets disease with known therapeutics in the presence of mild heat and TheraPlas, a novel nucleic acid-based treatment for local transfection of therapeutic plasmids. With these technologies we are working to develop and commercialize more efficient, effective and targeted oncology therapies that maximize efficacy while minimizing side-effects common to cancer treatments

Basis of Presentation

The accompanying consolidated financial statements of Celsion have been prepared in accordance with generally accepted accounting principles (“GAAP”) in the United States and include the accounts of the Company and CLSN Laboratories, Inc. All intercompany balances and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make judgments, estimates, and assumptions that affect the amount reported in the Company’s financial statements and accompanying notes. Actual results could differ materially from these estimates.

Events and conditions arising subsequent to the most recent balance sheet date through the date of the issuance of these consolidated financial statements have been evaluated for their possible impact on the financial statements and accompanying notes. No events and conditions would give rise to any information that required accounting recognition or disclosure in the financial statements other than those arising in the ordinary course of business.

Use of Estimates

The preparation of financial statements in conformity with US GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period.

On an ongoing basis, the Company evaluates its estimates using historical experience and other factors, including the current economic environment. Significant items subject to such estimates are assumptions used for purposes of determining stock-based compensation, the fair value of the convertible notes, and accounting for research and development activities. Management believes its estimates to be reasonable under the circumstances. Actual results could differ significantly from those estimates. Significant estimates in these financials are the valuation of options granted and valuation methods used to determine the recoverability of goodwill and other intangible assets.

Revenue Recognition

On January 1, 2018, the Company adopted the new accounting standard ASC 606, Revenue from Contracts with Customers and all related amendments (the “new revenue standard”) to all contracts with customers using the modified retrospective method. The adoption of the new revenue standard had no impact on retained earnings as of December 31, 2017 and, accordingly, no cumulative adjustment was required. We do not expect the new revenue standard to have a significant impact on our net income on an ongoing basis. The Company’s sole revenue stream is related to the Hisun agreement described in Note 16. There were no accounts receivable as of December 31, 2018 or 2017. Contract liabilities from the Hisun agreement amounted to $1,500,000 and $2,000,000 at December 31, 2018 and 2017, respectively. Contract liabilities values represent the value of cash received before the services were provided. In accordance with ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company received or expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. At contract inception, the Company assesses the goods or services promised within each contract that falls under the scope of ASC 606, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. The application of these five steps necessitates the development of assumptions that require judgment to determine the stand-alone selling price, which may include forecasted revenues, development timelines and probabilities of technical and regulatory success.

Cash and Cash Equivalents

Cash and cash equivalents include cash on hand and investments purchased with an original maturity of three months or less. A portion of these funds are not covered by FDIC insurance.

Fair Value of Investment Securities

The carrying values of investment securities approximate their respective fair values.

Short Term Investments

The Company classifies its investments in marketable securities with readily determinable fair values as investments available-for-sale in accordance with Accounting Standards Codification (ASC) 320, Investments - Debt and Equity Securities. Available-for-sale securities consist of debt and equity securities not classified as trading securities or as securities to be held to maturity. The Company has classified all of its investments as available-for-sale. Unrealized holding gains and losses on available-for-sale securities are reported as a net amount in accumulated other comprehensive gain or loss in stockholders’ equity until realized. Gains and losses on the sale of available-for-sale securities are determined using the specific identification method. The Company’s short-term investments consist of corporate bonds.

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is provided over the estimated useful lives of the related assets, ranging from three to seven years, using the straight-line method. Amortization is recognized over the lesser of the life of the asset or the lease term. Major renewals and improvements are capitalized at cost and ordinary repairs and maintenance are charged against operating expenses as incurred. Depreciation expense was approximately $130,000 and $326,000 for the years ended December 31, 2018 and 2017, respectively.

The Company reviews property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An asset is considered impaired if its carrying amount exceeds the future net undiscounted cash flows that the asset is expected to generate. If such asset is considered to be impaired, the impairment recognized is the amount by which the carrying amount of the asset, if any, exceeds its fair value determined using a discounted cash flow model.

Deposits

Deposits include real property security deposits and other deposits which are contractually required and of a long-term nature.

In-Process Research and Development, Other Intangible Assets and Goodwill

During 2014, the Company acquired certain assets of EGEN, Inc. As more fully described in Note 5, the acquisition was accounted for under the acquisition method of accounting which required the Company to perform an allocation of the purchase price to the assets acquired and liabilities assumed. Under the acquisition method of accounting, the total purchase price is allocated to net tangible and intangible assets and liabilities based on their estimated fair values as of the acquisition date.

Impairment or Disposal of Long-Lived Assets

The Company assesses the impairment of its long-lived assets under accounting standards for the impairment or disposal of long-lived assets whenever events or changes in circumstances indicate that the carrying value may not be recoverable. For long-lived assets to be held and used, the Company recognizes an impairment loss only if its carrying amount is not recoverable through its undiscounted cash flows and measures the impairment loss based on the difference between the carrying amount and fair value.

Comprehensive Income (Loss)

Accounting Standards Codification (“ASC”) 220, Comprehensive Income, establishes standards for the reporting and display of comprehensive income (loss) and its components in the Company’s consolidated financial statements. The objective of ASC 220 is to report a measure comprehensive income (loss) of all changes in equity of an enterprise that result from transactions and other economic events in a period other than transactions with owners. Comprehensive gains (losses) result from changes in unrealized gains and losses from investment securities.

Research and Development

Research and development costs are expensed as incurred. Equipment and facilities acquired for research and development activities that have alternative future uses are capitalized and charged to expense over their estimated useful lives.

Net Loss Per Common Share

Basic and diluted net loss per common share was computed by dividing net loss for the year by the weighted average number of shares of common stock outstanding, both basic and diluted, during each period. The impact of common stock equivalents has been excluded from the computation of diluted weighted average common shares outstanding in periods where there is a net loss, as their effect is anti-dilutive.

For the years ended December 31, 2018 and 2017, the total number of shares of common stock issuable upon exercise of warrants and equity awards is 4,764,405 and 3,761,844 respectively. For the year ended December 31, 2018 and 2017, diluted loss per common share is the same as basic loss per common share as all options and all warrants that were convertible into shares of the Company’s common stock were excluded from the calculation of diluted earnings attributable to common stockholders per common share as their effect would be anti-dilutive.

Income Taxes

Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax asset and liabilities of a change in tax rates is recognized in results of operations in the period that the tax rate change occurs. Valuation allowances are established, when necessary, to reduce deferred tax assets to the amount expected to be realized. In accordance with ASC 740, Income Taxes, a tax position is recognized as a benefit only if it is “more likely than not” that the tax position taken would be sustained in a tax examination, presuming that a tax examination will occur. The Company recognizes interest and/or penalties related to income tax matters in the income tax expense category.

As more fully discussed in Note 9, the Company the Company completed the sale of a portion of its New Jersey net operating losses totaling approximately $11.1 for net proceeds of approximately $10.4 million. Such proceeds are reflected as a tax benefit for the year ended December 31, 2018.

Stock-Based Compensation

In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation, which simplifies various aspects of accounting for share-based payments. The areas for simplification involve several aspects of the accounting for share-based payment transactions, including the income tax consequences and classification on the statements of cash flows. The Company adopted the standard during the first quarter of 2017 and has elected to recognize the effect of forfeitures in compensation cost when they occur.

Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) and are adopted by us as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued accounting pronouncements will not have a material impact on the Company’s consolidated financial position, results of operations, and cash flows, or do not apply to our operations.

In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-09 “Revenue from Contracts with Customers (Topic 606),” which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. ASU 2014 - 09 was originally going to be effective on January 1, 2017; however, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606) - Deferral of the Effective Date,” which deferred the effective date of ASU 2014-09 by one year to January 1, 2018. In March 2016, the FASB issued ASU No. 2016 - 8, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations. The amendments in this ASU do not change the core principle of ASU No. 2014 - 09 but the amendments clarify the implementation guidance on reporting revenue gross versus net. The effective date for the amendments in this ASU is the same as the effective date of ASU No. 2014-09. In April 2016, the FASB issued ASU No. 2016-10, “Revenue from Contracts with Customers (Identifying Performance Obligations and Licensing),” to clarify the implementation guidance on identifying performance obligations and licensing (collectively “the new revenue standards”). The new revenue standards allow for either “full retrospective” adoption, meaning the standard is applied to all periods presented, or “modified retrospective” adoption, meaning the standard is applied only to the most current period presented in the financial statements. The new revenue standard became effective for us on January 1, 2018. Under the new revenue standards, we recognize revenue following a five-step model prescribed under ASU No. 2014-09; (i) identify contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenues when (or as) we satisfy the performance obligation. As further described in Note 16, the Company currently has only one contract subject to the new revenue standards. After performance of the five-step model discussed above, the Company concluded the adoption of the new revenue standards as of January 1, 2018 did not change our revenue recognition policy nor does it have an effect on our financial statements using either the full retrospective or the modified retrospective adoption methods.

In January 2016, the FASB issued Accounting Standards Update No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities,” which requires that most equity investments be measured at fair value, with subsequent changes in fair value recognized in net income (other than those accounted for under the equity method of accounting). This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. Based on the Company’s evaluation, the adoption of the ASU 2016-01 does not have a material impact on its consolidated financial statements or its disclosures.

In February 2016, the FASB issued Accounting Standards Update No. 2016-02, “Leases” (Topic 842), which requires that lessees recognize assets and liabilities for leases with lease terms greater than twelve months in the statement of financial position. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. This update also requires improved disclosures to help users of financial statements better understand the amount, timing and uncertainty of cash flows arising from leases. The update is effective for fiscal years beginning after December 15, 2018, including interim reporting periods within that reporting period. The FASB subsequently issued the following amendments to ASU 2016-02, which have the same effective date and transition date of January 1, 2019:

	●	ASU No. 2018-10, Codification Improvements to Topic 842, Leases, which amends certain narrow aspects of the guidance issued in ASU 2016-02; and

	●	ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which allows for a transition approach to initially apply ASU 2016-02 at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption as well as an additional practical expedient for lessors to not separate non-lease components from the associated lease component.

We evaluated ASU 2016-02 and its impact on the consolidated financial statements and related disclosures. We have identified all of our leases which consist of the New Jersey corporate office lease and the Alabama lab facility lease, see Note 17, and we estimate the adoption of this standard will result in the recognition of right-of-use assets and related lease liabilities on the consolidated balance sheets as of January 1, 2019 of approximately $1.1 to $1.3 million related to our operating lease commitments, with no material impact to the opening balance of retained earnings.

In January 2017, the FASB issued Accounting Standard Update No. 2017-04, “Intangibles-Goodwill and Other, Simplifying the Test for Goodwill Impairment,” which eliminated Step 2 from the goodwill impairment test. Under the revised test, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for any interim or annual impairment tests for fiscal years beginning after December 15, 2019, with early adoption permitted. The Company adopted this method for its impairment testing of goodwill during 2017 and 2018. Based on the Company’s evaluation, the adoption of the ASU 2017-04 did not have any material impact on its consolidated financial statements or its disclosures.

Financial Condition

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Financial Condition

2. FINANCIAL CONDITION

Since inception, the Company has incurred substantial operating losses, principally from expenses associated with the Company’s research and development programs, clinical trials conducted in connection with the Company’s product candidates, and applications and submissions to the U.S. Food and Drug Administration. We have not generated significant revenue and have incurred significant net losses in each year since our inception. We have incurred approximately $274 million of cumulated net losses. As of December 31, 2018, we had approximately $27.7 million in cash, investment securities and interest receivable. We have substantial future capital requirements to continue our research and development activities and advance our product candidates through various development stages. The Company believes these expenditures are essential for the commercialization of its technologies.

The Company expects its operating losses to continue for the foreseeable future as it continues its product development efforts, and when it undertakes marketing and sales activities. The Company’s ability to achieve profitability is dependent upon its ability to obtain governmental approvals, manufacture, and market and sell its new product candidates. There can be no assurance that the Company will be able to commercialize its technology successfully or that profitability will ever be achieved. The operating results of the Company have fluctuated significantly in the past. We have substantial future capital requirements associated with our continued research and development activities and to advance our product candidates through various stages of development. The Company believes these expenditures are essential for the commercialization of its technologies.

The actual amount of funds the Company will need to operate is subject to many factors, some of which are beyond the Company’s control. These factors include the following:

	●	the progress of research activities;

	●	the number and scope of research programs;

	●	the progress of preclinical and clinical development activities;

	●	the progress of the development efforts of parties with whom the Company has entered into research and development agreements;

	●	the costs associated with additional clinical trials of product candidates;

	●	the ability to maintain current research and development licensing arrangements and to establish new research and development and licensing arrangements;

	●	the ability to achieve milestones under licensing arrangements;

	●	the costs involved in prosecuting and enforcing patent claims and other intellectual property rights; and

	●	the costs and timing of regulatory approvals.

The Company has based its estimate on assumptions that may prove to be wrong. The Company may need to obtain additional funds sooner or in greater amounts than it currently anticipates. Potential sources of financing include strategic relationships, public or private sales of the Company’s shares or debt, the additional sales from the sale of its State of New Jersey net operating losses in the future and other sources. If the Company raises funds by selling additional shares of common stock or other securities convertible into common stock, the ownership interest of existing stockholders may be diluted.

Annually, the State of New Jersey enables approved technology and biotechnology businesses with New Jersey net operating tax losses the opportunity to sell these losses through the Technology Business Tax Certificate Program (the “NOL Program”), thereby providing cash to companies to help fund their operations. The Company determined it met the eligibility requirements of the NOL Program for 2018 and filed its application with the New Jersey Economic Development Authority (NJEDA) in June 2018. In this application, the Company requested authorization of up to $12.5 million in tax benefits from its cumulative New Jersey net operating losses to be eligible for sale. In September 2018, the NJEDA notified the Company that its application received approval under the NOL Program for 2018 and after receiving approval from the NJEDA to transfer $11.1 million of tax benefits in December 2018, the Company successfully transferred these approved tax benefits which resulted in receipt of $10.4 million in net cash proceeds to the Company at the end of 2018. The Company has approximately $3.9 million in future tax benefits remaining under the NOL Program for future years.

With $27.7 million in cash, investment securities and interest receivable at December 31, 2018, the Company believes it has sufficient capital resources to fund its operations into the third quarter of 2020. The Company will be required to obtain additional funding to continue development of its current product candidates within the anticipated time periods, if at all, and to continue to fund operations. As more fully discussed in Note 10, the Company has approximately $31 million available collectively for future sale of equity securities under a common stock purchase agreement with Aspire Capital Fund, LLC and a common stock sales agreement with JonesTrading International Services LLC.

Short Term Investments Available for Sale

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Short Term Investments Available for Sale

3. SHORT TERM INVESTMENTS AVAILABLE FOR SALE

Short-term investments available for sale of $14,257,998 and $12,724,020 as of December 31, 2018 and 2017, respectively, consist of corporate debt securities. These investments are valued at estimated fair value, with unrealized gains and losses reported as a separate component of stockholders’ equity in accumulated other comprehensive loss.

Securities available for sale are evaluated periodically to determine whether a decline in their value is other than temporary. The term “other than temporary” is not intended to indicate a permanent decline in value. Rather, it means that the prospects for near term recovery of value are not necessarily favorable, or that there is a lack of evidence to support fair values equal to, or greater than, the carrying value of the security. Management reviews criteria such as the magnitude and duration of the decline, as well as the reasons for the decline, to predict whether the loss in value is other than temporary. Once a decline in value is determined to be other than temporary, the value of the security is reduced and a corresponding charge to earnings is recognized.

A summary of the cost, fair value and maturities of the Company’s short-term investments is as follows:

	December 31, 2018				December 31, 2017
	Cost		Fair Value		Cost		Fair Value
Short-term investments
Corporate debt securities	$	14,228,126	$	14,257,998	$	12,734,184	$	12,724,020
Total	$	14,228,126	$	14,257,998	$	12,734,184	$	12,724,020

	December 31, 2018				December 31, 2017
	Cost		Fair Value		Cost		Fair Value
Short-term investment maturities
Within 3 months	$	5,383,488	$	5,393,743	$	-	$	-
Between 3-12 months		8,844,638		8,864,255		12,734,184		12,724,020
Total	$	14,228,126	$	14,257,998	$	12,734,184	$	12,724,020

The following table shows the Company’s investment securities gross unrealized gains (losses) and fair value by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31, 2018 and 2017. The Company has reviewed individual securities to determine whether a decline in fair value below the amortizable cost basis is other than temporary.

	December 31, 2018					December 31, 2017
Available for sale securities (all unrealized holding gains and losses are less than 12 months at date of measurement)	Fair Value		Unrealized Holding Gains (Losses)			Fair Value		Unrealized Holding Gains (Losses)

Investments with unrealized gains	$	7,515,676	$	38,068		$	748,148	$	570
Investments with unrealized losses		6,742,322		(8,196	)		11,975,872		(10,734	)
Total	$	14,257,998	$	29,872		$	12,724,020	$	(10,164	)

Investment income, which includes net realized losses on sales of available for sale securities and investment income interest and dividends, is summarized as follows:

	2018			2017
Interest and dividends accrued and paid	$	331,780		$	26,041
Accretion of investment discounts and premiums, net		32,066			-
Losses investment maturity and sales, net		(10,164	)		-
Investment income net	$	353,682		$	26,041

Fair Value of Financial Instruments

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

4. FAIR VALUES OF FINANCIAL INSTRUMENTS

FASB Accounting Standards Codification (ASC) Section 820 “Fair Value Measurements and Disclosures,” establishes a three-level hierarchy for fair value measurements which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value are as follows:

Level 1: Quoted prices (unadjusted) or identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date;

Level 2: Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data; and

Level 3: Significant unobservable inputs that reflect a reporting entity’s own assumptions that market participants would use in pricing an asset or liability.

Cash and cash equivalents, other current assets, accounts payable and other accrued liabilities are reflected in the condensed consolidated balance sheet at their approximate estimated fair values primarily due to their short-term nature. The fair values of securities available for sale is determined by relying on the securities’ relationship to other benchmark quoted securities and classified its investments as Level 2 items in both 2018 and 2017. There were no transfers of assets or liabilities between Level 1 and Level 2 and no transfers in or out of Level 3 during the year ended December 31, 2018 or 2017. The changes in Level 3 liabilities were the result of changes in the fair value of the earn-out milestone liability included in earnings and in-process R&D. The earnout milestone liability is valued using a risk-adjusted assessment of the probability of payment of each milestone, discounted to present value using an estimated time to achieve the milestone (see Note 12). The in-process R&D – GBM is valued using a multi-period excess earnings method (see note 5).

Assets and liabilities measured at fair value are summarized below:

	Total Fair Value		Quoted Prices In Active Markets For Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:

Recurring items as of December 31, 2018
Corporate debt securities, available for sale	$	14,257,998	$	─	$	14,257,998	$	─

Recurring items as of December 31, 2017
Corporate debt securities, available for sale	$	12,724,020	$	─	$	12,724,020	$	─

Liabilities:

Recurring items as of December 31, 2018
Earn-out milestone liability (Note 12)	$	8,907,664	$	─	$	─	$	8,907,664

Non-recurring items as of December 31, 2018
In process R&D (Note 5)	$	15,736,491	$	─	$	─	$	15,736,491

Recurring items as of December 31, 2017
Earn-out milestone liability (Note 12)	$	12,538,525	$	─	$	─	$	12,538,525

Non-recurring items as of December 31, 2017
In process R&D (Note 5)	$	20,246,491	$	─	$	─	$	20,246,491

Acquisition of EGEN, Inc.

12 Months Ended

Dec. 31, 2018

Business Combinations [Abstract]

Acquisition of EGEN, Inc.

5. ACQUISITION OF EGEN, INC.

On June 20, 2014, we completed the acquisition of substantially all of the assets of EGEN, Inc., an Alabama corporation, which has changed its company name to EGWU, Inc. after the closing of the acquisition (“EGEN”), pursuant to an Asset Purchase Agreement dated as of June 6, 2014, by and between EGEN and Celsion (the “Asset Purchase Agreement”). We acquired all of EGEN’s right, title and interest in and to substantially all of the assets of EGEN, including cash and cash equivalents, patents, trademarks and other intellectual property rights, clinical data, certain contracts, licenses and permits, equipment, furniture, office equipment, furnishings, supplies and other tangible personal property. In addition, CLSN Laboratories assumed certain specified liabilities of EGEN, including the liabilities arising out of the acquired contracts and other assets relating to periods after the closing date.

At the time of the acquisition, thew total purchase price for the asset acquisition was up to $44.4 million, including potential future earnout payments of up to $30.4 million contingent upon achievement of certain earnout milestones set forth in the Asset Purchase Agreement. We paid approximately $3.0 million in cash after the expense adjustment and issued 241,590 shares of our common stock to EGEN. The shares of common stock were issued in a private transaction exempt from registration under the Securities Act, pursuant to Section 4 (2) thereof.

The following table summarizes the fair values of these assets acquired and liabilities assumed related to the acquisition.

Property and equipment, net	$	35,000
In-process research and development		24,211,000
Other Intangible assets (Covenant not to compete)		1,591,000
Goodwill		1,976,000
Total assets:		27,813,000
Accounts payable and accrued liabilities		(235,000	)
Net assets acquired	$	27,578,000

Acquired In-process Research and Development

Acquired in-process research and development (IPR&D) consists of EGEN’s drug technology platforms: TheraPlas and TheraSilence. The fair value of the IPR&D drug technology platforms was estimated to be $24.2 million as of the acquisition date. As of the closing of the acquisition, the IPR&D was considered indefinite lived intangible assets and will not be amortized. IPR&D is reviewed for impairment at least annually as of our third quarter ended September 30, and whenever events or changes in circumstances indicate that the carrying value of the assets might not be recoverable.

At December 31, 2016, the Company determined one of the IPR&D assets related to the development of its RNA delivery system being developed with collaborators using their RNA product candidates may be impaired and after an assessment, the Company concluded that this asset, valued at $1.4 million, was impaired. Therefore, the Company wrote off the value of this IPR&D asset, incurring a non-cash charge of $1.4 million in the fourth quarter of 2016.

At September 30, 2018 and 2017, after the Company’s annual assessments of the totality of the events that could impair IPR&D, the Company determined certain IPR&D assets related to the development of its glioblastoma multiforme cancer (GBM) product candidate may be impaired. To arrive at this determination, the Company assessed the status of studies in GBM conducted by its competitors and the Company’s strategic commitment of resources to its studies in primary liver cancer and ovarian cancer. The Company estimated the fair value of the IPR&D related to GBM at September 30, 2018 and 2017 using the multi-period excess earnings method (MPEEM). Significant unobservable assumptions used by the Company in the MPEEM model are potential FDA approval, commercialization dates, dosage pricing, profitability and present value factor. After its assessment on September 30, 2017, the Company concluded that the GBM asset, valued at $9.4 million, was partially impaired and wrote down the GBM asset to $6.9 million on September 30, 2017, incurring a non-cash charge of $2.5 million in the third quarter of 2017. After its assessment on September 30, 2018, the Company concluded that the GBM asset, valued at $6.9 million, was partially impaired and wrote down the GBM asset to $2.4 million on September 30, 2018, incurring a non-cash charge of $4.5 million in the third quarter of 2018. After recognizing the impairment related to the IPR&D costs of $4,510,000 in 2018 and $2,520,000 in 2017, the resulting carrying value of its IPR&D costs totaled $15,736,491 and $20,246,491 at December 31, 2018 and 2017, respectively.

At September 30, 2018 and 2017, the Company evaluated its IPR&D of the ovarian cancer indication and concluded that it is not more likely than not that the asset is impaired. As no other indicators of impairment existed during the fourth quarter of 2018, the Company concluded none of the other IPR&D assets were impaired at December 31, 2018. The carrying amount of the ovarian cancer indication was $13.3 million at December 31, 2018 and 2017.

Covenants Not To Compete

Pursuant to the EGEN Purchase Agreement, EGEN provided certain covenants (“Covenant Not To Compete”) to the Company whereby EGEN agreed, during the period ending on the seventh anniversary of the closing date of the acquisition on June 20, 2014, not to enter into any business, directly or indirectly, which competes with the business of the Company nor will it contact, solicit or approach any of the employees of the Company for purposes of offering employment. The Covenant Not to Compete which was valued at approximately $1.6 million at the date of the EGEN acquisition has a definitive life and is amortized on a straight-line basis over its life of 7 years. The Company recognized amortization expense of $227,316 in 2018 and 2017. The carrying value of the Covenant Not to Compete was $568,292, net of $1,022,922 accumulated amortization, as of December 31, 2018 and $795,608, net of $795,606 accumulated amortization, respectively, as of December 31, 2017

Following is a schedule of future amortization amounts during the remaining life of the Covenant Not to Compete.

	Year Ended December 31,
2019	$	227,316
2020		227,316
2021		113,660
Total	$	568,292

Goodwill

The purchase price exceeded the estimated fair value of the net assets acquired by approximately $2.0 million which was recorded as Goodwill. Goodwill represents the difference between the total purchase price for the net assets purchased from EGEN and the aggregate fair values of tangible and intangible assets acquired, less liabilities assumed. Goodwill is reviewed for impairment at least annually as of our third quarter ended September 30 or sooner if we believe indicators of impairment exist. As of September 30, 2018, we concluded that the Company’s fair value exceeded its carrying value therefore “it is not more likely than not” that the Goodwill was impaired. As no other indicators of impairment existed during the fourth quarter of 2018, the Company concluded it is “not more likely than not” Goodwill was impaired.

Following is a summary of the net fair value of the assets acquired in the EGEN acquisition for the two years ended December 31, 2018:

	IPR&D			Goodwill		Covenant Not To Compete

Balance at January 1, 2017, net	$	22,766,491		$	1,976,101		1,022,924
Amortization		-			-		(227,316	)
Impairment charge		(2,520,000	)		-		-
Balance at December 31, 2017, net		20,246,491			1,976,101		795,608
Amortization		-			-		(227,316	)
Impairment charge		(4,510,000	)		-		-
Balance at December 31, 2018, net		15,736,491			1,976,101		568,292

Property and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment

6. PROPERTY AND EQUIPMENT

	Year Ended December 31,
	2018			2017
Machinery and equipment (5-7 year life)	$	2,596,170		$	2,495,959
Furniture and fixtures (3-5 year life)		267,712			248,709
Leasehold improvements (5-7 year life)		289,004			269,819
		3,152,886			3,014,487
Less accumulated depreciation and amortization		(2,968,259	)		(2,838,716	)
Total	$	184,627		$	175,771

Other Accrued Liabilities

12 Months Ended

Dec. 31, 2018

Payables and Accruals [Abstract]

Other Accrued Liabilities

7. OTHER ACCRUED LIABILITIES

Other accrued liabilities at December 31, 2018 and 2017 include the following:

	Year Ended December 31,
	2018		2017
Amounts due to contract research organizations and other contractual agreements	$	749,369	$	665,373
Accrued payroll and related benefits		1,592,590		1,258,265
Accrued professional fees		198,654		264,668
Other		45,285		94,521
Total	$	2,585,898	$	2,282,827

Notes Payable

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Notes Payable

8. NOTES PAYABLE

Horizon Credit Agreement

On June 27, 2018, the Company entered into a loan agreement with Horizon Technology Finance Corporation (“Horizon”) that provided $10 million in new capital (the “Horizon Credit Agreement”). The Company drew down $10 million upon closing of the Horizon Credit Agreement on June 27, 2018. The Company will use the funding provided under the Horizon Credit Agreement for working capital and advancement of its product pipeline.

The obligations under the Horizon Credit Agreement are secured by a first-priority security interest in substantially all assets of Celsion other than intellectual property assets. The obligations will bear interest at a rate calculated based on one-month LIBOR plus 7.625%. The effective interest rate at December 31, 2018 was 9.98%. Payments under the loan agreement are interest only for the first twenty-four (24) months after loan closing, followed by a 24-month amortization period of principal and interest through the scheduled maturity date. At its option, the Company can prepay all of the outstanding principal balance by prepaying the outstanding principal balance and an amount equal to 1-3% of the outstanding principal balance at that time, based on the amount of time prior to the maturity date of the notes.

The Horizon Credit Agreement contains customary representations, warranties and affirmative and negative covenants including, among other things, covenants that limit or restrict Celsion’s ability to grant liens, incur indebtedness, make certain restricted payments, merge or consolidate and make dispositions of assets. Upon the occurrence of an event of default under the Horizon Credit Agreement, the lenders may cease making loans, terminate the Horizon Credit Agreement, declare all amounts outstanding to be immediately due and payable and foreclose on or liquidate Celsion’s assets that comprise the lenders’ collateral. The Horizon Credit Agreement specifies a number of events of default (some of which are subject to applicable grace or cure periods), including, among other things, non-payment defaults, covenant defaults, a material adverse effect on Celsion or its assets, cross-defaults to other material indebtedness, bankruptcy and insolvency defaults and material judgment defaults.

As a fee in connection with the Horizon Credit Agreement, Celsion issued Horizon warrants exercisable for a total of 190,114 shares of Celsion’s common stock (the “Horizon Warrants”) at a per share exercise price of $2.63. The Horizon Warrants are immediately exercisable for cash or by net exercise from the date of grant and will expire after ten years from the date of grant. Celsion registered the Horizon Warrants on Form S-3 (File No. 333 - 227236) filed with the Securities and Exchange Commission on September 7, 2018 and declared effective on October 10, 2018. The Company valued the Horizon Warrants issued using the Black-Scholes option pricing model and recorded a total of $507,116 as a direct deduction from the debt liability consistent with the presentation of a debt discount and are being amortized as interest expense using the effective interest method over the life of the loan.

In connection with the Horizon Credit Agreement, the Company incurred financing fees and expenses totaling $175,000 which are recorded and classified as debt discount. In addition, the Company paid loan origination fees of $100,000 which has been recorded and classified as debt discount. These debt discount amounts totaling $782,116 are being amortized as interest expense using the effective interest method over the life of the loan. Also, in connection with each of the Horizon Credit Agreements, the Company is required to pay an end of term charge equal to 4.0% of the original loan amount at time of maturity. Therefore, these amounts totaling $400,000 are being amortized as interest expense using the effective interest method over the life of the loan.

During 2018, the Company incurred $512,872 in interest expense and amortized $199,153 respectively, as interest expense for debt discounts and end of term charges in connection with the Horizon Credit Agreement.

Following is a schedule of future principle payments, net of unamortized debt discounts and amortized end of term charges, due on the Horizon Credit Agreement:

	For the year ending December 31,
2019	$	-
2020		-
2021		4,583,333
2022		5,000,000
2023 and thereafter		416,667
Subtotal of future principle payments		10,000,000
Unamortized debt issuance costs, net		(582,963	)
Total	$	9,417,037

Hercules Credit Agreement

In November 2013, the Company entered into a loan agreement with Hercules Technology Growth Capital, Inc. (Hercules) which permits up to $20 million in capital to be distributed in multiple tranches (the Hercules Credit Agreement). The Company drew the first tranche of $5 million upon closing of the Hercules Credit Agreement in November 2013 and used approximately $4 million of the proceeds to repay the outstanding obligations under its loan agreement with Oxford Finance LLC and Horizon Technology Finance Corporation as discussed further below. On June 10, 2014, the Company closed the second $5 million tranche under the Hercules Credit Agreement. The proceeds were used to fund the $3.0 million upfront cash payment associated with Celsion’s acquisition of EGEN, as well as the Company’s transaction costs associated with the EGEN acquisition. Upon the closing of the second tranche, the Company had drawn down a total of $10 million under the Hercules Credit Agreement.

The obligations under the Hercules Credit Agreement were in the form of secured indebtedness bearing interest at a calculated prime-based variable rate (11.25% per annum since inception through December 17, 2015, 11.50% from December 18, 2015 through December 15, 2016 and 11.75% since). Payments under the loan agreement were interest only for the first twelve months after loan closing, followed by a 30 -month amortization period of principal and interest through the scheduled maturity date of June 1, 2017. In connection with the Hercules Credit Agreement, the Company incurred cash expenses of $122,378 which were recorded as deferred financing fees. These deferred financing fees were amortized as interest expense using the effective interest method over the life of the loan. In addition, the Company paid loan origination fees of $230,000 which has been classified as debt discount. This amount is being amortized as interest expense using the effective interest method over the life of the loan.

As a fee associated with the Hercules Credit Agreement, the Company issued Hercules a warrant for a total of 6,963 shares of the Company’s common stock (the Hercules Warrant) at a per share exercise price of $50.26, exercisable for cash or by net exercise from November 25, 2013. Upon the closing of the second tranche on June 10, 2014, this warrant became exercisable for an additional 6,963 shares of the Company’s common stock. The Hercules Warrant expired on November 25, 2018. Hercules has certain rights to register the common stock underlying the Hercules Warrant pursuant to a Registration Rights Agreement with the Company dated November 25, 2013. The registration rights expired on the date when such stock may be sold under Rule 144 without restriction or upon the first-year anniversary of the registration statement for such stock, whichever is earlier. The common stock issuable pursuant to the Hercules Warrant was filed pursuant to Rule 415 under the Securities Act of 1933 on the Prospectus for Registration Statement No. 333 - 193936 and was declared effective on September 30, 2014. The Company valued the Hercules Warrants issued using the Black-Scholes option pricing model and recorded a total of $476,261 as a direct deduction from the debt liability consistent with the presentation of a debt discount and are being amortized as interest expense using the effective interest method over the life of the loan. Also, in connection with each of the $5.0 million tranches, the Company was required to pay an end of term charge equal to 3.5% of each original loan amount at time of maturity. Therefore, these amounts totaling $350,000 were amortized as interest expense using the effective interest method over the life of the loan. The loan balance and end of term charges on the Hercules Credit Agreement was paid in full in June 2017. For 2017, the Company incurred $56,386 in interest expense and amortized $35,370 as interest expense for deferred fees, debt discount and end of term charges in connection with the Hercules Credit Agreement.

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

9. INCOME TAXES

On December 22, 2017, the President of the United States signed into law the Tax Reform Act. The Tax Reform Act significantly changes U.S. tax law by, among other things, lowering corporate income tax rates, implementing a quasi-territorial tax system, providing a one -time transition toll charge on foreign earnings, creating a new limitation on the deductibility of interest expenses and modifying the limitation on officer compensation. The Tax Reform Act permanently reduces the U.S. corporate income tax rate from a maximum of 35% to a flat 21% rate, effective January 1, 2018.

The income tax provision (benefit) for the years ended December 31, 2018 and 2017 consists of the following:

	2018			2017
Federal
Current	$	-		$	-
Deferred		-			-
State and Local		-			-
Current		(10,419,000	)		-
Deferred		-			-
Effective tax rate	$	(10,419,000	)		-

A reconciliation of the Company’s statutory tax rate to the effective rate for the years ended December 31, 2018 and 2017 is as follows:

	2018			2017
Federal statutory rate		21.0	%		21.0	%
State taxes, net of federal tax benefit		36.9			6.6
Permanent differences		(3.8	)		-
Other		(9.4	)		-
Change in valuation allowance and deferred rate change, net		2.0			(27.6	)
Effective tax rate		46.7	%		-	%

The components of the Company’s deferred tax asset as of December 31, 2018 and 2017 are as follows:

	December 31,
	2018			2017
Net operating loss carryforwards	$	51,498,000		$	62,216,000
Other Deferred tax assets, net		1,092,000			2,415,000
Subtotal		52,590,000			64,631,000
Valuation allowance		(52,590,000	)		(64,631,000	)
Total deferred tax asset	$	-		$	-

The evaluation of the realizability of such deferred tax assets in future periods is made based upon a variety of factors that affect the Company’s ability to generate future taxable income, such as intent and ability to sell assets and historical and projected operating performance. At this time, the Company has established a valuation reserve for all of its deferred tax assets. Such tax assets are available to be recognized and benefit future periods. As of December 31, 2018, the Company had net operating losses of approximately $229.7 million of which $222.2 million, if unused, will expire starting in 2023 through 2037. The Federal net operating loss generated for the year ended December 31, 2018 of approximately $7.5 million can be carried forward indefinitely. However, the deduction for net operating losses incurred in tax years beginning after January 1, 2018 is limited to 80% of annual taxable income

During 2018, 2017 and in prior years, the Company performed analyses to determine if there were changes in ownership, as defined by Section 382 of the Internal Revenue Code that would limit its ability to utilize certain net operating loss and tax credit carry forwards. The Company determined that it experienced ownership changes, as defined by Section 382, in connection with certain common stock offerings in July 2011, February 2013, June 2013, June 2015, February 2017, June 2017, October 2017 and August 2018. As a result, the utilization of the Company’s federal tax net operating loss carry forwards generated prior to the ownership changes are limited. As of December 31, 2018, the Company has net operating loss carry forwards for U.S. federal and state tax purposes of approximately $233 million, before excluding net operating losses that have been limited as a result of Section 382 limitations. The annual limitation due to Section 382 for net operating loss carry forward utilization is approximately $4.2 million per year for approximately $90 million in net operating loss carry forwards existing at the ownership change occurring in July 2011, approximately $1.4 million per year for approximately $34 million of additional net operating losses occurring from July 2011 to the ownership change that occurred in February 2013, approximately $1.5 million per year for approximately $4 million of additional net operating losses occurring from February 2013 to the ownership change that occurred in June 2013, approximately $1.6 million per year for approximately $40 million of additional net operating losses occurring from June 2013 to the ownership change that occurred in June 2015, approximately $0.3 million per year for approximately $35 million of additional net operating losses occurring from June 2015 to the ownership change that occurred in February 2017, approximately $0.3 million per year for approximately $7 million of additional net operating losses occurring from February 2017 to the ownership change that occurred in June 2017, approximately $0.8 million per year for approximately $5 million of additional net operating losses occurring from June 2017 to the ownership change that occurred in October 2017, and approximately $1.5 million per year for approximately $30 million of additional net operating losses occurring from October 2017 to the ownership change that occurred in August 2018. The utilization of these net operating loss carry forwards may be further limited if the Company experiences future ownership changes as defined in Section 382 of the Internal Revenue Code.

Sale of New Jersey Net Operating Losses

The Company received approval to sell a portion of the Company’s New Jersey NOLs as part of the Technology Business Tax Certificate Program sponsored by The New Jersey Economic Development Authority. Under the program, emerging biotechnology companies with unused NOLs and unused research and development credits are allowed to sell these benefits to other companies. In December 2018, the Company received cash proceeds of $10.4 million from the sale of NOLs. Such proceeds are reflected as a tax benefit for the year ended December 31, 2018.

Stockholders' Equity

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Stockholders' Equity

10. STOCKHOLDERS’ EQUITY

In September 2018, the Company filed with the SEC a new $75 million shelf registration statement on Form S-3 (the 2018 Shelf Registration Statement) (File No. 333-227236) that allows the Company to issue any combination of common stock, preferred stock or warrants to purchase common stock or preferred stock. This shelf registration was declared effective on October 12, 2018 and will expire three years from that date.

Increase in the Number of Authorized Shares

At the 2016 Annual Meeting of Stockholders of the Company in June 2016, the Company’s stockholders approved an increase in the number of the authorized shares of the Company’s common stock from 75,000,000 shares to 112,500,000 shares. The number of the authorized shares of preferred stock remains at 100,000 shares. The aggregate number of shares of all classes of stock that the Company may issue, after giving effect to such amendment as approved by the stockholders, will be 112,600,000 shares.

Reverse Stock Split

On May 26, 2017, the Company effected a 14-for-1 reverse stock split of its common stock which was made effective for trading purposes as of the commencement of trading on May 30, 2017. As of that date, each 14 shares of issued and outstanding common stock and equivalents was consolidated into one share of common stock. All shares have been restated to reflect the effects of the 14 -for- 1 reverse stock split. In addition, at the market open on May 30, 2017, the Company’s common stock started trading under a new CUSIP number 15117N503 although the Company’s ticker symbol, CLSN, remained unchanged.

The reverse stock split was previously approved by the Company’s stockholders at the 2017 Annual Meeting held on May 16, 2017, and the Company subsequently filed a Certificate of Amendment to its Certificate of Incorporation to effect the stock consolidation. The primary reasons for the reverse stock split and the amendment are:

	●	To increase the market price of the Company’s common stock making it more attractive to a broader range of institutional and other investors, and
	●	To provide the Company with additional capital resources and flexibility sufficient to execute its business plans including the establishment of strategic relationships with other companies and to ensure its ability to raise additional capital as necessary.

Immediately prior to the reverse stock split, the Company had 56,982,418 shares of common stock outstanding which consolidated into 4,070,172 shares of the Company’s common stock. No fractional shares were issued in connection with the reverse stock split. Holders of fractional shares have been paid out in cash for the fractional portion with the Company’s overall exposure for such payouts consisting of a nominal amount. The number of outstanding options and warrants were adjusted accordingly, with outstanding options being reduced from approximately 2.4 million to approximately 0.2 million and outstanding warrants being reduced from approximately 33.5 million to approximately 2.4 million.

October 2017 Underwritten Offering

On October 27, 2017, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with Oppenheimer& Co. Inc. (the “Underwriter”), relating to the issuance and sale (the “Offering”) of 2,640,000 shares (the “Shares”) of the Company’s common stock, $0.01 par value per share (the “Common Stock”), and warrants to purchase an aggregate of 1,320,000 shares of Common Stock. Each share of Common Stock is being sold together with 0.5 warrants (the “Investor Warrants”), each whole Investor Warrant being exercisable for one share of Common Stock, at an offering price of $2.50 per share and related Investor Warrants.

Pursuant to the terms of the Underwriting Agreement, the Underwriter agreed to purchase the Shares and related Investor Warrants from the Company at a price of $2.325 per share and related Investor Warrants. Each Investor Warrant is exercisable six months from the date of issuance. The Investor Warrants have an exercise price of $3.00 per whole share and expire five years from the date first exercisable. On October 26, 2018, the Company and the holders of the Investor Warrants entered into Warrant Exchange Agreements (the “Exchange Agreements”) whereby each of the holders of the Investor Warrants elected to surrender Investor Warrants, representing 1,320,000 shares of Common Stock collectively. In exchange for the surrender of the Investor Warrants, these holders received 820,714 shares of Common Stock. In connection with this exchange and the exchange discussed below with 321,428 warrants from the February 14, 2017 Public Offering, the Company incurred approximately $130,000 of broker and legal fees which are presented as a component of stockholders equity.

The Company received $6.6 million of gross proceeds from the sale of the Shares and Investor Warrant. This Offering was made pursuant to the Company’s effective shelf registration statement on Form S- 3 (File No. 333 - 206789) filed with the Securities and Exchange Commission on September 4, 2015, and declared effective on September 25, 2015, including the base prospectus dated September 25, 2017 included therein and the related prospectus supplement. The Company also issued to the Underwriter warrants to purchase up to 66,000 shares of the Company’s common stock, such issuance being exempt from registration pursuant to Section 4 (a)(2) of the Securities Act. Each Underwriter warrant is exercisable six months from the date of issuance, have an exercise price of $2.87 per whole share, and expire five years from the date first exercisable.

July 6, 2017 Common Stock Offering

On July 6, 2017, the Company entered into a securities purchase agreement with several investors, pursuant to which the Company agreed to issue and sell, in a registered direct offering, an aggregate of 2,050,000 shares of common stock of the Company at an offering price of $2.07 per share for gross proceeds of $4,243,500 before the deduction of the placement agent fee and offering expenses. In addition, the Company sold Pre-Funded Series CCC Warrants to purchase 385,000 shares of common stock (and the shares of common stock issuable upon exercise of the Pre-Funded Series CCC Warrants), in lieu of shares of common stock to the extent that the purchase of common stock would cause the beneficial ownership of the Purchaser, together with its affiliates and certain related parties, to exceed 9.99% of our common stock. The Pre-Funded Series CCC Warrants were sold at an offering price of $2.06 per share for gross proceeds of $793,100, are immediately exercisable for $0.01 per share of common stock and do not have an expiration date. In a concurrent private placement, the Company agreed to issue to each investor, for each share of common stock and pre-funded warrant purchased in the offering, a Series AAA Warrant and Series BBB Warrant, each to purchase one share of common stock. The Series AAA Warrants are initially exercisable six months following issuance and terminate five and one-half years following issuance. The Series AAA Warrants have an exercise price of $2.07 per share and are exercisable to purchase an aggregate of 2,435,000 shares of common stock. The Series BBB Warrants are immediately exercisable following issuance and terminate twelve months following issuance. The Series BBB Warrants have an exercise price of $4.75 per share and are exercisable to purchase an aggregate of 2,435,000 shares of common stock. Subject to limited exceptions, a holder of a Series AAA and Series BBB Warrant will not have the right to exercise any portion of its warrants if the holder, together with its affiliates, would beneficially own in excess of 9.99% of the number of shares of common stock outstanding immediately after giving effect to such exercise. During the fourth quarter of 2017, all 385,000 of the Series CCC Pre-Funded warrants were exercised in full.

On October 4, 2017, the Company entered into letter agreements (the “Exercise Agreements”) with the holders of the Series AAA and Series BBB Warrants issued in the July 6, 2017 Common Stock Offering (the “Exercising Holders”). The Exercise Agreements amended the Series AAA Warrants to permit their immediate exercise. Prior to the execution of the Exercise Agreements, the Series AAA Warrants were not exercisable until January 11, 2018. Pursuant to the Exercise Agreements, the Exercising Holders and the Company agreed that the Exercising Holders would exercise all of their Existing Warrants with respect to 4,665,000 shares of Common Stock underlying such Existing Warrants. The Series AAA Warrants and Series BBB Warrants were exercised at a price of $2.07 per share and $4.75 per share, respectively, which were their respective original exercise prices. The Company received approximately $16.6 million in gross proceeds from the sale of these warrants.

The Exercise Agreements amended the Series AAA Warrants to permit their immediate exercise. Prior to the execution of the Exercise Agreements, the Series AAA Warrants were not exercisable until January 11, 2018. Pursuant to the Exercise Agreements, the Exercising Holders and the Company agreed that the Exercising Holders would exercise all of their Existing Warrants with respect to 4,665,000 shares of Common Stock underlying such Existing Warrants. The Series AAA Warrants and Series BBB Warrants were exercised at a price of $2.07 per share and $4.75 per share, respectively, which were their respective original exercise prices. The Company received approximately $16.6 million in gross proceeds from the sale of these warrants.

The Exercise Agreements also provide for the issuance of 1,166,250 Series DDD Warrants, each to purchase one share of Common Stock (the “Series DDD Warrants”). The Series DDD Warrants have an exercise price $6.20, are exercisable one year following issuance and terminate six months after they are initially exercisable. The Series DDD Warrants and the shares of Common Stock issuable upon the exercise of the Series DDD Warrants were offered pursuant to the exemption provided in Section 4(a)(2) under the Securities Act or Rule 506(b) promulgated thereunder. Pursuant to the Exercise Agreements, the Series DDD Warrants shall be substantially in the form of the Existing Warrants and the Company will be required to register for resale the shares of Common Stock underlying the Series DDD Warrants.

February 14, 2017 Public Offering

On February 14, 2017, the Company entered into a securities purchase agreement whereby it sold, in a public offering (the “February 2017 Public Offering”), an aggregate of 1,384,704 shares of common stock of the Company at an offering price of $3.22 per share. In addition, the Company sold Series AA Warrants (the “Series AA Warrants”) to purchase up to 1,177,790 shares of common stock and Pre-Funded Series BB Warrants (the “Pre-Funded Series BB Warrants”) to purchase up to 185,713 shares of common stock. The Series AA Warrants have an exercise price of $3.22 per share, have a five-year life and are immediately exercisable. The Pre-Funded Series BB Warrants were offered at $3.08 per share, were immediately exercisable for $0.14 per share of common stock, do not have an expiration date and were issued in lieu of shares of common stock to the extent that the purchase of common stock would cause the beneficial ownership of the purchaser of such shares, together with its affiliates and certain related parties, to exceed 9.99% of our common stock. The Company received approximately $5.0 million in gross proceeds before the deduction of the placement agent fees and offering expenses (excluding any proceeds from the exercise of the warrants) in the February 2017 Public Offering.

Concurrently with the exchange agreements associated with the Investor Warrants discussed above on October 26, 2018, the Company and certain holders of the Series AA Warrants entered into Exchange Agreements whereby certain holders of the Series AA Warrants elected to surrender their Series AA Warrants, representing 321,428 shares of Common Stock collectively. In exchange for the surrender of their Series AA Warrants, these holders received 160,414 shares of Common Stock. Collectively the Company incurred broker and legal fees of approximately $0.1 million associated with the Exchange Agreements and recorded these as costs of equity financing and charged against additional paid-in capital.

In connection with the February 2017 Public Offering, the Company filed with the SEC a registration statement on Form S-1 (Registration No. 333-215321) on December 23, 2016, as amended by Pre-Effective Amendment No. 1 filed with the Commission on January 20, 2017, as further amended by Pre-Effective Amendment No. 2 filed with the Commission on February 13, 2017, as further amended by Pre-Effective Amendment No. 3 filed with the Commission on February 13, 2017 and as further amended by Pre-Effective Amendment No. 4 filed with the Commission on February 14, 2017 for the registration of the securities issued and sold under the Securities Act of 1933, as amended.

As of December 31, 2017, all 185,713 of the Series BB Pre-Funded warrants were exercised in full. During 2017, we received approximately $2.4 million from the exercise of Series AA Warrants to purchase 747,254 shares of common stock.

Reduced Exercise Price of Warrants

On February 22, 2013, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed, among other things, to issue warrants (the “2013 Warrants”) to purchase up to 95,811 shares of our common stock at an exercise price of $74.34 per share to such investors in a registered direct offering. On January 15, 2014, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed, among other things, to issue warrants (the “2014 Warrants”) to purchase up to 64,348 shares of our common stock at an exercise price of $57.40 per share to such investors in a registered direct offering. On June 9, 2017, the Company entered into warrant exercise agreements (the “Exercise Agreements”) with certain holders of the 2013 Warrants, the 2014 Warrants and the June 2016 Warrants (the “Exercising Holders”), which Exercising Holders own, in the aggregate, warrants exercisable for 790,410 shares of our common stock. Pursuant to the Exercise Agreements, the Exercising Holders and the Company agreed that the Exercising Holders would exercise their 2013 Warrants, the 2014 Warrants and the June 2016 Warrants with respect to 790,410 shares of our common stock underlying such warrants for a reduced exercise price equal to $2.70 per share. The Company received aggregate gross proceeds of approximately $2.1 million from the exercise of the 2013 Warrants, the 2014 Warrants and the June 2016 Warrants by the Exercising Holders.

The reduced exercise price of the 2013 Warrants, the 2014 Warrants and the June 2016 Series C Warrants increased the fair value of the warrants by approximately $0.2 million. This increase in fair value is recorded as a deemed dividend in additional paid in capital due to the retained deficit and it increased the net loss available to common shareholders on the consolidate statement of operations.

On May 27, 2015, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company agreed, among other things, to issue warrants (the “2015 Warrants”) to purchase up to 139,284 shares of the Company’s common stock at an exercise price of $36.40 per share, to such investors in a registered direct offering. Between June 22, 2017 through June 26, 2017, the Company and holders of the 2015 Warrants and the December 2016 Warrants (the “Exercising Investors”) entered into agreements whereby the Company agreed that the Exercising investors would exercise their 2015 Warrants and the June 2016 Warrants with respect to 506,627 shares of our common stock underlying such warrants for a reduced exercise price equal to $1.65 per share. The Company received aggregate gross proceeds of approximately $0.8 million from the exercise of the 2015 Warrants and the June 2016 Warrants by the Exercising Investors.

The reduced exercise price of the 2015 Warrants increased the fair value of the warrants by approximately $0.1 million. This increase in fair value is recorded as a deemed dividend in additional paid in capital due to the retained deficit and it increased the net loss available to common shareholders on the consolidate statement of operations.

Aspire Purchase Agreement

On August 31, 2018, we entered into a common stock purchase agreement (the “Aspire Purchase Agreement”) with Aspire Capital Fund, LLC (“Aspire Capital”) which provides that, upon the terms and subject to the conditions and limitations set forth therein, Aspire Capital is committed to purchase up to an aggregate of $15.0 million of shares of the Company’s common stock over the 24-month term of the Aspire Purchase Agreement. On October 12, 2018, the Company filed with the SEC a prospectus supplement to the 2018 Shelf Registration Statement registering all of the shares of common stock that may be offered to Aspire Capital from time to time.

Under the Aspire Purchase Agreement, on any trading day selected by the Company, the Company has the right, in its sole discretion, to present Aspire Capital with a purchase notice (each, a “Purchase Notice”), directing Aspire Capital (as principal) to purchase up to 100,000 shares of the Company’s common stock per business day, up to $15.0 million of the Company’s common stock in the aggregate at a per share price (the “Purchase Price”) equal to the lesser of:

	●	the lowest sale price of the Company’s common stock on the purchase date; or
	●	the arithmetic average of the three (3) lowest closing sale prices for the Company’s common stock during the ten (10) consecutive trading days ending on the trading day immediately preceding the purchase date.

The Company and Aspire Capital also may mutually agree to increase the number of shares that may be sold to as much as an additional 2,000,000 shares per business day.

In addition, on any date on which the Company submits a Purchase Notice to Aspire Capital in an amount equal to at least 100,000 shares, the Company also has the right, in its sole discretion, to present Aspire Capital with a volume-weighted average price purchase notice (each, a “VWAP Purchase Notice”) directing Aspire Capital to purchase an amount of stock equal to up to 30% of the aggregate shares of the Company’s common stock traded on its principal market on the next trading day (the “VWAP Purchase Date”), subject to a maximum number of shares the Company may determine. The purchase price per share pursuant to such VWAP Purchase Notice is generally 97% of the volume-weighted average price for the Company’s common stock traded on its principal market on the VWAP Purchase Date.

The Purchase Price will be adjusted for any reorganization, recapitalization, non-cash dividend, stock split, or other similar transaction occurring during the period(s) used to compute the Purchase Price. The Company may deliver multiple Purchase Notices and VWAP Purchase Notices to Aspire Capital from time to time during the term of the Purchase Agreement, so long as the most recent purchase has been completed.

There are no trading volume requirements or restrictions under the Purchase Agreement, and the Company will control the timing and amount of sales of the Company’s common stock to Aspire Capital. Aspire Capital has no right to require any sales by the Company but is obligated to make purchases from the Company as directed by the Company in accordance with the Purchase Agreement. There are no limitations on use of proceeds, financial or business covenants, restrictions on future funding, rights of first refusal, participation rights, penalties or liquidated damages in the Purchase Agreement. In consideration for entering into the Purchase Agreement, concurrently with the execution of the Purchase Agreement, the Company issued to Aspire Capital 164,835 shares of the Company’s common stock (the “Commitment Shares”). The Company’s policy is to record specific incremental costs directly attributable to an offering as a charge against the gross proceeds, if any, when the offering becomes effective. These Commitment Shares valued at $450,000 were recorded in September 2018 as costs of equity financing and charged against additional paid-in capital. The Aspire Purchase Agreement may be terminated by the Company at any time, at its discretion, without any cost to the Company. Aspire Capital has agreed that neither it nor any of its agents, representatives and affiliates shall engage in any direct or indirect short-selling or hedging of the Company’s common stock during any time prior to the termination of the Purchase Agreement. Any proceeds from the Company receives under the Aspire Purchase Agreement are expected to be used for working capital and general corporate purposes. During 2018 and as of December 31, 2018, the Company sold and issued an aggregate of 100,000 shares under the Purchase Agreement, receiving approximately $0.2 million. During 2019 and as of March 28, 2019, the Company sold and issued an aggregate of 600,000 shares under the Purchase Agreement, receiving approximately $1.3 million.

Capital on Demand^TM Sales Agreement

On December 4, 2018, the Company entered into a Capital on Demand^TM Sales Agreement (the “Capital on Demand Agreement”) with JonesTrading Institutional Services LLC, as sales agent (“JonesTrading”), pursuant to which the Company may offer and sell, from time to time, through JonesTrading shares of Common Stock having an aggregate offering price of up to $16.0 million. The Company intends to use the net proceeds from the offering, if any, for general corporate purposes, including research and development activities, capital expenditures and working capital.

The Company is not obligated to sell any Common Stock under the Capital on Demand Agreement and, subject to the terms and conditions of the Capital on Demand Agreement, JonesTrading will use commercially reasonable efforts, consistent with its normal trading and sales practices and applicable state and federal law, rules and regulations and the rules of The NASDAQ Capital Market, to sell Common Stock from time to time based upon Celsion’s instructions, including any price, time or size limits or other customary parameters or conditions the Company may impose. Under the Capital on Demand Agreement, JonesTrading may sell Common Stock by any method deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended.

The Capital on Demand Agreement will terminate upon the earlier of (i) the sale of all shares of our common stock subject to the Sales Agreement, and (ii) the termination of the Capital on Demand Agreement by JonesTrading or Celsion. The Capital on Demand Agreement may be terminated by JonesTrading or the Company at any time upon 10 days’ notice to the other party, or by JonesTrading at any time in certain circumstances, including the occurrence of a material adverse change in the Company.

The Company will pay JonesTrading a commission of 3.0% of the aggregate gross proceeds from each sale of Common Stock and has agreed to provide JonesTrading with customary indemnification and contribution rights.

The Shares will be issued pursuant to Celsion’s previously filed and effective Registration Statement on Form S-3 (File No. 333-227236), the base prospectus dated October 12, 2018, filed as part of such Registration Statement, and the prospectus supplement dated December 4, 2018, filed by Celsion with the Securities and Exchange Commission. The Company did not sell any shares under the Capital on Demand Agreement as of December 31, 2018. During 2019 and as of March 28, 2019, the Company sold and issued an aggregate of 122,186 shares under the Capital on Demand Agreement, receiving approximately $0.3 million.

Controlled Equity Offering

On February 1, 2013, the Company entered into a Controlled Equity Offering SM Sales Agreement (the “ATM Agreement”) with Cantor Fitzgerald & Co., as sales agent (“Cantor”), pursuant to which Celsion could offer and sell, from time to time, through Cantor, shares of our common stock having an aggregate offering price of up to $25.0 million (the “ATM Shares”) pursuant to the 2015 Shelf Registration Statement. Under the ATM Agreement, Cantor may sell ATM Shares by any method deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including sales made directly on The NASDAQ Capital Market, on any other existing trading market for our common stock or to or through a market maker. On October 10, 2018, the Company delivered notice to Cantor terminating the ATM effective as of October 20, 2018. The Company has no further obligations under the Sales Agreement. During 2018, the Company received approximately $1.2 million in proceeds from the sale of 457,070 shares of common stock under the ATM Agreement and during 2017, it received approximately $3.9 million in proceeds from the sale of 1,221,348 shares of common stock under the ATM Agreement. From February 1, 2013 through September 30, 2018, the Company sold and issued an aggregate of 1,784,396 shares of common stock under the ATM Agreement, receiving approximately $12.8 million in gross proceeds.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

11. STOCK-BASED COMPENSATION

The Company has long-term compensation plans that permit the granting of equity based-awards in the form of stock options, restricted stock, restricted stock units, stock appreciation rights, other stock awards, and performance awards.

At the 2018 Annual Stockholders Meeting of the Company held on May 15, 2018, stockholders approved the Celsion Corporation 2018 Stock Incentive Plan (the “2018 Plan”). The 2018 Plan, as adopted, permits the granting of 2,700,000 shares of Celsion common stock as equity awards in the form of incentive stock options, nonqualified stock options, restricted stock, restricted stock units, stock appreciation rights, other stock awards, performance awards, or in any combination of the foregoing. Prior to the adoption of the 2018 Plan, the Company had maintained the Celsion Corporation 2007 Stock Incentive Plan (the 2007 Plan). The 2007 Plan permitted the granting of 688,531 shares of Celsion common stock as equity awards in the form of incentive stock options, nonqualified stock options, restricted stock, restricted stock units, stock appreciation rights, phantom stock, performance awards, or in any combination of the foregoing. The 2018 Plan replaced the 2007 Plan although the 2007 Plan remains in effect for awards previously granted under the 2007 Plan. Under the terms of the 2018 Plan, any shares subject to an award under the 2007 Plan which are not delivered because of the expiration, forfeiture, termination or cash settlement of the award will become available for grant under the 2018 Plan.

The Company has issued stock awards to employees and directors in the form of stock options and restricted stock. Options are generally granted with strike prices equal to the fair market value of a share of Celsion common stock on the date of grant. Incentive stock options may be granted to purchase shares of common stock at a price not less than 100% of the fair market value of the underlying shares on the date of grant, provided that the exercise price of any incentive stock option granted to an eligible employee owning more than 10% of the outstanding stock of Celsion must be at least 110% of such fair market value on the date of grant. Only officers and key employees may receive incentive stock options.

Option and restricted stock awards vest upon terms determined by the Compensation Committee of the Board of Directors and are subject to accelerated vesting in the event of a change of control or certain terminations of employment. The Company issues new shares to satisfy its obligations from the exercise of options or the grant of restricted stock awards.

On September 28, 2018, the Compensation Committee of the Board of Directors approved the grant of (i) inducement stock options (the “Inducement Option Grants”) to purchase a total of 164,004 shares of Celsion common stock and (ii) inducement restricted stock awards (the “Inducement Stock Grants”) totaling 19,000 shares of Celsion common stock to three new employees. All awards have a grant date of September 28, 2018. Each of Inducement Option Grant has an exercise price per share equal to $2.77, the closing price of Celsion’s common stock as reported by Nasdaq on September 28, 2018. Each Inducement Option Grant will vest over three years, with one-third vesting on the one-year anniversary of the employee’s first day of employment with the Company and one-third vesting on the second and third anniversaries thereafter, subject to the new employee’s continued service relationship with the Company on each such date. Each Inducement Option Grant has a ten-year term and is subject to the terms and conditions of the applicable stock option agreement. Each of Inducement Stock Grant will vest on the one-year anniversary of the employee’s first day of employment with the Company and are subject to the new employee’s continued service relationship with the Company through such date and is subject to the terms and conditions of the applicable restricted stock agreement.

As of December 31, 2018, there were a total of 3,399,893 shares of Celsion common stock reserved for issuance under the 2018 Plan, which were comprised of 3,064,741 shares of Celsion common stock subject to equity awards previously granted under the 2018 Plan and 2007 Plan and 335,152 shares of Celsion common stock available for future issuance under the 2018 Plan. As of December 31, 2018, there were a total of 106,502 of Celsion common stock subject to outstanding inducement awards.

Total compensation cost charged related to stock options and restricted stock awards amounted to $4.6 million and $1.1 million during 2018 and 2017, respectively as was recognized in operating expenses. As of December 31, 2018, there was $1.8 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements. That cost is expected to be recognized over a weighted-average period of 0.9 years. The weighted average grant date fair values of the stock options granted during 2018 and 2017 was $2.36 and 2.32, respectively.

A summary of stock option awards as of December 31, 2018 and changes during the two-year period ended December 31, 2018 is presented below:

Stock Options	Number Outstanding			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at January 1, 2017		211,213		$	61.59
Granted		535,964		$	2.69
Canceled or expired		(43,735	)	$	164.12
Outstanding at December 31, 2017		703,442		$	10.34
Granted		2,629,004		$	2.26
Canceled or expired		(183,703	)	$	25.96
Outstanding at December 31, 2018		3,148,743		$	2.67		9.2	$	-

Exercisable at December 31, 2018		1,689,902		$	2.97		9.1	$	-

A summary of the status of the Company’s non-vested restricted stock awards as of December 31, 2018 and changes during the two year period ended December 31, 2018, is presented below:

Restricted Stock	Number Outstanding			Weighted Average Grant Date Fair Value
Non-vested stock awards outstanding at January 1, 2017		4,785		$	37.42
Granted		(3,357	)	$	42.20
Vested and issued		(1,428	)	$	26.18
Non-vested stock awards outstanding at December 31, 2017		-		$	-
Granted		35,000		$	2.71
Vested and issued		(6,000	)	$	2.77
Forfeited		(6,500	)	$	2.64
Non-vested stock awards outstanding at December 31, 2018		22,500		$	2.72

A summary of stock options outstanding at December 31, 2018 by price range is as follows:

	Options Outstanding					Options Exercisable

Range of Exercise Prices		Number	Weighted Average Remaining Contractual Term (in years)		Weighted Average Exercise Price		Number	Weighted Average Remaining Contractual Term (in years)		Weighted Average Exercise Price

Up to $5.00		3,084,252	9.2	$	2.34		1,625,807	9.2	$	2.34
Above $5.00 to $81.90		64,491	7.0	$	19.00		64,095	7.0	$	19.00
		3,148,743					1,689,902

The fair values of stock options granted were estimated at the date of grant using the Black-Scholes option pricing model. The Black-Scholes model was originally developed for use in estimating the fair value of traded options, which have different characteristics from Celsion’s stock options. The model is also sensitive to changes in assumptions, which can materially affect the fair value estimate. The Company used the following assumptions for determining the fair value of options granted under the Black-Scholes option pricing model:

	Year Ended December 31,
	2018			2017
Risk-free interest rate		2.82 to 3.02	%		2.21 to 2.32	%
Expected volatility		99.9 - 102.12	%		90.4 - 100.8	%
Expected life (in years)		8.5 to 10			10
Expected dividend yield		0.0	%		0.0	%

Expected volatilities utilized in the model are based on historical volatility of the Company’s stock price. Starting in 2017, the Company made the election to account for forfeitures when they occur.

Earn-out Milestone Liability

12 Months Ended

Dec. 31, 2018

Earn-out Milestone Liability

Earn-out Milestone Liability

12. EARN-OUT MILESTONE LIABILITY

The total aggregate purchase price for the EGEN Acquisition included potential future Earn-out Payments contingent upon achievement of certain milestones. The difference between the aggregate $30.4 million in future Earn-out Payments and the $13.9 million included in the fair value of the acquisition consideration at June 20, 2014 was based on the Company’s risk-adjusted assessment of each milestone (10% to 67%) and utilizing a discount rate based on the estimated time to achieve the milestone (1.5 to 2.5 years). The earn-out milestone liability will be fair valued at the end of each quarter and any change in their value will be recognized in the financial statements.

At December 31, 2018, the Company fair valued the earn-out milestone liability at $8.9 million and recognized a non-cash gain of $3.6 million during 2018 as a result of the change in the fair value of earn-out milestone liability of $12.5 million at December 31, 2017. Included in the non-cash gain during 2018, was the reduction of the liability by $3.9 million during the third quarter of 2017 related to the write down of one of the in-process research and development assets (see Note 5) as the Company believes there is a de minimis probability of the payout of the related earn-out milestone liabilities. The fair value of the remaining earn-out milestone liabilities at December 31, 2018 was based on the Company’s risk-adjusted assessment of each milestone (80%) utilizing a discount rate based on the estimated time to achieve the milestone (1.25 years).

At December 31, 2017, the Company fair valued the earn-out milestone liability at $12.5 million and recognized a non-cash gain of $0.6 million during 2017 as a result of the change in the fair value of earn-out milestone liability of $13.2 million at December 31, 2016. The non-cash gain during 2017 resulted from the reduction of the liability by $1.4 million during the third quarter of 2017 related to the partial write down of one of the in-process research and development assets (see Note 5) as the Company believes there is a reduced probability of the payout of the related earn-out milestone liabilities. The fair value of the remaining earn-out milestone liabilities at December 31, 2017 was based on the Company’s risk-adjusted assessment of each milestone (50% to 80%) utilizing a discount rate based on the estimated time to achieve the milestone (1.3 to 1.5 years).

The following is a summary of the changes in the earn-out milestone liability for 2017 and 2018:

Balance at January 1, 2017	$	13,188,226
Non-cash gain from the adjustment for the change in fair value included in 2017 net loss		(649,701	)
Balance at December 31, 2017		12,538,525
Non-cash gain from the adjustment for the change in fair value included in 2018 net loss		(3,630,861	)
Balance at December 31, 2018	$	8,907,664

Warrants

12 Months Ended

Dec. 31, 2018

Notes To Financial Statements [Abstract]

Warrants

13. WARRANTS

As more fully described in Notes 8 and 10, the Company completed a series of equity and debt financing transactions in 2018 and 2017 that included the issuance of warrants to purchase 190,114 and 9,231,628 shares, respectively, of the Company’s common stock. During 2018, the Company and certain investors holding warrants to collectively purchase 1.6 million shares of the Company’s common stock, which were received in the February 2017 Public Offering and the October 2017 Underwritten Offering, entered into warrant exchange agreements whereby the Company issued 820,714 shares of its common stock in exchange for the cancellation of the warrants. Investors exercised warrants to purchase 7,617,148 shares of common stock providing $22.0 million in gross proceeds to the Company during 2017. Warrants to purchase 13,927 and 44,037 shares of common stock expired during 2018 and 2017, respectively. After the warrant exchange, warrants outstanding totaled approximately 1.6 million with a weighted average exercise price of $5.75 per share as of December 31, 2018. Approximately 1.2 million of these outstanding warrants with a strike price of $6.20 per share will expire on April 4, 2019.

Following is a summary of all warrant activity for the two years ended December 31, 2018:

Warrants	Number of Warrants Issued			Weighted Average Exercise Price
Warrants outstanding at January 1, 2017		1,487,958		$	9.39
Warrants issued in connection with 2017 equity transactions		9,231,628		$	3.46
Warrants exercised during 2017		(7,617,147	)	$	2.89
Warrants expired during 2017		(44,037	)	$	209.23
Warrants outstanding at December 31, 2017		3,058,402		$	5.29
Warrants issued in connection with 2018 debt transaction		190,114		$	2.63
Warrants cancelled in exchange for common stock		(1,641,427	)	$	3.04
Warrants expired during 2018		(13,927	)	$	226.24
Warrants outstanding and exercisable at December 31, 2018		1,593,162		$	5.36

Aggregate intrinsic value of outstanding warrants at December 31, 2018	$	-

Weighted average remaining contractual terms (years)		1.87

Celsion Employee Benefit Plans

12 Months Ended

Dec. 31, 2018

Defined Benefit Plan [Abstract]

Celsion Employee Benefit Plans

14. CELSION EMPLOYEE BENEFIT PLANS

Celsion maintains a defined-contribution plan under Section 401(k) of the Internal Revenue Code. The plan covers substantially all employees over the age of 21. Participating employees may defer a portion of their pretax earnings, up to the IRS annual contribution limit. The Company makes a matching contribution up to a maximum of 3% of an employee’s annual salary. The Company’s total matching contributions for the years ended December 31, 2018 and 2017 was $93,948 and $77,352 respectively. During 2018 and 2017, the Company also provided a discretionary contribution totaling $181,999 and $172,497, respectively, which represented 6% of each eligible participant’s annual salary in each of 2018 and 2017. These amounts were paid in January in each of the subsequent years.

Licenses of Intellectual Property and Patents

12 Months Ended

Dec. 31, 2018

Intangible Assets, Net (Including Goodwill) [Abstract]

Licenses of Intellectual Property and Patents

15. LICENSES OF INTELLECTUAL PROPERTY AND PATENTS

On November 10, 1999, the Company entered into a license agreement with Duke University (“Duke”) under which the Company received worldwide exclusive rights (subject to certain exceptions) to commercialize and use Duke’s thermally sensitive liposome technology. The license agreement contains annual royalty and minimum payment provisions due on net sales. The agreement also required milestone-based royalty payments measured by various events, including product development stages, FDA applications and approvals, foreign marketing approvals and achievement of significant sales. However, in lieu of such milestone-based cash payments, Duke agreed to accept shares of the Company’s common stock to be issued in installments at the time each milestone payment is due, with each installment of shares to be calculated at the average closing price of the common stock during the 20 trading days prior to issuance.

The total number of shares issuable to Duke under these provisions is subject to adjustment in certain cases, and Duke has piggyback registration rights for public offerings taking place more than one year after the effective date of the license agreement. On January 31, 2003, the Company issued 253,691 shares of common stock to Duke University valued at $2.2 million as payment for milestone-based royalties under this license agreement. An amendment to the Duke license agreement contains certain development and regulatory milestones, and other performance requirements that the Company has met with respect to the use of the licensed technologies. The Company will be obligated to make royalty payments based on sales to Duke upon commercialization, until the last of the Duke patents expire. For the years ended December 31, 2018 and 2017, the Company has not incurred any expense under this agreement and will not incur any future liabilities until commercial sales commence.

Under the November 1999 license agreement with Duke, the Company has rights to the thermally sensitive liposome technology, including Duke’s U.S. patents covering the technology as well as all foreign counter parts and related pending applications. Foreign counterpart applications have been issued in the EU, Hong Kong, Australia and Canada and have been allowed in Japan. The EU patent has been validated in Austria, Belgium, France, Germany, Great Britain, Italy, Luxembourg, Monaco, Spain and Switzerland. In addition, the Duke license agreement provides the Company with rights to multiple issued and pending U.S. patents related to the formulation, method of making and use of heat sensitive liposomes. The Company’s rights under the license agreement with Duke extend for the life of the last-to-expire of the licensed patents.

The Company has licensed from Valentis, CA certain global rights covering the use of pegylation for temperature sensitive liposomes.

In addition to the rights available to the Company under completed or pending license agreements, the Company is actively pursuing patent protection for technologies developed by the Company. Among these patents is a family of pending US and international patent applications which seek to protect the Company’s proprietary method of storing ThermoDox® which is critical for worldwide distribution channels.

ThermoDox® is a registered trademark in the U.S., Argentina, Australia, Canada, China, Columbia, the EU Member States: (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Korea, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, the United Kingdom), Hong Kong, Israel, Japan, New Zealand, Peru, Philippines, Russia, Singapore, South Korea and Taiwan. The Company has registered transliterations of ThermoDox® in China, Hong Kong, Japan, Singapore, South Korea and Taiwan. The Company has an additional 14 trademark protection applications pending for ThermoDox® in countries world-wide.

Finally, through proprietary information agreements with employees, consultants and others, the Company seeks to protect its own proprietary know-how and trade secrets. The Company cannot offer assurances that these confidentiality agreements will not be breached, that the Company will have adequate remedies for any breach, or that these agreements, even if fully enforced, will be adequate to prevent third-party use of the Company’s proprietary technology. Similarly, the Company cannot guarantee that technology rights licensed to it by others will not be successfully challenged or circumvented by third parties, or that the rights granted will provide the Company with adequate protection.

Technology Development and Licensing Agreements

12 Months Ended

Dec. 31, 2018

Technology Development And Licensing Agreements

Technology Development and Licensing Agreements

16. TECHNOLOGY DEVELOPMENT AND LICENSING AGREEMENTS

On May 7, 2012, the Company entered into a long-term commercial supply agreement with Zhejiang Hisun Pharmaceutical Co. Ltd. (Hisun) for the production of ThermoDox® in the China territory. In accordance with the terms of the agreement, Hisun will be responsible for providing all of the technical and regulatory support services, including the costs of all technical transfer, registration and bioequivalence studies, technical transfer costs, Celsion consultative support costs and the purchase of any necessary equipment and additional facility costs necessary to support capacity requirements for the manufacture of ThermoDox®. Celsion will repay Hisun for the aggregate amount of these development costs and fees commencing on the successful completion of three registration batches of ThermoDox®. Hisun is also obligated to certain performance requirements under the agreement. The agreement will initially be limited to a percentage of the production requirements of ThermoDox® in the China territory with Hisun retaining an option for additional global supply after local regulatory approval in the China territory. In addition, Hisun will collaborate with Celsion around the regulatory approval activities for ThermoDox® with the China State Food and Drug Administration (CHINA FDA). During the first quarter of 2015, Hisun completed the successful manufacture of three registration batches of ThermoDox®.

On January 18, 2013, we entered into a technology development contract with Hisun, pursuant to which Hisun paid us a non-refundable research and development fee of $5 million to support our development of ThermoDox ^® in mainland China, Hong Kong and Macau (the China territory). Following our announcement on January 31, 2013 that the HEAT study failed to meet its primary endpoint, Celsion and Hisun have agreed that the Technology Development Contract entered into on January 18, 2013 will remain in effect while the parties continue to collaborate and are evaluating the next steps in relation to ThermoDox ^® , which include the sub-group analysis of patients in the Phase III HEAT Study for the hepatocellular carcinoma clinical indication and other activities to further the development of ThermoDox ^® for the Greater China market. The $5.0 million received as a non-refundable payment from Hisun in the first quarter 2013 has been recorded to deferred revenue and will continue to be amortized over the 10 -year term of the agreement, until such time as the parties find a mutually acceptable path forward on the development of ThermoDox ^® based on findings of the ongoing post-study analysis of the HEAT Study data.

On July 19, 2013, the Company and Hisun entered into a Memorandum of Understanding to pursue ongoing cooperation for the continued clinical development of ThermoDox® as well as the technology transfer relating to the commercial manufacture of ThermoDox® for the China territory. This expanded level of cooperation includes development of the next generation liposomal formulation with the goal of creating safer, more efficacious versions of marketed cancer chemotherapeutics.

Among the key provisions of the Celsion-Hisun Memorandum of Understanding are:

	●	Hisun will provide the Company with internal resources necessary to complete the technology transfer of the Company’s proprietary manufacturing process and the production of registration batches for the China territory;

	●	Hisun will coordinate with the Company around the clinical and regulatory approval activities for ThermoDox® as well as other liposomal formations with the CHINA FDA; and

	●	Hisun will be granted a right of first offer for a commercial license to ThermoDox® for the sale and distribution of ThermoDox® in the China territory.

On August 8, 2016, we signed a Technology Transfer, Manufacturing and Commercial Supply Agreement (“GEN-1 Agreement”) with Hisun to pursue an expanded partnership for the technology transfer relating to the clinical and commercial manufacture and supply of GEN- 1, Celsion’s proprietary gene mediated, IL- 12 immunotherapy, for the greater China territory, with the option to expand into other countries in the rest of the world after all necessary regulatory approvals are in effect. The GEN- 1 Agreement will help to support supply for both ongoing and planned clinical studies in the U.S., and for potential future studies of GEN- 1 in China. GEN- 1 is currently being evaluated by Celsion in first line ovarian cancer patients.

Key provisions of the GEN-1 Agreement are as follows:

	●	the GEN-1 Agreement has targeted unit costs for clinical supplies of GEN-1 that are substantially competitive with the Company’s current suppliers;

	●	once approved, the cost structure for GEN-1 will support rapid market adoption and significant gross margins across global markets;

	●	Celsion will provide Hisun a certain percentage of China’s commercial unit demand, and separately of global commercial unit demand, subject to regulatory approval;

	●	Hisun and Celsion will commence technology transfer activities relating to the manufacture of GEN-1, including all studies required by CFDA for site approval; and

	●	Hisun will collaborate with Celsion around the regulatory approval activities for GEN-1 with the CFDA. A local China partner affords Celsion access to accelerated CFDA review and potential regulatory exclusivity for the approved indication.

The Company evaluated the Hisun arrangement in accordance with ASC 606 and determined that its performance obligations under the agreement include the non-exclusive, royalty-free license, research and development services to be provided by the Company, and its obligation to serve on a joint committee. The Company concluded that the license was not distinct since its value is closely tied to the ongoing research and development activities. As such, the license and the research and development services are be bundled as a single performance obligation. Since the provision of the license and research and development services are considered a single performance obligation, the $5,000,000 upfront payment is being recognized as revenue ratably through 2022.

Commitments

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments

17. COMMITMENTS

In July 2011, the Company executed a lease (the “Lease”) with Brandywine Operating Partnership, L.P. (Brandywine), a Delaware limited partnership for a 10,870 square foot premises located in Lawrenceville, New Jersey. In October 2011, the Company relocated its offices to Lawrenceville, New Jersey from Columbia, Maryland. The lease has a term of 66 months and provides for 6 months of rent free, with the first monthly rent payment of approximately $23,000 due and paid in April 2012. Also, as required by the Lease, the Company provided Brandywine with an irrevocable and unconditional standby letter of credit for $250,000, which the Company secured with an escrow deposit at its banking institution of this same amount. The standby letter of credit was reduced by $50,000 on each of the 19th, 31st and 43rd months from the initial term, and the remaining $100,000 amount was reduced when the Lease term expired in April 2017. In late 2015, Lenox Drive Office Park LLC, purchased the real estate and office building and assumed the lease. This lease was set to expire on April 30, 2017. In April 2017, the Company and the landlord amended the Lease effective May 1, 2017. The Lease amendment extended the term of the agreement for an additional 64 months, reduced the premises to 7,565 square feet, reduced the monthly rent and provided four months free rent. On February 1, 2019, we amended the current terms of the lease to increase the size of the premises by 2,285 square feet to 9,850 square feet and also extended the lease term by one year to September 1, 2023. In conjunction with the February 1, 2019 lease amendment, we agreed to modify our one-time option to cancel the lease as of the 36th month after the May 1, 2017 lease commencement date. The monthly rent will range from approximately $18,900 in the first year to approximately $20,500 in the final year of the amendment. The Company also has a one-time option to cancel the lease as of the 24th month after the commencement date of the Lease amendment.

In connection with the EGEN Asset Purchase Agreement in June 2014, the Company assumed the existing lease with another landlord for an 11,500 square foot premises located in Huntsville Alabama. This lease has a remaining term of one month with rent a payment of approximately $23,200 per month. In January 2018, the Company and this landlord entered into a new 60 -month lease which reduced the premises to 9,049 square feet with rent payments of approximately $18,100 per month.

The Company paid $457,321 and $502,716 in connection with these leases in 2018 and 2017, respectively. Following is a summary of the future minimum payments required under leases that have initial or remaining lease terms of one year or more as of December 31, 2018:

For the year ending December 31:	Operating Leases

2019	$	450,430
2020		454,213
2021		457,995
2022		379,823
		18,098
Total minimum lease payments	$	1,760,559

Subsequent Events

12 Months Ended

Dec. 31, 2018

Subsequent Events [Abstract]

Subsequent Events

18. SUBSEQUENT EVENTS

On March 28, 2019, the Company and EGWU, Inc, entered into an amendment to the Asset Purchase Agreement discussed in Note 5 (the “Amended Asset Purchase Agreement”). Pursuant to the Amended Asset Purchase Agreement, payment of the earnout milestone liability related to the Ovarian Cancer Indication of $12.4 million has been modified. The Company has the option to make the payment as follows:

	a)	$7.0 million in cash within 10 business days of achieving the milestone; or

	b)	$12.4 million in cash, common stock of the Company, or a combination of either, within one year of achieving the milestone.

The Company will provide EGWU, Inc. 200,000 warrants to purchase common stock at a strike price of $0.01 per warrant share as consideration for entering into this agreement. The Company will record this transaction in the first quarter of 2019.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Description of Business

Description of Business

Basis of Presentation

Basis of Presentation

Use of Estimates

Use of Estimates

Revenue Recognition

Revenue Recognition

Cash and Cash Equivalents

Cash and Cash Equivalents

Cash and cash equivalents include cash on hand and investments purchased with an original maturity of three months or less. A portion of these funds are not covered by FDIC insurance.

Fair Value of Investment Securities

Fair Value of Investment Securities

The carrying values of investment securities approximate their respective fair values.

Short Term Investments

Short Term Investments

Property and Equipment

Property and Equipment

Deposits

Deposits

Deposits include real property security deposits and other deposits which are contractually required and of a long-term nature.

In-Process Research and Development, Other Intangible Assets and Goodwill

In-Process Research and Development, Other Intangible Assets and Goodwill

Impairment or Disposal of Long-Lived Assets

Impairment or Disposal of Long-Lived Assets

Comprehensive Income (Loss)

Comprehensive Income (Loss)

Research and Development

Research and Development

Net Loss Per Common Share

Net Loss Per Common Share

Income Taxes

Income Taxes

Stock-Based Compensation

Stock-Based Compensation

Recent Accounting Pronouncements

Recent Accounting Pronouncements

	●	ASU No. 2018-10, Codification Improvements to Topic 842, Leases, which amends certain narrow aspects of the guidance issued in ASU 2016-02; and

	●	ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which allows for a transition approach to initially apply ASU 2016-02 at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption as well as an additional practical expedient for lessors to not separate non-lease components from the associated lease component.

Short Term Investments Available for Sale (Tables)

12 Months Ended

Dec. 31, 2018

Short-term Investments [Abstract]

Schedule of Cost, Fair Value and Maturities of Short Term Investments

A summary of the cost, fair value and maturities of the Company’s short-term investments is as follows:

	December 31, 2018				December 31, 2017
	Cost		Fair Value		Cost		Fair Value
Short-term investments
Corporate debt securities	$	14,228,126	$	14,257,998	$	12,734,184	$	12,724,020
Total	$	14,228,126	$	14,257,998	$	12,734,184	$	12,724,020

	December 31, 2018				December 31, 2017
	Cost		Fair Value		Cost		Fair Value
Short-term investment maturities
Within 3 months	$	5,383,488	$	5,393,743	$	-	$	-
Between 3-12 months		8,844,638		8,864,255		12,734,184		12,724,020
Total	$	14,228,126	$	14,257,998	$	12,734,184	$	12,724,020

Summary of Investment Securities Gross Unrealized Gains (losses)

The Company has reviewed individual securities to determine whether a decline in fair value below the amortizable cost basis is other than temporary.

	December 31, 2018					December 31, 2017
Available for sale securities (all unrealized holding gains and losses are less than 12 months at date of measurement)	Fair Value		Unrealized Holding Gains (Losses)			Fair Value		Unrealized Holding Gains (Losses)

Investments with unrealized gains	$	7,515,676	$	38,068		$	748,148	$	570
Investments with unrealized losses		6,742,322		(8,196	)		11,975,872		(10,734	)
Total	$	14,257,998	$	29,872		$	12,724,020	$	(10,164	)

Summary of Net Realized Losses On Sales of Available for Sale Securities and Investment Income Interest and Dividends

Investment income, which includes net realized losses on sales of available for sale securities and investment income interest and dividends, is summarized as follows:

	2018			2017
Interest and dividends accrued and paid	$	331,780		$	26,041
Accretion of investment discounts and premiums, net		32,066			-
Losses investment maturity and sales, net		(10,164	)		-
Investment income net	$	353,682		$	26,041

Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and liabilities measured at fair value are summarized below:

	Total Fair Value		Quoted Prices In Active Markets For Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:

Recurring items as of December 31, 2018
Corporate debt securities, available for sale	$	14,257,998	$	─	$	14,257,998	$	─

Recurring items as of December 31, 2017
Corporate debt securities, available for sale	$	12,724,020	$	─	$	12,724,020	$	─

Liabilities:

Recurring items as of December 31, 2018
Earn-out milestone liability (Note 12)	$	8,907,664	$	─	$	─	$	8,907,664

Non-recurring items as of December 31, 2018
In process R&D (Note 5)	$	15,736,491	$	─	$	─	$	15,736,491

Recurring items as of December 31, 2017
Earn-out milestone liability (Note 12)	$	12,538,525	$	─	$	─	$	12,538,525

Non-recurring items as of December 31, 2017
In process R&D (Note 5)	$	20,246,491	$	─	$	─	$	20,246,491

Acquisition of EGEN, Inc. (Tables)

12 Months Ended

Dec. 31, 2018

Business Combinations [Abstract]

Schedule of Fair Value of Assets Acquired and Liabilities Assumed

The following table summarizes the fair values of these assets acquired and liabilities assumed related to the acquisition.

Property and equipment, net	$	35,000
In-process research and development		24,211,000
Other Intangible assets (Covenant not to compete)		1,591,000
Goodwill		1,976,000
Total assets:		27,813,000
Accounts payable and accrued liabilities		(235,000	)
Net assets acquired	$	27,578,000

Schedule of Future Amortization Amounts During the Remaining Life

Following is a schedule of future amortization amounts during the remaining life of the Covenant Not to Compete.

	Year Ended December 31,
2019	$	227,316
2020		227,316
2021		113,660
Total	$	568,292

Schedule of Fair Value of Assets Acquired

Following is a summary of the net fair value of the assets acquired in the EGEN acquisition for the two years ended December 31, 2018:

	IPR&D			Goodwill		Covenant Not To Compete

Balance at January 1, 2017, net	$	22,766,491		$	1,976,101		1,022,924
Amortization		-			-		(227,316	)
Impairment charge		(2,520,000	)		-		-
Balance at December 31, 2017, net		20,246,491			1,976,101		795,608
Amortization		-			-		(227,316	)
Impairment charge		(4,510,000	)		-		-
Balance at December 31, 2018, net		15,736,491			1,976,101		568,292

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Summary of Property and Equipment

	Year Ended December 31,
	2018			2017
Machinery and equipment (5-7 year life)	$	2,596,170		$	2,495,959
Furniture and fixtures (3-5 year life)		267,712			248,709
Leasehold improvements (5-7 year life)		289,004			269,819
		3,152,886			3,014,487
Less accumulated depreciation and amortization		(2,968,259	)		(2,838,716	)
Total	$	184,627		$	175,771

Other Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2018

Payables and Accruals [Abstract]

Schedule of Other Accrued Liabilities

Other accrued liabilities at December 31, 2018 and 2017 include the following:

	Year Ended December 31,
	2018		2017
Amounts due to contract research organizations and other contractual agreements	$	749,369	$	665,373
Accrued payroll and related benefits		1,592,590		1,258,265
Accrued professional fees		198,654		264,668
Other		45,285		94,521
Total	$	2,585,898	$	2,282,827

Note Payable (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of Future Principle Payments, Net of Unamortized Debt Discounts

Following is a schedule of future principle payments, net of unamortized debt discounts and amortized end of term charges, due on the Horizon Credit Agreement:

	For the year ending December 31,
2019	$	-
2020		-
2021		4,583,333
2022		5,000,000
2023 and thereafter		416,667
Subtotal of future principle payments		10,000,000
Unamortized debt issuance costs, net		(582,963	)
Total	$	9,417,037

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Income Tax Provision (Benefit)

The income tax provision (benefit) for the years ended December 31, 2018 and 2017 consists of the following:

	2018			2017
Federal
Current	$	-		$	-
Deferred		-			-
State and Local		-			-
Current		(10,419,000	)		-
Deferred		-			-
Effective tax rate	$	(10,419,000	)		-

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the Company’s statutory tax rate to the effective rate for the years ended December 31, 2018 and 2017 is as follows:

	2018			2017
Federal statutory rate		21.0	%		21.0	%
State taxes, net of federal tax benefit		36.9			6.6
Permanent differences		(3.8	)		-
Other		(9.4	)		-
Change in valuation allowance and deferred rate change, net		2.0			(27.6	)
Effective tax rate		46.7	%		-	%

Schedule of Deferred Tax Assets and Liabilities

The components of the Company’s deferred tax asset as of December 31, 2018 and 2017 are as follows:

	December 31,
	2018			2017
Net operating loss carryforwards	$	51,498,000		$	62,216,000
Other Deferred tax assets, net		1,092,000			2,415,000
Subtotal		52,590,000			64,631,000
Valuation allowance		(52,590,000	)		(64,631,000	)
Total deferred tax asset	$	-		$	-

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock Option Awards

A summary of stock option awards as of December 31, 2018 and changes during the two-year period ended December 31, 2018 is presented below:

Stock Options	Number Outstanding			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at January 1, 2017		211,213		$	61.59
Granted		535,964		$	2.69
Canceled or expired		(43,735	)	$	164.12
Outstanding at December 31, 2017		703,442		$	10.34
Granted		2,629,004		$	2.26
Canceled or expired		(183,703	)	$	25.96
Outstanding at December 31, 2018		3,148,743		$	2.67		9.2	$	-

Exercisable at December 31, 2018		1,689,902		$	2.97		9.1	$	-

Summary of Non-vested Restricted Stock Awards

A summary of the status of the Company’s non-vested restricted stock awards as of December 31, 2018 and changes during the two year period ended December 31, 2018, is presented below:

Restricted Stock	Number Outstanding			Weighted Average Grant Date Fair Value
Non-vested stock awards outstanding at January 1, 2017		4,785		$	37.42
Granted		(3,357	)	$	42.20
Vested and issued		(1,428	)	$	26.18
Non-vested stock awards outstanding at December 31, 2017		-		$	-
Granted		35,000		$	2.71
Vested and issued		(6,000	)	$	2.77
Forfeited		(6,500	)	$	2.64
Non-vested stock awards outstanding at December 31, 2018		22,500		$	2.72

Summary of Stock Options Outstanding

A summary of stock options outstanding at December 31, 2018 by price range is as follows:

	Options Outstanding					Options Exercisable

Range of Exercise Prices		Number	Weighted Average Remaining Contractual Term (in years)		Weighted Average Exercise Price		Number	Weighted Average Remaining Contractual Term (in years)		Weighted Average Exercise Price

Up to $5.00		3,084,252	9.2	$	2.34		1,625,807	9.2	$	2.34
Above $5.00 to $81.90		64,491	7.0	$	19.00		64,095	7.0	$	19.00
		3,148,743					1,689,902

Schedule of Assumptions Used to Determine Fair Value of Options Granted

The model is also sensitive to changes in assumptions, which can materially affect the fair value estimate. The Company used the following assumptions for determining the fair value of options granted under the Black-Scholes option pricing model:

	Year Ended December 31,
	2018			2017
Risk-free interest rate		2.82 to 3.02	%		2.21 to 2.32	%
Expected volatility		99.9 - 102.12	%		90.4 - 100.8	%
Expected life (in years)		8.5 to 10			10
Expected dividend yield		0.0	%		0.0	%

Earn-out Milestone Liability (Tables)

12 Months Ended

Dec. 31, 2018

Earn-out Milestone Liability

Schedule of Changes in Earn-out Milestone Liability

The following is a summary of the changes in the earn-out milestone liability for 2017 and 2018:

Balance at January 1, 2017	$	13,188,226
Non-cash gain from the adjustment for the change in fair value included in 2017 net loss		(649,701	)
Balance at December 31, 2017		12,538,525
Non-cash gain from the adjustment for the change in fair value included in 2018 net loss		(3,630,861	)
Balance at December 31, 2018	$	8,907,664

Warrants (Tables)

12 Months Ended

Dec. 31, 2018

Notes To Financial Statements [Abstract]

Summary of Warrant Activity

Following is a summary of all warrant activity for the two years ended December 31, 2018:

Warrants	Number of Warrants Issued			Weighted Average Exercise Price
Warrants outstanding at January 1, 2017		1,487,958		$	9.39
Warrants issued in connection with 2017 equity transactions		9,231,628		$	3.46
Warrants exercised during 2017		(7,617,147	)	$	2.89
Warrants expired during 2017		(44,037	)	$	209.23
Warrants outstanding at December 31, 2017		3,058,402		$	5.29
Warrants issued in connection with 2018 debt transaction		190,114		$	2.63
Warrants cancelled in exchange for common stock		(1,641,427	)	$	3.04
Warrants expired during 2018		(13,927	)	$	226.24
Warrants outstanding and exercisable at December 31, 2018		1,593,162		$	5.36

Aggregate intrinsic value of outstanding warrants at December 31, 2018	$	-

Weighted average remaining contractual terms (years)		1.87

Commitments (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases

Following is a summary of the future minimum payments required under leases that have initial or remaining lease terms of one year or more as of December 31, 2018:

For the year ending December 31:	Operating Leases

2019	$	450,430
2020		454,213
2021		457,995
2022		379,823
		18,098
Total minimum lease payments	$	1,760,559

Summary of Significant Accounting Policies (Details Narrative) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts receivable
Contract liabilities	5,000,000
Depreciation	$ 130,000	$ 326,000
Number of shares of common stock issuable upon exercise of warrants and equity awards	4,764,405	3,761,844
Right-of-use assets	$ 1,100,000
Related lease liabilities	1,300,000
New Jersey [Member]
Tax benefits of EDA	11,100,000
Net proceeds from sale of net operating losses	$ 10,400,000
Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life	7 years
Hisun Agreement [Member]
Contract liabilities	$ 1,500,000	$ 2,000,000

Financial Condition (Details Narrative) - USD ($)	6 Months Ended	12 Months Ended
Financial Condition (Details Narrative) - USD ($)	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Cumulated net losses		$ (273,665,247)	$ (261,781,888)
Cash, investment securities and interest receivable		27,700,000
Common Stock Sales Agreement [Member] \| Aspire Capital Fund, LLC [Member]
Proceeds from available future sale of equity under common stock purchase agreement		31,000,000
New Jersey [Member]
Tax benefits of EDA		11,100,000
New Jersey [Member] \| Maximum [Member]
Tax benefits of EDA	$ (12,500,000)
New Jersey [Member]
Tax benefits of EDA		11,100,000
Unrecognized tax benefits		$ 3,900,000

Short Term Investments Available for Sale (Details Narrative) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Short-term investments - Fair Value	$ 14,257,998	$ 12,724,020
Corporate Debt Securities [Member]
Short-term investments - Fair Value	14,257,998	12,724,020
Short-term Investments [Member] \| Corporate Debt Securities [Member]
Short-term investments - Fair Value	$ 14,257,998	$ 12,724,020

Short Term Investments Available for Sale - Schedule of Cost, Fair Value and Maturities of Short Term Investments (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Short-term investments - Cost	$ 14,228,126	$ 12,734,184
Short-term investments - Fair Value	14,257,998	12,724,020
Short-term investment maturities - Within 3 months, cost	5,383,488
Short-term investment maturities - Between 3-12 months, cost	8,844,638	12,734,184
Total, cost	14,228,126	12,734,184
Short-term investment maturities - Within 3 months, fair value	5,393,743
Short-term investment maturities - Between 3-12 months, fair value	8,864,255	12,724,020
Total, fair value	14,257,998	12,724,020
Corporate Debt Securities [Member]
Short-term investments - Cost	14,228,126	12,734,184
Short-term investments - Fair Value	$ 14,257,998	$ 12,724,020

Short Term Investments Available for Sale - Schedule of Unrealized Losses and Fair Value of Investment Securities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Less than 12 months, unrealized gains, fair value	$ 7,515,676	$ 748,148
Less than 12 months, unrealized losses, fair value	6,742,322	11,975,872
Investment securities - available for sale, at fair value	14,257,998	12,724,020
Less than 12 months, unrealized holding gains	38,068	570
Less than 12 months, unrealized holding losses	(8,196)	(10,734)
Unrealized holding gains (losses)	$ 29,872	$ (10,164)

Short Term Investments Available for Sale - Schedule of Investment Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Interest and dividends accrued and paid	$ 331,780	$ 26,041
Accretion of investment discounts and premiums, net	32,066
Losses investment maturity and sales, net	(10,164)
Investment income	$ 353,682	$ 26,041

Fair Values of Financial Instruments (Details Narrative) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3

Fair Values of Financial Instruments - Schedule of Fair Value of Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Investment securities, available for sale	$ 14,257,998	$ 12,724,020
Earn-out milestone liability	8,907,664	12,538,525
Corporate Debt Securities [Member]
Investment securities, available for sale	14,257,998	12,724,020
Fair Value, Measurements, Recurring [Member]
Earn-out milestone liability	8,907,664	12,538,525
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Earn-out milestone liability
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Earn-out milestone liability
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Earn-out milestone liability	8,907,664	12,538,525
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member]
Investment securities, available for sale	14,257,998	12,724,020
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Investment securities, available for sale
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Investment securities, available for sale	14,257,998	12,724,020
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Investment securities, available for sale
Fair Value, Measurements, Non-Recurring [Member] \| In Process R&D [Member]
Liabilities, fair value	15,736,491
Fair Value, Measurements, Non-Recurring [Member] \| In Process R&D [Member]
Liabilities, fair value		20,246,491
Fair Value, Measurements, Non-Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| In Process R&D [Member]
Liabilities, fair value
Fair Value, Measurements, Non-Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| In Process R&D [Member]
Liabilities, fair value
Fair Value, Measurements, Non-Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| In Process R&D [Member]
Liabilities, fair value
Fair Value, Measurements, Non-Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| In Process R&D [Member]
Liabilities, fair value
Fair Value, Measurements, Non-Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| In Process R&D [Member]
Liabilities, fair value	$ 15,736,491
Fair Value, Measurements, Non-Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| In Process R&D [Member]
Liabilities, fair value		$ 20,246,491

Acquisition of EGEN, Inc. (Details Narrative) - USD ($)		1 Months Ended		3 Months Ended				12 Months Ended
Acquisition of EGEN, Inc. (Details Narrative) - USD ($)	Jun. 20, 2014	Dec. 31, 2016	Jun. 20, 2014	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Asset impairment charges, total				$ 2,400,000		$ 2,500,000
Business Combination, Consideration Transferred, Liabilities Incurred				4,500,000
Finite-lived intangible assets, net, ending balance		$ 1,022,924			$ 795,608		$ 1,022,924	568,292	795,608	$ 1,022,924
Gain (Loss) from Change in Fair Value of Earn out Milestone Liability								(3,630,861)	(649,701)
Assets					47,514,433			46,855,587	47,514,433
Purchase Agreement [Member]
Finite-lived intangible assets, net, ending balance					795,608			568,292	795,608
Finite-lived intangible assets, accumulated amortization					795,606			1,022,922	795,606
IPR&D Drug Technology Platforms [Member]
Asset impairment charges, total		$ 1,400,000					$ 1,400,000
EGEN Inc [Member]
Potential future earn-out payments	$ 30,400,000		$ 30,400,000
Payments to Acquire Businesses, Gross			$ 3,000,000
Stock issued during period, shares, acquisitions			241,590
Business Combination, Consideration Transferred, Liabilities Incurred	13,900,000							8,900,000	12,500,000	$ 13,200,000
Gain (Loss) from Change in Fair Value of Earn out Milestone Liability						3,900,000		3,600,000	600,000
Goodwill, acquisition								2,000,000
EGEN Inc [Member] \| Purchase Agreement [Member]
Finite-lived intangible assets acquired								$ 1,600,000
Finite-lived intangible asset, useful life								7 years
Amortization expense								$ 227,316	227,316
EGEN Inc [Member] \| IPR&D Drug Technology Platforms [Member]
Indefinite lived intangible assets								24,200,000
EGEN Inc [Member] \| Glioblastoma Multiforme Brain Cancer [Member]
Asset impairment charges, total				$ 6,900,000	6,900,000	$ 9,400,000		4,510,000	2,520,000
IPR&D costs								15,736,491	20,246,491
EGEN Inc [Member] \| Ovarian Cancer [Member]
Finite-lived intangible assets, net, ending balance					$ 13,300,000			13,300,000	$ 13,300,000
Initial assets value								6,900,000
Assets								$ 2,400,000
EGEN Inc [Member] \| Maximum [Member]
Total purchase price for the asset acquisition			$ 44,400,000
Potential future earn-out payments	$ 30,400,000		$ 30,400,000

Acquisition of EGEN, Inc. - Schedule of Fair Values of Acquired Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Goodwill	$ 1,976,101	$ 1,976,101
EGEN Inc [Member]
Property and equipment, net	35,000
In-process research and development	24,211,000
Other Intangible assets (Covenant not to compete)	1,591,000
Goodwill	1,976,000
Total assets:	27,813,000
Accounts payable and accrued liabilities	(235,000)
Net assets acquired	$ 27,578,000

Acquisition of EGEN, Inc. - Amortization Schedule for Covenant Not to Complete (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total	$ 568,292	$ 795,608	$ 1,022,924
Noncompete Agreements [Member]
2019	227,316
2020	227,316
2021	113,660
Total	$ 568,292

Acquisition of EGEN, Inc. - Schedule of Fair Value of Assets Acquired (Details) - USD ($)	3 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Intangible assets, beginning balance			$ 795,608	$ 1,022,924
Amortization			(227,316)	(227,316)
Impairment charge	$ 2,400,000	$ 2,500,000
Intangible assets, ending balance			568,292	795,608
IPR&D [Member]
Intangible assets, beginning balance			20,246,491	22,766,491
Amortization
Impairment charge			(4,510,000)	(2,520,000)
Intangible assets, ending balance			15,736,491	20,246,491
Goodwill [Member]
Intangible assets, beginning balance			1,976,101	1,976,101
Amortization
Impairment charge
Intangible assets, ending balance			$ 1,976,101	$ 1,976,101

Property and Equipment - Summary of Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property and equipment, gross	$ 3,152,886	$ 3,014,487
Less accumulated depreciation and amortization	(2,968,259)	(2,838,716)
Total	$ 184,627	175,771
Minimum [Member]
Estimated useful life	3 years
Maximum [Member]
Estimated useful life	7 years
Machinery and Equipment [Member]
Property and equipment, gross	$ 2,596,170	$ 2,495,959
Machinery and Equipment [Member] \| Minimum [Member]
Estimated useful life	5 years	5 years
Machinery and Equipment [Member] \| Maximum [Member]
Estimated useful life	7 years	7 years
Furniture and Fixtures [Member]
Property and equipment, gross	$ 267,712	$ 248,709
Furniture and Fixtures [Member] \| Minimum [Member]
Estimated useful life	3 years	3 years
Furniture and Fixtures [Member] \| Maximum [Member]
Estimated useful life	5 years	5 years
Leasehold Improvements [Member]
Property and equipment, gross	$ 289,004	$ 269,819
Leasehold Improvements [Member] \| Minimum [Member]
Estimated useful life	5 years	5 years
Leasehold Improvements [Member] \| Maximum [Member]
Estimated useful life	7 years	7 years

Other Accrued Liabilities - Schedule of Other Accrued Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Amounts due to contract research organizations and other contractual agreements	$ 749,369	$ 665,373
Accrued payroll and related benefits	1,592,590	1,258,265
Accrued professional fees	198,654	264,668
Other	45,285	94,521
Total	$ 2,585,898	$ 2,282,827

Note Payable (Details Narrative) - USD ($)					1 Months Ended		6 Months Ended	12 Months Ended			19 Months Ended	26 Months Ended
Note Payable (Details Narrative) - USD ($)	Jun. 27, 2018	Jun. 10, 2014	Jun. 10, 2014	Nov. 25, 2013	Jun. 20, 2014	Nov. 30, 2013	Jun. 10, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 15, 2016	Dec. 31, 2018	Dec. 17, 2015	Jun. 26, 2017
Class of warrant or right, exercise price of warrants or rights								$ 5.75			$ 5.75		$ 1.65
Financing fees and expenses								$ 712,025	$ 91,756
Hercules Warrant [Member]
Debt instrument, unamortized discount, total		$ 476,261	$ 476,261				$ 476,261
Horizon Credit Agreement [Member]
Percentage of outstanding principle balance, description
Interest expense, debt, total								$ 512,872
Amortization of debt issuance costs								199,153
Horizon Credit Agreement [Member] \| Horizon Warrants [Member]
Class of warrant or right, number of securities called by each warrant or right	190,114
Class of warrant or right, exercise price of warrants or rights	$ 2.63
Debt instrument, unamortized discount, total	$ 507,116
Horizon Credit Agreement [Member] \| LIBOR plus [Member]
Line of credit, interest rate	7.625%
Debt effective interest rate	9.98%
Hercules Credit Agreement [Member]
Interest expense, debt, total								56,386
Amortization of debt issuance costs								$ 35,370
Hercules Credit Agreement [Member] \| Hercules Warrant [Member]
Class of warrant or right, number of securities called by each warrant or right				6,963
Class of warrant or right, exercise price of warrants or rights				$ 50.26
Debt issuance costs, gross		350,000	$ 350,000				350,000
Warrant date				Nov. 25, 2018
Hercules Credit Agreement [Member] \| Prime Rate [Member]
Debt instrument, basis spread on variable rate										11.50%	11.75%	11.25%
Hercules Credit Agreement [Member] \| Hercules [Member]
Proceeds from lines of credit, total							$ 10,000,000
Debt instrument, unamortized discount, total						$ 230,000
Debt issuance costs, net, total						122,378
EGEN Inc [Member]
Payments to acquire businesses, gross					$ 3,000,000
EGEN Inc [Member] \| Hercules Credit Agreement [Member]
Payments to acquire businesses, gross		$ 3,000,000
Second Tranche [Member] \| Hercules Credit Agreement [Member]
Class of warrant or right, number of securities called by each warrant or right		6,963	6,963				6,963
Percentage for original debt, amount			3.50%
Original debt, amount			$ 5,000,000
Loan Agreement [Member] \| Horizon Technology Finance Corporation [Member]
Line of credit facility, maximum borrowing capacity	$ 10,000,000
Loan Agreement [Member] \| Hercules Technology Growth Capital, Inc. [Member]
Line of credit facility, maximum borrowing capacity						20,000,000
Horizon Credit Agreement [Member]
Proceeds from lines of credit, total	$ 10,000,000
Percentage of outstanding principle balance, description	an amount equal to 1-3%
Debt instrument, unamortized discount, total	$ 782,116
Financing fees and expenses	175,000
Loan origination fees	$ 100,000
Percentage for original debt, amount	4.00%
Debt issuance costs, gross	$ 400,000
Hercules Credit Agreement [Member] \| First Tranche [Member]
Proceeds from lines of credit, total						5,000,000
Repayments of lines of credit						$ 4,000,000
Hercules Credit Agreement [Member] \| Second Tranche [Member]
Proceeds from lines of credit, total		$ 5,000,000

Note Payable - Schedule of Future Principle Payments, Net of Unamortized Debt Discounts (Details)	Dec. 31, 2018 USD ($)
Debt Disclosure [Abstract]
2019
2020
2021	4,583,333
2022	5,000,000
2023 and thereafter	416,667
Subtotal of future principle payments	10,000,000
Net of unamortized debt issuance costs	(582,963)
Total	$ 9,417,037

Income Taxes (Details Narrative) - USD ($)	1 Months Ended	5 Months Ended			11 Months Ended	12 Months Ended		20 Months Ended	25 Months Ended
Income Taxes (Details Narrative) - USD ($)	Jul. 31, 2011	Oct. 31, 2017	Jun. 30, 2017	Jun. 30, 2013	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Feb. 28, 2013	Feb. 28, 2017	Jun. 30, 2015
Income tax, description						The Tax Reform Act permanently reduces the U.S. corporate income tax rate from a maximum of 35% to a flat 21% rate, effective January 1, 2018.
Income tax, U.S. corporate income tax rate						21.00%	21.00%
Net operating losses	$ 4,200,000	$ 800,000	$ 300,000	$ 1,500,000	$ 1,500,000	$ 229,700,000		$ 1,400,000	$ 300,000	$ 1,600,000
Net operating losses, unused						$ 222,200,000
Net operating losses expiration, description						Expire starting in 2023 through 2037
Net operating losses carryforward limits, description						The deduction for net operating losses incurred in tax years beginning after January 1, 2018 is limited to 80% of annual taxable income
Operating loss carry forwards, limitation on use	$ 90,000,000	$ 5,000,000	$ 7,000,000	$ 4,000,000	$ 30,000,000			$ 34,000,000	$ 35,000,000	$ 40,000,000
Operating loss carry forwards, limitation on use						The Company determined that it experienced ownership changes, as defined by Section 382, in connection with certain common stock offerings in July 2011, February 2013, June 2013, June 2015, February 2017, June 2017, October 2017 and August 2018. As a result, the utilization of the Company's federal tax net operating loss carry forwards generated prior to the ownership changes are limited. As of December 31, 2018, the Company has net operating loss carry forwards for U.S. federal and state tax purposes of approximately $233 million, before excluding net operating losses that have been limited as a result of Section 382 limitations. The annual limitation due to Section 382 for net operating loss carry forward utilization is approximately $4.2 million per year for approximately $90 million in net operating loss carry forwards existing at the ownership change occurring in July 2011, approximately $1.4 million per year for approximately $34 million of additional net operating losses occurring from July 2011 to the ownership change that occurred in February 2013, approximately $1.5 million per year for approximately $4 million of additional net operating losses occurring from February 2013 to the ownership change that occurred in June 2013, approximately $1.6 million per year for approximately $40 million of additional net operating losses occurring from June 2013 to the ownership change that occurred in June 2015, approximately $0.3 million per year for approximately $35 million of additional net operating losses occurring from June 2015 to the ownership change that occurred in February 2017, approximately $0.3 million per year for approximately $7 million of additional net operating losses occurring from February 2017 to the ownership change that occurred in June 2017, approximately $0.8 million per year for approximately $5 million of additional net operating losses occurring from June 2017 to the ownership change that occurred in October 2017, and approximately $1.5 million per year for approximately $30 million of additional net operating losses occurring from October 2017 to the ownership change that occurred in August 2018. The utilization of these net operating loss carry forwards may be further limited if the Company experiences future ownership changes as defined in Section 382 of the Internal Revenue Code.
New Jersey [Member]
Proceeds from sale of NOLs						$ 10,400,000
Federal Income Tax [Member]
Net operating losses						7,500,000
U.S. Federal and State Tax [Member]
Net operating losses						$ 23,300,000
Tax Reform Act [Member]
Income tax, U.S. corporate income tax rate						21.00%

Income Taxes - Schedule of Income Tax Provision (Benefit) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal, Current
Federal, Deferred
State and Local, Current	(10,419,000)
State and Local, Deferred
Effective tax rate	$ (10,419,115)

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%
State taxes, net of federal tax benefit	36.90%	6.60%
Permanent differences	3.80%	0.00%
Other	(9.40%)	0.00%
Change in valuation allowance and deferred rate change, net	2.00%	(27.60%)
Effective tax rate	46.70%	0.00%

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 51,498,000	$ 62,216,000
Other Deferred tax assets, net	1,092,000	2,415,000
Subtotal	52,590,000	64,631,000
Valuation allowance	(52,590,000)	(64,631,000)
Total deferred tax asset

Stockholders' Equity (Details Narrative) - USD ($)															1 Months Ended	3 Months Ended	12 Months Ended		68 Months Ended
Stockholders' Equity (Details Narrative) - USD ($)	Dec. 04, 2018	Oct. 27, 2018	Oct. 26, 2018	Aug. 31, 2018	Oct. 27, 2017	Oct. 27, 2017	Oct. 04, 2017	Jul. 06, 2017	Jun. 09, 2017	May 26, 2017	May 16, 2017	Feb. 14, 2017	May 27, 2015	Feb. 01, 2013	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018	Jun. 26, 2017	Jun. 30, 2016	Jan. 15, 2014	Feb. 22, 2013
Shelf registration statement amount															$ 75,000,000
Common stock, shares authorized																112,500,000	112,500,000	112,500,000			75,000,000
Preferred stock, shares authorized																100,000	100,000	100,000
Aggregate of common and preferred stock, shares authorized																	112,600,000
Reverse stock split										14-for-1 reverse stock split
Stock issued during period split stock										14	56,982,418
Stock issued during period reverse stock split										14	4,070,172
Class of warrant or right, outstanding											2,400,000						1,600,000
Share-based compensation arrangement by share-based payment award, options, outstanding, number, ending balance											200,000						3,148,743
Common stock, par or stated value per share																$ 0.01	$ 0.01	$ 0.01
Class of warrant or right, number of securities called by warrants or rights																9,231,628	190,114	9,231,628		506,627
Class of warrant or right, exercise price of warrants or rights																	$ 5.75			$ 1.65
Proceeds from warrant exercises																		$ 21,140,304
Fair value of common stock issued as equity issuance costs and charged against paid in capital																	450,000
Series AA Warrant [Member]
Stock issued during period, shares, exercise of warrants																		747,254
Proceeds from warrant exercises																		$ 2,400,000
Pre-Funded Series BB Warrant [Member]
Stock issued during period, shares, exercise of warrants																		185,713
2013 Warrants, 2014 Warrants, and June 2016 Warrants [Member]
Proceeds from warrant exercises									$ 2,100,000
Increase (decrease) in fair value of warrants									$ 200,000
2015 Warrants [Member]
Proceeds from warrant exercises													$ 800,000
Increase (decrease) in fair value of warrants													100,000
June 2016 Warrants [Member]
Proceeds from warrant exercises													$ 800,000
July 2017 Direct Offering [Member]
Stock issued during period, shares, new issues								2,050,000
Class of warrant or right, number of securities called by each warrant or right							4,665,000
Share price								$ 2.07
Proceeds from issuance of common stock, gross								$ 4,243,500
Proceeds from issuance of warrants							$ 16,600,000
July 2017 Direct Offering [Member] \| Pre-Funded Series CCC Warrants [Member]
Class of warrant or right, number of securities called by warrants or rights								385,000
Class of warrant or right, offered price of warrants or rights								$ 2.06
Beneficial ownership percentage threshold								9.99%
Proceeds from issuance of warrants								$ 793,100
Class of warrant or right, exercise price of warrants or rights								$ 0.01
Class of warrant or right, exercised during period																385,000
July 2017 Direct Offering [Member] \| Series AAA Warrants [Member]
Class of warrant or right, number of securities called by warrants or rights								2,435,000
Class of warrant or right, exercise price of warrants or rights							$ 2.07	$ 2.07
July 2017 Direct Offering [Member] \| Series BBB Warrants [Member]
Class of warrant or right, number of securities called by warrants or rights								2,435,000
Class of warrant or right, exercise price of warrants or rights							$ 4.75	$ 4.75
July 2017 Direct Offering [Member] \| Series DDD Warrants [Member]
Class of warrant or right, number of securities called by warrants or rights							1,166,250
Class of warrant or right, number of securities called by each warrant or right							1
Warrants issued, expiration period							1 year
Class of warrant or right, exercise price of warrants or rights							$ 6.20
February 14, 2017 Public Offering [Member]
Stock issued during period, shares, new issues												1,384,704
Shares issued, price per share												$ 3.22
Maximum beneficial ownership of the purchaser												9.99%
Proceeds from issuance of common stock												$ 5,000,000
February 14, 2017 Public Offering [Member] \| Series AA Warrant [Member]
Class of warrant or right, number of securities called by warrants or rights												1,177,790
Number of warrant to surrender			321,428
Number of exchange surrender received common stock			160,414
Broker and legal fees			$ 100,000
Class of warrant or right, exercise price of warrants or rights												$ 3.22
Class of warrant or right, term												5 years
February 14, 2017 Public Offering [Member] \| Pre-Funded Series BB Warrant [Member]
Class of warrant or right, number of securities called by warrants or rights												185,713
Class of warrant or right, exercise price of warrants or rights												$ 0.14
Shares issued, price per share												$ 3.08
May 2015 Common Stock Offering [Member] \| 2015 Warrants [Member]
Class of warrant or right, number of securities called by warrants or rights													139,284
Class of warrant or right, exercise price of warrants or rights													$ 36.40
Aspire Purchase Agreement [Member]
Fair value of common stock issued as equity issuance costs and charged against paid in capital															$ 450,000
ATM Agreement [Member]
Stock issued during period, shares, new issues																			1,784,396
Proceeds from issuance of common stock																			$ 12,800,000
Aggregate offering price														$ 25,000,000
Proceeds from sale equity																	$ 1,200,000	$ 3,900,000
Sale of common stock, shares																	457,070	1,221,348
Investor [Member]
Class of warrant or right, outstanding																7,617,148		7,617,148
Class of warrant or right, number of securities called by warrants or rights																	1,600,000
Proceeds from issuance of warrants																		$ 22,000,000
Underwriting Agreement [Member] \| Oppenheimer & Co. Inc. [Member]
Stock issued during period, shares, new issues					2,640,000
Common stock, par or stated value per share					$ 0.01	$ 0.01
Class of warrant or right, number of securities called by warrants or rights					1,320,000	1,320,000
Warrant, description					Each share of Common Stock is being sold together with 0.5 warrants (the "Investor Warrants"), each whole Investor Warrant being exercisable for one share of Common Stock, at an offering price of $2.50 per share and related Investor Warrants.
Warrant Exchange Agreements [Member]
Stock issued during period, shares, new issues																	820,714
Warrant Exchange Agreements [Member] \| February 14, 2017 Public Offering [Member]
Number of exchange surrender received common stock			321,428
Broker and legal fees			$ 130,000
Warrant Exchange Agreements [Member] \| Investor [Member]
Number of warrant to surrender			1,320,000
Number of exchange surrender received common stock			820,714
Exercise Agreements [Member] \| 2013 Warrants, 2014 Warrants, and June 2016 Warrants [Member]
Class of warrant or right, number of securities called by warrants or rights																							790,410
Class of warrant or right, exercise price of warrants or rights																							$ 2.70
Aspire Purchase Agreement [Member]
Stock issued during period, shares, new issues				164,835
Aggregate offering price, additions				$ 15,000,000
Aggregate offering price, term				24 months
Aggregate offering price				$ 15,000,000
Maximum number of shares purchased per day				100,000
Aggregate offering price, description				The lowest sale price of the Company's common stock on the purchase date; or the arithmetic average of the three (3) lowest closing sale prices for the Company's common stock during the ten (10) consecutive trading days ending on the trading day immediately preceding the purchase date.
Maximum number of shares purchased per day, additional				2,000,000
Aspire purchase agreement, terms				In addition, on any date on which the Company submits a Purchase Notice to Aspire Capital in an amount equal to at least 100,000 shares, the Company also has the right, in its sole discretion, to present Aspire Capital with a volume-weighted average price purchase notice (each, a "VWAP Purchase Notice") directing Aspire Capital to purchase an amount of stock equal to up to 30% of the aggregate shares of the Company's common stock traded on its principal market on the next trading day (the "VWAP Purchase Date"), subject to a maximum number of shares the Company may determine. The purchase price per share pursuant to such VWAP Purchase Notice is generally 97% of the volume-weighted average price for the Company's common stock traded on its principal market on the VWAP Purchase Date.
Purchase Agreement [Member]
Stock issued during period, shares, new issues																	100,000
Proceeds from issuance of common stock																	$ 200,000
Purchase Agreement [Member] \| March 28, 2019 [Member]
Stock issued during period, shares, new issues																	600,000
Proceeds from issuance of common stock																	$ 1,300,000
Capital on DemandTM Sales Agreement [Member]
Aggregate offering price	$ 16,000,000
Aggregate offering price, description	(i) the sale of all shares of our common stock subject to the Sales Agreement, and (ii) the termination of the Capital on Demand Agreement by JonesTrading or Celsion. The Capital on Demand Agreement may be terminated by JonesTrading or the Company at any time upon 10 days' notice to the other party, or by JonesTrading at any time in certain circumstances, including the occurrence of a material adverse change in the Company.
Commission percentage for gross proceeds from common stock	3.00%
Capital on Demand Agreement [Member] \| March 28, 2019 [Member]
Stock issued during period, shares, new issues																	122,186
Proceeds from issuance of common stock																	$ 300,000
Warrant [Member]
Class of warrant or right, outstanding											33,500,000						1,200,000
Share-based compensation arrangement by share-based payment award, options, outstanding, number, ending balance											2,400,000
Class of warrant or right, number of securities called by each warrant or right					2.325	2.325
Class of warrant or right, offered price of warrants or rights					$ 3.00	$ 3.00
Warrants issued, expiration period		5 years
Warrant [Member] \| Maximum [Member]
Class of warrant or right, number of securities called by warrants or rights									790,410													64,348	95,811
Class of warrant or right, exercise price of warrants or rights									$ 2.70													$ 57.40	$ 74.34
Investor Warrants [Member] \| October 2017 Underwritten Offering [Member]
Class of warrant or right, number of securities called by warrants or rights					66,000	66,000
Class of warrant or right, number of securities called by each warrant or right					2.87	2.87
Warrants issued, expiration period						5 years
Proceeds from issuance of common stock and warrants						$ 6,600,000
Investor Warrants [Member] \| Underwriting Agreement [Member] \| Oppenheimer & Co. Inc. [Member]
Class of warrant or right, number of securities called by each warrant or right					2.50	2.50

Stock-Based Compensation (Details Narrative) - USD ($)		1 Months Ended	12 Months Ended
Stock-Based Compensation (Details Narrative) - USD ($)	Sep. 28, 2018	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	May 16, 2017
Number of shares reserved for future issuance		3,148,743	3,148,743		200,000
2018 Stock Incentive Plan [Member]
Equity awards, number of stock authorized		2,700,000	2,700,000
Percentage of fair market value of shares		100.00%	100.00%
Percentage of outstanding stock determining factor for incentive stock price		10.00%	10.00%
Compensation cost			$ 4,600,000	$ 1,100,000
Stock based compensation cost expected to be recognized, weighted average period			10 months 25 days
Weighted average grant date fair value of stock option awards granted			$ 2.36	$ 2.32
2018 Stock Incentive Plan [Member] \| Minimum [Member]
Percentage of fair market value of shares		110.00%	110.00%
2007 Stock Incentive Plan [Member]
Equity awards, number of stock authorized		688,531	688,531
Unrecognized compensation cost related to non-vested stock based compensation		$ 1,800,000	$ 1,800,000
Inducement Option Grants [Member] \| Three New Employees [Member]
Inducement option grant, exercise price per share	$ 2.77
Options expiration period	10 years
Number of equity awards granted		106,502
Inducement Option Grants [Member] \| Three New Employees [Member] \| Restricted Stock Awards [Member]
Shares issued	164,004
Restricted Stock Awards [Member]
Weighted average grant date fair value of stock option awards granted			$ 2.71	$ 42.20
Restricted Stock Awards [Member] \| Inducement Option Grants [Member] \| Three New Employees [Member]
Shares issued	19,000
Equity Stock Awards [Member]
Number of shares reserved for future issuance		3,399,893	3,399,893
Number of equity awards granted			3,064,741
Number of equity awards available for future issuance		335,152	335,152

Stock-Based Compensation - Schedule of Stock Option Awards and Restricted Stock Grants (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Number Outstanding, Ending Balance	3,148,743
Number Outstanding, Exercisable	1,689,902
Stock Options [Member]
Number Outstanding, Outstanding, Beginning Balance	703,442	211,213
Number Outstanding, Granted	2,629,004	535,964
Number Outstanding, Cancelled or expired	(183,703)	(43,735)
Number Outstanding, Ending Balance	3,148,743	703,442
Number Outstanding, Exercisable	1,689,902
Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 10.34	$ 61.59
Weighted Average Exercise Price, Granted	2.26	2.69
Weighted Average Exercise Price, Cancelled or expired	25.96	164.12
Weighted Average Exercise Price, Outstanding, Ending Balance	2.67	$ 10.34
Weighted Average Exercise Price, Excercisable	$ 2.97
Weighted Average Remaining Contractual Term (years), Outstanding, Ending Balance	9 years 2 months 12 days
Weighted Average Remaining Contractual Term (years), Exercisable	9 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding, Ending Balance
Aggregate Intrinsic Value, Exercisable

Stock-Based Compensation - Summary of Non-vested Restricted Stock Awards (Details) - Restricted Stock Awards [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Number Outstanding, Non-vested stock awards outstanding, Beginning Balance		4,785
Number Outstanding, Non-vested stock awards outstanding, Granted	35,000	(3,357)
Number Outstanding, Non-vested stock awards outstanding, Vested and issued	(6,000)	(1,428)
Number Outstanding, Non-vested stock awards outstanding, Forfeited	(6,500)
Number Outstanding, Non-vested stock awards outstanding, Ending Balance	22,500
Weighted Average Grant Date Fair Value, Beginning Balance		$ 37.42
Weighted Average Grant Date Fair Value, Granted	2.71	42.20
Weighted Average Grant Date Fair Value, Vested and issued	2.77	26.18
Weighted Average Grant Date Fair Value, Forfeited	2.64
Weighted Average Grant Date Fair Value, Ending Balance	$ 2.72

Stock-Based Compensation - Summary of Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	May 16, 2017
Options Outstanding, Number	3,148,743	200,000
Options Exercisable, Number	1,689,902
Exercise Price One [Member]
Range of Exercise Prices, Upper	$ 5.00
Options Outstanding, Number	3,084,252
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	9 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 2.34
Options Exercisable, Number	1,625,807
Options Exercisable, Weighted Average Remaining Contractual Term (in years)	9 years 2 months 12 days
Options Exercisable, Weighted Average Exercise Price	$ 2.34
Exercise Price Two [Member]
Range of Exercise Prices, Upper	81.90
Range of Exercise Prices, Lower	$ 5.00
Options Outstanding, Number	64,491
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	7 years
Options Outstanding, Weighted Average Exercise Price	$ 19.00
Options Exercisable, Number	64,095
Options Exercisable, Weighted Average Remaining Contractual Term (in years)	7 years
Options Exercisable, Weighted Average Exercise Price	$ 19.00

Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Options Granted (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Expected life (in years)		10 years
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Risk-free interest rate	2.82%	2.21%
Expected volatility	99.90%	90.40%
Expected life (in years)	8 years 6 months
Maximum [Member]
Risk-free interest rate	3.02%	1.32%
Expected volatility	102.10%	100.80%
Expected life (in years)	10 years

Earn-out Milestone Liability (Details Narrative) - USD ($)		3 Months Ended		12 Months Ended
	Jun. 20, 2014	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair value of Acquisition consideration		$ 4,500,000
Gain (loss) from change in fair value of earn out milestone liability				$ (3,630,861)	$ (649,701)
EGEN Inc [Member]
Future earn-out payments	$ 30,400,000
Fair value of Acquisition consideration	$ 13,900,000			$ 8,900,000	12,500,000	$ 13,200,000
Risk adjusted assessment of each milestone				80.00%
Estimated time to achieve the milestone				1 year 2 months 30 days
Gain (loss) from change in fair value of earn out milestone liability			$ 3,900,000	$ 3,600,000	$ 600,000
EGEN Inc [Member] \| Minimum [Member]
Risk adjusted assessment of each milestone	10.00%				50.00%
Estimated time to achieve the milestone	1 year 6 months				1 year 3 months 19 days
EGEN Inc [Member] \| Maximum [Member]
Future earn-out payments	$ 30,400,000
Risk adjusted assessment of each milestone	67.00%				80.00%
Estimated time to achieve the milestone	2 years 6 months				1 year 6 months
EGEN Inc [Member]
Gain (loss) from change in fair value of earn out milestone liability			$ 1,400,000

Earn-out Milestone Liability - Schedule of Changes in Earn-out Milestone Liability (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Earn-out Milestone Liability
Earn-out liabilities, beginning balance	$ 12,538,525	$ 13,188,226
Non-cash charge from the adjustment for the change in fair value included in net loss	(3,630,861)	(649,701)
Earn-out liabilities, ending balance	$ 8,907,664	$ 12,538,525

Warrants (Details Narrative) - USD ($)	12 Months Ended
Warrants (Details Narrative) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Jun. 26, 2017	May 16, 2017
Number of shares, Warrant rights	190,114	9,231,628	506,627
Warrants outstanding	1,600,000			2,400,000
Warrants, weighted average exercise price	$ 5.75		$ 1.65
Warrants expiring	44,037	13,927
Warrant [Member]
Warrants outstanding	1,200,000			33,500,000
Strike price per share	$ 6.20
Warrant expiration date	Apr. 04, 2019
Warrant Exchange Agreements [Member]
Common stock shares issued	820,714
Investor [Member]
Number of shares, Warrant rights	1,600,000
Warrants outstanding		7,617,148
Proceeds from warrant		$ 22,000,000

Warrants - Summary of Warrant Activity (Details) - Warrant [Member] - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Number of Warrants Issued, Warrants outstanding, Beginning Balance	3,058,402	1,487,958
Number of Warrants Issued, Warrants issued	190,114	9,231,628
Number of Warrants Issued, Warrants exercised		(7,617,147)
Number of Warrants Issued, Warrants cancelled in exchange for common stock	(1,641,427)
Number of Warrants Issued, Warrants expired	(13,927)	(44,037)
Number of Warrants Issued, Warrants outstanding and exercisable, Ending Balance	1,593,162	3,058,402
Weighted Average Exercise Price, Warrants outstanding, Beginning Balance	$ 5.29	$ 9.39
Weighted Average Exercise Price, Warrants issued	2.63	3.46
Weighted Average Exercise Price, Warrants exercised		2.89
Weighted Average Exercise Price, Warrants cancelled in exchange for common stock	3.04
Weighted Average Exercise Price, Warrants expired	226.24	209.23
Weighted Average Exercise Price, Warrants outstanding and exercisable, Ending Balance	$ 5.36	$ 5.29
Aggregate intrinsic value of outstanding warrants
Weighted average remaining contractual terms (years)	1 year 10 months 14 days

Licenses of Intellectual Property and Patents (Details Textual)	12 Months Ended
	Dec. 31, 2018 USD ($) Trademark shares	Dec. 31, 2017 USD ($) shares	Jan. 31, 2003 USD ($) shares
Common stock, shares, issued \| shares	18,832,168	17,277,299
Common stock, value, issued \| $	$ 188,322	$ 172,772
Number of trademark protection application pending for thermo dox \| Trademark	14
License Agreement [Member] \| Duke University [Member]
Number of days before issuance factoring into average closing price	20 days
Amount of time after effective date of license agreement for registration rights to take place	1 year
Common stock, shares, issued \| shares			253,691
Common stock, value, issued \| $			$ 2,200,000

Technology Development and Licensing Agreements (Details Narrative) - USD ($)		3 Months Ended
	Jan. 18, 2013	Mar. 31, 2013	Dec. 31, 2018	Sep. 30, 2013
Deferred revenue				$ 5,000,000
Deferred revenue amortization period		10 years
Contract liabilities			$ 5,000,000
Hisun [Member]
Non-refundable research and development fee	$ 5,000,000

Commitments (Details Narrative)	1 Months Ended				6 Months Ended	12 Months Ended
Commitments (Details Narrative)	Jan. 31, 2018 USD ($) ft²	Apr. 30, 2017 USD ($) ft²	Apr. 30, 2012 USD ($)	Jul. 31, 2011 ft²	Jun. 30, 2014 USD ($) ft²	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2014 ft²
Irrevocable and unconditional standby letter of credit						$ 749,369	$ 665,373
Payment of lease						$ 457,321	$ 502,716
EGEN Asset Purchase Agreement [Member]
Area of premises \| ft²					11,500
Lease term					1 year
Operating lease, description						On February 1, 2019, we amended the current terms of the lease to increase the size of the premises by 2,285 square feet to 9,850 square feet and also extended the lease term by one year to September 1, 2023. In conjunction with the February 1, 2019 lease amendment, we agreed to modify our one-time option to cancel the lease as of the 36th month after the May 1, 2017 lease commencement date
Operating leases, monthly rent payment in final year					$ 23,200
Standby Letter of Credit [Member]
Contractual obligation reduction nineteen months from initial term			$ 50,000
Contractual obligation remaining			100,000
Lawrenceville New Jersey [Member]
Area of premises \| ft²		7,565		10,870
Lease term		64 months		66 months
The number of months in which free rent is provided		4 months		6 months
Payment for rent			23,000
Operating leases, monthly rent payment in first year		$ 18,900
Operating leases, monthly rent payment in final year		$ 20,500
Lawrenceville New Jersey [Member] \| Standby Letter of Credit [Member]
Irrevocable and unconditional standby letter of credit			$ 250,000
Huntsville Alabama [Member] \| EGEN Asset Purchase Agreement [Member]
Area of premises \| ft²	9,049							2,285
Lease term	60 months
Operating leases, monthly rent payment	$ 18,100

Commitments - Summary of the Future Minimum Payments Required Under Leases (Details)	Dec. 31, 2017 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2019	$ 450,430
2020	454,213
2021	457,995
2022	379,823
2023	18,098
Total minimum lease payments	$ 1,760,559

Subsequent Events (Details Narrative) - USD ($)	Mar. 28, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 26, 2017
Warrants to purchase common stock		190,114	9,231,628	506,627
Warrants strike price		$ 5.75		$ 1.65
Subsequent Event [Member] \| Asset Purchase Agreement [Member] \| EGWU, Inc [Member]
Warrants to purchase common stock	200,000
Warrants strike price	$ 0.01
Subsequent Event [Member] \| Asset Purchase Agreement [Member] \| Ovarian Cancer [Member]
Future earn-out payments	$ 12,400,000
Cash consideration payable	7,000,000
Consideration payble by issuane of stock	$ 12,400,000