Fibrocell Science (FCSC) 10-K 27 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Mar. 20, 2019	Jun. 29, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	Fibrocell Science, Inc.
Entity Central Index Key	0000357097
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Trading Symbol	FCSC
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		9,758,332
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 16.8

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 14,430	$ 17,417
Prepaid expenses and other current assets	105	485
Total current assets	14,535	17,902
Property and equipment, net of accumulated depreciation of $2,311 and $1,919, respectively	1,222	1,470
Other assets	1	39
Total assets	15,758	19,411
Current liabilities:
Accounts payable	452	862
Related party payable	100	2,303
Accrued expenses	1,470	1,260
Deferred rent, current	150	0
Total current liabilities	2,172	4,425
Convertible promissory notes, net of debt discount of $18,003 and $18,003, respectively (see Note 6)	0	0
Accrued interest payable	1,738	967
Warrant liability	152	1,073
Derivative liability	1,474	3,136
Deferred rent	665	803
Total liabilities	6,201	10,404
Commitments and contingencies (Note 14)
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; 8,000 shares issued and outstanding as of December 31, 2018; 5,000,000 shares authorized, 8,000 shares issued and outstanding as of December 31, 2017; aggregate liquidation preference of $8,600 at December 31, 2018 and $8,264 at December 31, 2017	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized, 9,758,332 shares issued and outstanding as of December 31, 2018; 150,000,000 shares authorized, 5,189,755 shares issued and outstanding as of December 31, 2017	10	5
Additional paid-in capital	198,627	187,805
Accumulated deficit	(189,080)	(178,803)
Total stockholders’ equity	9,557	9,007
Total liabilities and stockholders’ equity	$ 15,758	$ 19,411

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 2,311	$ 1,919
Debt discount	$ 18,003	$ 18,003
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred shares outstanding (in shares)	8,000	8,000
Preferred shares issued (in shares)	8,000	8,000
Preferred stock, liquidation preference	$ 8,600	$ 8,264
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	9,758,332	5,189,755
Common stock, shares outstanding (in shares)	9,758,332	5,189,755

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Total revenues	$ 0	$ 0
Research and development expenses	6,018	6,512
Selling, general and administrative expenses	6,405	6,749
Total operating expenses	12,389	18,981
Total operating expenses	(12,389)	(18,981)
Other income (expense):
Warrant revaluation income	921	4,920
Derivative revaluation income (expense)	1,662	(1,407)
Interest expense	(771)	(828)
Other income, net	300	56
Loss before income taxes	(10,277)	(16,240)
Income taxes	0	0
Net loss	(10,277)	(16,240)
Dividend paid in-kind to preferred stockholders	(336)	(264)
Deemed dividend on preferred stock (see Note 8)	(513)	(4,099)
Net loss attributable to common stockholders	$ (11,126)	$ (20,603)
Net loss
Basic (in dollars per share)	$ (1.45)	$ (6.66)
Diluted (in dollars per share)	$ (1.45)	$ (6.67)
Weighted average number of common shares outstanding
Basic (in shares)	7,693,191	3,092,543
Diluted (in shares)	7,693,191	3,093,727
Affiliated Entity
Research and development expenses	$ (34)	$ 5,720

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock	Preferred Stock	Preferred StockSeries A Convertible Preferred Stock	Common Stock	Additional paid-in capital	Additional paid-in capitalSeries A Convertible Preferred Stock	Accumulated deficit	May 2018 Registered Direct Offering	May 2018 Registered Direct OfferingCommon Stock	May 2018 Registered Direct OfferingAdditional paid-in capital	July 2018 Registered Direct Offering	July 2018 Registered Direct OfferingCommon Stock	July 2018 Registered Direct OfferingAdditional paid-in capital	December 2018 Private Placement	December 2018 Private PlacementCommon Stock	December 2018 Private PlacementAdditional paid-in capital
Balance, preferred stock (shares) at Dec. 31, 2016			0
Balance at Dec. 31, 2016	$ 7,861		$ 0		$ 15	$ 170,409		$ (162,563)
Balance, common stock (shares) at Dec. 31, 2016					2,939,329
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of the March 2017 and May 2018 reverse stock splits on common stock and additional paid in capital, beginning balance					$ (12)	12
Issuance of stock (shares)				8,000	2,244,053
Issuance of stock	9,305	$ 7,623			$ 2	9,303	$ 7,623
Stock-based compensation expense	322					322
Exercise of liability-classified warrants (shares)					1,389
Exercise of liability-classified warrants	41					41
Conversion of promissory notes (shares)					4,984
Conversion of promissory notes	95					95
Net loss	$ (16,240)							(16,240)
Balance, preferred stock (shares) at Dec. 31, 2017	8,000		8,000
Balance at Dec. 31, 2017	$ 9,007		$ 0		$ 5	187,805		(178,803)
Balance, common stock (shares) at Dec. 31, 2017	5,189,755				5,189,755
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (shares)										2,038,224			1,474,080			443,350
Issuance of stock									$ 5,324	$ 2	$ 5,322	$ 3,591	$ 1	$ 3,590	$ 863	$ 1	$ 862
Stock-based compensation expense	$ 526					526
Exercise of liability-classified warrants (shares)					129,702
Exercise of liability-classified warrants	499					499
Net loss	(10,277)							(10,277)
Conversion of pre-funded units (shares)					483,221
Conversion of pre-funded units	$ 24				$ 1	23
Balance, preferred stock (shares) at Dec. 31, 2018	8,000		8,000
Balance at Dec. 31, 2018	$ 9,557		$ 0		$ 10	$ 198,627		$ (189,080)
Balance, common stock (shares) at Dec. 31, 2018	9,758,332				9,758,332

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Issuance costs		$ 1,175
Series A Convertible Preferred Stock | Preferred Stock
Issuance costs		$ 377
May 2018 Registered Direct Offering
Issuance costs	$ 676
July 2018 Registered Direct Offering
Issuance costs	494
December 2018 Private Placement
Issuance costs	$ 37

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (10,277)	$ (16,240)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	526	322
Warrant liability revaluation income	(921)	(4,920)
Derivative liability revaluation expense (income)	(1,662)	1,407
Loss on disposal or impairment of property and equipment	0	40
Depreciation and amortization	392	384
Amortization of discount on convertible debt converted to common shares	0	86
Decrease (increase) in operating assets:
Prepaid expenses and other current assets	380	28
Other assets	38	26
Increase (decrease) in operating liabilities:
Accounts payable	(24)	69
Related party payable	(2,203)	1,361
Accrued expenses and deferred rent	263	(342)
Accrued interest payable	771	742
Net cash used in operating activities	(12,717)	(17,037)
Cash flows from investing activities:
Purchase of property and equipment	(164)	(433)
Net cash used in investing activities	(164)	(433)
Cash flows from financing activities:
Proceeds from private placement	900	7,623
Proceeds from common stock offerings, (net of offering costs of $1,170)	8,915	9,749
Proceeds from exercise of common warrants	499	0
Proceeds from exercise of pre-funded warrants	24	0
Payment of deferred offering costs	(444)	0
Net cash provided by financing activities	9,894	17,372
Net decrease in cash and cash equivalents	(2,987)	(98)
Cash and cash equivalents, beginning of period	17,417	17,515
Cash and cash equivalents, end of period	14,430	17,417
Noncash Investing and Financing Items [Abstract]
Property and equipment in accounts payable	9	29
Offering costs in accounts payable and accrued expenses	37	444
Reduction of warrant liability upon cashless exercise of warrants	0	41
Reduction of accrued interest payable upon cashless exercise of promissory notes	0	3
Reduction in derivative liability upon cashless exercise of promissory notes	0	6
Cashless exercise of promissory notes	0	85
Dividend paid in-kind to preferred stockholders	336	264
Deemed dividend on preferred stock	$ 513	$ 4,099

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Statement of Cash Flows [Abstract]
Stock issuance costs	$ 1,170

Business and Organization

Business and Organization	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Organization	Business and Organization Organization Fibrocell Science, Inc. (as used herein, “we,” “us,” “our,” “Fibrocell” or the “Company”) is the parent company of Fibrocell Technologies, Inc. (Fibrocell Tech). Fibrocell Tech is the parent company of Isolagen International, S.A., a company organized under the laws of Switzerland (Isolagen Switzerland). The Company’s international activities are currently immaterial. Business Overview Fibrocell is an autologous cell and gene therapy company translating personalized biologics into medical breakthroughs. The Company is focused on discovering and developing therapies for the localized treatment of diseases affecting the skin and connective tissue. All of the Company’s product candidates incorporate its proprietary autologous fibroblast technology. The Company’s research and development efforts focus on gaining regulatory approvals of its product candidates in the United States. Liquidity and Financial Condition The Company expects to continue to incur losses and will require additional capital to advance its product candidates through development to commercialization. For the year ended December 31, 2018, the Company incurred a net loss of approximately $10.3 million , had an accumulated deficit of $189.1 million and used approximately $12.7 million in cash for operations. As of December 31, 2018, the Company had cash and cash equivalents of approximately $14.4 million and working capital of approximately $12.4 million . The Company believes that its cash and cash equivalents at December 31, 2018, will be sufficient to fund operations into the fourth quarter of 2019. The Company will require additional capital to fund operations beyond that point. To meet its capital needs, the Company intends to raise additional capital through debt or equity financings, collaborations, partnerships or other strategic transactions. However, there can be no assurance that the Company will be able to complete any such transaction on acceptable terms or otherwise. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company’s business, results of operations and financial condition. These conditions raise substantial doubt about its ability to continue as a going concern. The accompanying consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. On January 23, 2018, the Company received notice (the Notice) from the Nasdaq Capital Market (Nasdaq) that it was not in compliance with Nasdaq Listing Rule 5550(a)(2), as the minimum bid price of the Company’s common stock had been below $1.00 per share for 30 consecutive business days. On May 24, 2018, the Company implemented a one-for-five reverse split of its issued and outstanding shares of the Company’s common stock (the 2018 Reverse Stock Split), as authorized at the annual meeting of stockholders on May 23, 2018. The 2018 Reverse Stock Split became effective on May 24, 2018 at 5:00 pm and the Company’s common stock began trading on Nasdaq on a post-split basis at the open of business on May 25, 2018. As a result of the 2018 Reverse Stock Split, every five shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2018 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2018 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2018 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on Nasdaq. On June 11, 2018, the Company received written notice from Nasdaq notifying the Company that the closing bid price for the Company's common stock had been at $1.00 per share or greater for a minimum of ten consecutive business days and accordingly, the Company had regained compliance with Nasdaq Listing Rule 5550(a)(2). All share and per share amounts of common stock, options and warrants in the accompanying financial statements and related footnotes, have been restated for all periods to give retroactive effect to the 2018 Reverse Stock Split. Accordingly, the Condensed Consolidated Statement of Stockholders’ Equity reflects the impact of the 2018 Reverse Stock Split by reclassifying from “Common Stock” to “Additional paid in capital” an amount equal to the par value of the decreased shares resulting from the 2018 Reverse Stock Split. Nasdaq has the authority, pursuant to Nasdaq Listing Rule 5550(b)(1), to delist the Company’s common stock if its stockholders’ equity falls below $2.5 million . As of December 31, 2018, the Company’s stockholders’ equity was $9.6 million . If the Company’s stockholders equity is hereafter reduced below $2.5 million as a result of operating losses or for other reasons, the Company will fail to meet Nasdaq’s stockholders’ equity requirement. If that occurs, or if the Company is unable to demonstrate to Nasdaq’s satisfaction that it will be able to sustain compliance with this requirement, Nasdaq may delist the Company’s common stock. In addition, even if the Company regains technical compliance with the stockholders’ equity requirement, the Company will have to continue to meet other objective and subjective listing requirements to continue to be listed on the Nasdaq Capital Market, including the requirement that our common stock continues to trade above $1.00 . The Company is actively monitoring its stockholders’ equity and will consider any and all options available to it to maintain compliance. There can be no assurance, however, that the Company will be able to maintain compliance and meet Nasdaq’s minimum stockholders’ equity requirements.

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation General The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include the accounts of Fibrocell and its wholly owned subsidiaries. The accompanying Consolidated Financial Statements should be read in conjunction with the Notes to the Consolidated Financial Statements. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s foreign operations are immaterial and it has no unrealized gains or losses from the sale of investments. As a result, it does not have any items that would be classified as other comprehensive income in such a statement. Reclassifications On May 24, 2018, the Company implemented the 2018 Reverse Stock Split, as authorized at the annual meeting of stockholders on May 23, 2018. The 2018 Reverse Stock Split became effective on May 24, 2018 at 5:00 pm and the Company’s common stock began trading on Nasdaq on a post-split basis at the open of business on May 25, 2018. As of a result of the 2018 Reverse Stock Split, every five shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2018 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2018 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2018 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on Nasdaq. By letter dated June 11, 2018, The Nasdaq Capital Market Listing Qualification Department, confirmed that the Company’s common stock was in compliance with listing requirements. On March 10, 2017, the Company implemented a one-for-three reverse split of its issued and outstanding shares of common stock (the 2017 Reverse Stock Split and together with the 2018 Reverse Stock Split, the Reverse Stock Splits), as authorized at a special meeting of stockholders on March 1, 2017. The 2017 Reverse Stock Split became effective on March 10, 2017 at 5:00 pm and the Company’s common stock began trading on Nasdaq on a post-split basis at the open of business on March 13, 2017. As a result of the 2017 Reverse Stock Split, every three shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2017 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2017 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2017 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on Nasdaq. By letter dated March 27, 2017, The Nasdaq Capital Market Listing Qualification Department, confirmed that the Company’s common stock was in compliance with listing requirements. All share and per share amounts of common stock, options and warrants in the accompanying financial statements have been restated for all periods to give retroactive effect to the Reverse Stock Splits. Accordingly, the Consolidated Statement of Stockholders’ Equity reflects the impact of the Reverse Stock Splits by reclassifying from “Common Stock” to “Additional paid-in capital” an amount equal to the par value of the decreased shares resulting from the Reverse Stock Splits.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosure of contingencies in the accompanying Consolidated Financial Statements and Notes. In addition, management’s assessment of the Company’s ability to continue as a going concern involves the estimation of the amount and timing of future cash inflows and outflows. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable. Actual results may differ materially from those estimates. Segment Information The Company has determined that it operates in only one segment, as it only reports operational results on an aggregate basis to its chief operating decision maker, the Company’s President and Chief Executive Officer. Additionally, all of the Company’s research and development activities occur in, and assets are located in, the United States. Cash and Cash Equivalents The Company considers highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are limited to the Company’s cash and cash equivalents. As of December 31, 2018, the Company maintains its operating cash with one major U.S. domestic bank and the remainder of its cash and cash equivalents as a money market fund with one major global bank. Federal insurance coverage on operating cash amounted to $250,000 per depositor at each financial institution, and the Company’s non-interest bearing cash balances may exceed federally insured limits. The terms of these deposits are on demand to minimize risk. The Company has not incurred losses related to these deposits. Property and Equipment Property and equipment is carried at acquisition cost less accumulated depreciation, subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable as described further under the heading “Impairment of Long-lived Assets” below. The cost of normal, recurring, or periodic repairs and maintenance activities related to property and equipment are expensed as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if the repair will result in future economic benefits. Depreciation is computed on a straight-line basis over the estimated useful life of the respective assets, which are summarized as follows: Property and equipment category Useful life Computer equipment and software 3 years Laboratory equipment 6 years Furniture and fixtures 10 years Leasehold improvements Lesser of remaining lease term or life of asset When an asset is disposed of, the associated cost and accumulated depreciation is removed from the related accounts on the Company’s Consolidated Balance Sheet with any resulting gain or loss included in the Company’s Consolidated Statement of Operations. Impairment of Long-Lived Assets In accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 360-10-35, Impairment or Disposal of Long-Lived Assets , the Company reviews its long-lived assets and identifiable finite-lived intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable (i.e. impaired). Once an impairment is determined, the actual impairment recognized would be the difference between the carrying amount and the fair value (less any costs for disposal). The Company uses the following approaches to determine fair value: income, cost and/or market. Fair value using the income approach is determined primarily using a discounted cash flow model that uses the estimated cash flows associated with the asset or asset group under review, discounted at a rate commensurate with the risk involved. Fair value utilizing the cost approach is determined based on the replacement cost of the asset reduced for, among other things, depreciation and obsolescence. Fair value, utilizing the market approach, benchmarks the fair value against the carrying amount. Warrant Liability The Company accounts for stock warrants as either equity instruments, derivative liabilities, or liabilities in accordance with ASC 480, Distinguishing Liabilities from Equity (ASC 480), depending on the specific terms of the warrant agreement. Stock warrants are accounted for as a derivative in accordance with ASC 815, Derivatives and Hedging (ASC 815) if the stock warrants contain terms that could potentially require “net cash settlement” and therefore, do not meet the scope exception for treatment as a derivative. Warrant instruments that could potentially require “net cash settlement” in the absence of express language precluding such settlement are initially classified as derivative liabilities at their estimated fair values, regardless of the likelihood that such instruments will ever be settled in cash. The Company will continue to classify the fair value of the warrants that contain “net cash settlement” as a liability until the warrants are exercised, expire or are amended in a way that would no longer require these warrants to be classified as a liability. Warrants that the Company may be required to redeem through payment of cash or other assets outside its control are classified as liabilities pursuant to ASC 480 and are initially and subsequently measured at their estimated fair values. For additional discussion on warrants, see Note 7. Debt Issued With Warrants The Company considers guidance within ASC 470-20, Debt (ASC 470), ASC 480, and ASC 815 when accounting for the issuance of convertible debt with detachable warrants. As described above under the caption “ Warrant Liability ”, the Company classifies stock warrants as either equity instruments, derivative liabilities, or liabilities depending on the specific terms of the warrant agreement. In circumstances in which debt is issued with liability-classified warrants, the proceeds from the issuance of convertible debt are first allocated to the warrants at their full estimated fair value and established as both a liability and a debt discount. The remaining proceeds, as further reduced by discounts created by the bifurcation of embedded derivatives and beneficial conversion features, are allocated to the debt. The Company accounts for debt as liabilities measured at amortized cost and amortizes the resulting debt discount from the allocation of proceeds, to interest expense using the effective interest method over the expected term of the debt instrument pursuant to ASC 835, Interest (ASC 835). Embedded Derivatives. The Company considers whether there are any embedded features in debt instruments that require bifurcation and separate accounting as derivative financial instruments pursuant to ASC 815. Embedded derivatives are initially and subsequently measured at fair value. See Note 6 for additional discussion on the embedded derivatives associated with the Company’s convertible notes. Beneficial Conversion Feature. If the amount allocated to the convertible debt results in an effective per share conversion price less than the fair value of the Company’s common stock on the commitment date, the intrinsic value of this beneficial conversion feature is recorded as a discount to the convertible debt with a corresponding increase to additional paid in capital. The beneficial conversion feature discount is equal to the difference between the effective conversion price and the fair value of the Company’s common stock at the commitment date, unless limited by the remaining proceeds allocated to the debt. See Note 6 for additional discussion on the beneficial conversion feature associated with the Company’s convertible notes. Debt Issuance Costs. The Company follows the guidance under Accounting Standards Update (ASU) 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs (ASU 2015-03) for accounting for debt issuance costs. The Company allocates debt issuance costs between the debt and the warrants on the same basis as proceeds were allocated. The Company expenses issuance costs allocated to the warrants and presents the issuance costs allocated to the debt as a direct reduction from the carrying amount of the debt liability in the balance sheet. However, if debt issuance costs exceed the carrying amount of the debt, issuance costs are recorded to additional paid-in capital as a reduction of the beneficial conversion feature. As of December 31, 2018, the Company’s debt issuance costs are presented in additional paid-in capital as a reduction of the beneficial conversion feature and are being amortized to interest expense (despite their classification in additional paid-in capital) using the effective interest rate method over the expected term of the debt pursuant to ASC 835. Research and Development Expenses Research and development costs are expensed as incurred and include employee salaries and benefits, costs incurred with third party contractors to perform research, conduct clinical trials, develop and manufacture drug materials and delivery devices, and a portion of facilities costs. Research and development expenses also include costs to manufacture product for clinical trial use and to develop manufacturing, cell collection and logistical process improvements. Clinical trial costs are a significant component of research and development expenses, often with third party service providers. Invoicing from third party contractors for services performed can lag several months. The Company accrues the costs of services rendered in connection with third party contractor activities based on its estimate of management fees, site management and monitoring costs and data management costs incurred in a given period. Stock-Based Compensation The Company follows ASC 718, Compensation – Stock Compensation (ASC 718), or ASC 505-50, Equity – Equity Based Payments to Non-Employees, where applicable. The Company accounts for stock-based awards to employees using the fair value based method to determine compensation for all arrangements where shares of stock or equity instruments are issued for compensation. In addition, the Company accounts for stock-based compensation to non-employees in accordance with the accounting guidance for equity instruments that are issued to entities or persons other than employees. The Company uses a Black-Scholes option-pricing model to determine the fair value of each option grant as of the date of grant for expense incurred. The Black-Scholes option pricing model requires inputs for risk-free interest rate, dividend yield, expected stock price volatility and expected term of the options. The value of the award vests based on the achievement of the requisite service period. The expense is recognized on a straight line basis. See Note 10 for additional details. The Company considered the guidance in ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09) , which allows an entity to elect as an accounting policy either to continue to estimate the total number of awards for which the requisite service period will not be rendered or to account for forfeitures when they occur. In connection with the adoption of this ASU, the Company made an accounting policy election to account for forfeitures as they occur. Income Taxes An asset and liability approach is used for financial accounting and reporting for income taxes. Deferred income taxes arise from temporary differences between income tax and financial reporting and principally relate to recognition of revenue and expenses in different periods for financial and tax accounting purposes and are measured using currently enacted tax rates and laws. In addition, a deferred tax asset can be generated by a net operating loss carryover. If it is more likely than not that some portion or all of a deferred tax asset will not be realized, a valuation allowance is recognized. In the event the Company is charged interest or penalties related to income tax matters, the Company would record such interest as interest expense and would record such penalties as other expense in the Consolidated Statements of Operations. No such charges have been incurred by the Company. For each of the years ended December 31, 2018 and 2017, the Company had no uncertain tax positions. See Note 11 for additional details. Loss Per Share Data Basic loss per share is computed by dividing net loss for the period by the weighted average number of shares of common stock outstanding during that period. The diluted loss per share calculation gives effect to dilutive stock options, warrants, convertible notes and other potentially dilutive common stock equivalents outstanding during the period. Diluted loss per share is based on the if-converted method or the treasury stock method, as applicable, and includes the effect from the potential issuance of common stock, such as shares issuable pursuant to the conversion of convertible notes and the exercise of stock options and warrants, assuming the exercise of all “in-the-money” common stock equivalents based on the average market price during the period. Common stock equivalents have been excluded where their inclusion would be anti-dilutive. See Note 13 for additional details. Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) and rules are issued by the Securities and Exchange Commission (SEC) that we adopt as of the specified date. Unless otherwise noted, management does not believe that any other recently issued accounting pronouncements issued by the FASB or guidance issued by the SEC had, or is expected to have, a material impact on the Company’s present or future consolidated financial statements. In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718).” ASU 2018-07 simplifies the accounting for nonemployee share-based payment transactions. This ASU is effective for public entities for interim and annual reporting periods beginning after December 15, 2018. The Company has evaluated the potential impact of this guidance and does not believe that it will have a material impact on the Company’s financial statements. In July 2017, the FASB issued ASU No. 2017-11, “Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480) and Derivatives and Hedging (Topic 815): Part 1 - Accounting for Certain Financial Instruments with Down Round Features and Part 2 - Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with Scope Exception.” Part 1 of ASU No. 2017-11 addresses the complexity of accounting for certain financial instruments with down round features. Down round features are features of certain equity-linked instruments (or embedded features) that result in the strike price being reduced on the basis of the pricing of future equity offerings. Current accounting guidance creates cost and complexity for entities that issue financial instruments (such as warrants and convertible instruments) with down round features that require fair value measurement of the entire instrument or conversion option. Part II of ASU No. 2017-11 addresses the difficulty of navigating Topic 480, Distinguishing Liabilities from Equity, because of the existence of extensive pending content in the FASB Accounting Standards Codification®. This pending content is the result of the indefinite deferral of accounting requirements about mandatorily redeemable financial instruments of certain nonpublic entities and certain mandatorily redeemable noncontrolling interests. For public business entities, the amendments in Part I of this update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The amendments in Part II of this update do not require any transition guidance because those amendments do not have an accounting effect. The Company currently does not have any outstanding financial instruments with down round provisions, and therefore the impact of the adoption of this standard on its Consolidated Financial Statements, will not be material. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under the new guidance, lessees (including lessees under both leases classified as finance leases, which are to be classified based on criteria similar to that applicable to capital leases under current guidance, and leases classified as operating leases) will recognize a right-to-use asset and a lease liability on the balance sheet, initially measured as the present value of lease payments under the lease. Under current guidance, operating leases are not recognized on the balance sheet. The standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition approach for leases with an option to elect a package of practical expedients. Further, companies can elect to apply the transition approach either for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements or those existing at, or entered into after, the adoption date. The Company adopted the new standard effective January 1, 2019 and will not restate comparative periods. Presentation of leases within the consolidated statements of operations and consolidated statements of cash flows will be generally consistent with the current lease accounting guidance. The Company will elect the package of practical expedients permitted under the transition guidance and as such, the adoption of Topic 842 will not change the classification of any of its leases. The Company will elect to combine lease and non-lease components, elect not to record leases with an initial term of 12 months or less on the balance sheet and will recognize the associated lease payments in the consolidated statements of operations on a straight-line basis over the lease term. While the Company is currently assessing the full impact this ASU will have on its Consolidated Financial Statements, management believes the primary impact upon adoption will be the recognition, on a discounted basis, of its minimum commitments under the current non-cancellable operating lease, as amended, for its Exton, PA facility. The impact may result in the recording of right of use assets and lease obligations. The Company does not anticipate any other material impacts to its Consolidated Financial Statements.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment consisted of the following as of: December 31, ($ in thousands) 2018 2017 Laboratory equipment $ 1,562 $ 1,514 Computer equipment and software 319 318 Furniture and fixtures 44 44 Leasehold improvements 1,449 1,412 Construction-in-process 159 101 Total property and equipment, gross 3,533 3,389 Less: Accumulated depreciation (2,311 ) (1,919 ) Total property and equipment, net $ 1,222 $ 1,470 Depreciation expense was approximately $0.4 million for each of the years ended December 31, 2018 and 2017.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consisted of the following as of: December 31, ($ in thousands) 2018 2017 Accrued professional fees $ 281 $ 322 Accrued compensation 449 462 Accrued clinical trial expenses 525 342 Accrued other 215 134 Total accrued expenses $ 1,470 $ 1,260

Convertible Notes

Convertible Notes	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Convertible Notes	Convertible Notes 2016 Private Placement In September 2016, the Company issued an aggregate of $18,087,500 in principal of convertible promissory notes (each, a Note and collectively, the Notes) and accompanying warrants to purchase an aggregate of 1,205,840 shares of common stock (each a Warrant and collectively, the Warrants) in a private placement (the 2016 Private Placement) to institutional and accredited investors (each an Investor and collectively, the Investors). The Notes bear interest at four percent ( 4% ) per annum. Interest is earned daily and compounded quarterly and, at the election of the Company at the beginning of each quarter, shall accrue or be paid in cash. If the Company elects to have interest accrue, such interest will not be added to the principal amount of the Notes but such interest shall be subject to additional interest at the rate of four percent ( 4% ) per annum, compounded quarterly, and shall be due and payable upon the earliest of the conversion of the Notes, exercise of the Put Right, exercise of the Prepayment Right or the Maturity Date (in each case, as defined below). Additionally, if the Company elects for interest to accrue, then (i) the Company may elect to repay any such accrued and unpaid interest in cash at any time and from time to time and (ii) each Investor may elect to have the Company repay any such accrued and unpaid interest by delivering such number of shares of common stock equal to (x) the amount of the accrued and unpaid interest to be repaid, divided by (y) the greater of (i) the last closing bid price of a share of the Company’s common stock as reported on Nasdaq on the date of such election and (ii) the Conversion Price (as defined below). As of December 31, 2018, the Company has elected to accrue interest. All unpaid principal of each Investor’s Note is convertible, at any time and from time to time, at the option of such Investor into shares of common stock at a range of $17.04375 to $18.39375 (the “conversion price”), and any unpaid interest at the greater of (x) the conversion price and (y) the last closing bid price of a share of common stock as reported on Nasdaq at the time of such Investor’s execution of the Agreement for the Purchase and Sale of Convertible Debt and Common Stock Warrants plus $0.12625 . The Notes have a maturity date of the earlier of (i) September 7, 2026 and (ii) one-hundred and eighty ( 180 ) days after the date on which the Company’s product candidate, FCX-007, is approved by the United States Food and Drug Administration for the treatment of recessive dystrophic epidermolysis bullosa (the Maturity Date). Each Investor has the right to require the Company to repay all or any portion of the unpaid principal and accrued and unpaid interest from time to time on or after September 7, 2021 (such right, a Put Right). Such Put Right must be exercised by such Investor by delivering written notice to the Company no later than one-hundred and eighty ( 180 ) days prior to such exercise date of such Put Right. In addition, upon consummation of a specified change of control transaction, each Investor may elect to accelerate the repayment of all unpaid principal and accrued interest under such Investor’s Note. If an Investor does not elect to have the Company prepay its Note upon such change of control transaction, then the Company may prepay the Notes, in an amount equal to one hundred one percent ( 101% ) of the outstanding principal due under the Notes (together with accrued and unpaid interest due thereon) (the Prepayment Right). Additionally, upon the occurrence of certain Events of Default, as defined in the Notes, each Investor may elect to accelerate the repayment of all unpaid principal and accrued interest under each Note and the Notes provide for automatic redemption upon the occurrence of certain bankruptcy related Events of Default, as defined in the Notes. Accounting for Convertible Notes and Embedded Derivatives The Company accounts for debt as liabilities measured at amortized cost and amortizes the resulting debt discount from allocation of proceeds to interest expense using the effective interest method over the expected term of the Notes pursuant to ASC 835, Interest (ASC 835). See Note 3 for discussion of the Company’s policies for accounting for debt with detachable warrants. In connection with the issuance of the Notes and Warrants, the Company recorded a debt discount of approximately $18.1 million based on an allocation of proceeds to the Warrants of approximately $9.6 million , an allocation to bifurcated derivatives (which consist of a contingent put option upon a change of control or acceleration upon event of default (the Contingent Put Option) and a contingent call option upon a change of control (the Contingent Call Option) included in the Notes) of approximately $1.3 million, and a beneficial conversion feature of approximately $7.2 million , before issuance costs, based on the difference between the fair value of the underlying common stock at the commitment date of each Note transaction and the effective conversion price of the Notes, as limited by the proceeds allocated to the Notes. Convertible promissory notes outstanding were as follows: ($ in thousands) December 31, 2018 2017 Convertible promissory notes $ 18,003 $ 18,003 Debt discount - warrants (9,598 ) (9,598 ) Debt discount - compound bifurcated derivatives (1,267 ) (1,267 ) Debt discount - beneficial conversion feature (7,138 ) (7,138 ) Convertible promissory notes, net $ — $ — The debt discount and issuance costs are amortized using the effective interest method over five years , the expected term of the Notes. Amortization of the debt discounts included in interest expense in the Consolidated Statement of Operations for the year ended December 31, 2018 and December 31, 2017 was approximately $0 and $0.1 million . Based on an effective yield of approximately 1157% resulting from the Notes being initially recorded at a full discount, the Company will not recognize any material amounts of amortization until years 2020 and 2021. The amortization of debt discount recorded in the year ended December 31, 2017 was related to the conversion of notes into shares. Assumptions Used in Determining Fair Value of Compound Bifurcated Derivative The Company utilizes a binomial lattice model to value its bifurcated derivatives included in the Notes. ASC 815 does not permit an issuer to account separately for individual derivative terms and features embedded in hybrid financial instruments that require bifurcation and liability classification as derivative financial instruments. Rather, such terms and features must be combined together and fair valued as a single, compound embedded derivative. The Company selected a binomial lattice model to value the compound embedded derivative because it believes this technique is reflective of all significant assumptions that market participants would likely consider in negotiating the transfer of the Notes. Such assumptions include, among other inputs: Volatility. The Company estimates stock price volatility based on the Company’s historical stock price performance over a period of time that matches the volume-weighted average expected remaining life of the Notes. Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury zero-coupon yield curve in effect at the valuation date commensurate with the expected remaining life assumption. Expected remaining life. The expected life of the Notes is assumed to be equivalent to their remaining contractual term. Dividend rate. The dividend rate is based on the historical rate, which the Company anticipates will remain at zero . Scenarios. The probability of complex features of the compound bifurcated derivative being triggered is subjective (no observable inputs or available market data) and based on internal and external information known to management at the valuation date. Such assumptions include, among other inputs, probabilities related to a change of control and when it might occur as well as probabilities related to a default under the provisions of the Notes and when it might occur. Changes to the key assumptions or to the scenarios used in the valuation model, including the probability of key events, such as a change of control transaction, and the credit spread could have a material impact to the overall valuation of the compound bifurcated derivative liability. A 5% change to the probability of a change of control event occurring in 2019 and 2020 would impact the derivative fair value by approximately $0.3 million and $0.1 million , respectively. A 5% change in the estimated credit spread would impact the derivative fair value by approximately $0.1 million . The sensitivity examples provided are included for illustrative purposes only and do not reflect the changes in these assumptions used by the Company. Changes in excess of those illustrated may occur in any period. The estimated fair value of the compound bifurcated derivative is determined using Level 2 and Level 3 inputs. Significant inputs and assumptions used in the binomial lattice model for the derivative liability are as follows: ($ in thousands except per share data) December 31, 2018 December 31, 2017 Calculated aggregate value $ 1,474 $ 3,136 Closing price per share of common stock $ 1.50 $ 3.20 Contractual remaining term 7 years, 8 months 8 years, 8 months Contractual interest rate 4.0 % 4.0 % Volume-weighted average conversion rate $ 17.04667 $ 17.04667 Risk-free interest rate (term structure) 2.44% - 2.69% 1.28% - 2.40% Dividend yield — — Credit Rating CC CC Credit Spread 31.77 % 36.98 % Volatility 87.5 % 99.0 % The foregoing compound bifurcated derivative was recorded at its estimated fair value at the date of issuance, with subsequent changes in estimated fair value recorded in derivative revaluation expense in the Company’s Consolidated Statement of Operations. The change in estimated fair value of the Company’s derivative liability for the years ended December 31, 2018 and December 31, 2017, resulted in non-cash income (expense) of approximately $1.7 million and $(1.4) million respectively.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Warrants	Warrants The Company accounts for common stock warrants as equity instruments, derivative liabilities, or liabilities, depending on the specific terms of the warrant agreement. See Note 3 for further details on accounting policies related to the Company’s stock warrants. In connection with various financing transactions, the Company has issued warrants to purchase the Company’s common stock. In July 2018, in connection with a private placement (the July 2018 Private Placement), the Company issued unregistered warrants to purchase 958,152 shares of its common stock. Each common stock purchase warrant has an exercise price of $2.70 per share, was exercisable upon the date of issuance and expires five and one-half years from the date of the issuance. In addition, the Company also issued unregistered warrants to purchase up to an aggregate of 103,186 shares of its common stock to the designees of H.C. Wainwright & Co., LLC (HCW), as partial compensation for placement agent services by HCW in connection with the Company’s registered direct public offering in July 2018 (the July 2018 Registered Direct Public Offering), and the July 2018 Private Placement. Such unregistered warrants have an initial exercise price of $3.464 per share are immediately exercisable and expire on July 3, 2023. In May 2018, in connection with a private placement (the May 2018 Private Placement), the Company issued unregistered warrants to purchase 1,528,668 shares of its common stock. Each common stock purchase warrant has an exercise price of $2.86 per share, was exercisable upon the date of the issuance and expires five and one-half years from the date of the issuance. The Company also issued unregistered warrants to purchase up to an aggregate of 142,676 shares of its common stock to the designees of HCW, as partial compensation for placement agent services by HCW in connection with the Company’s registered direct public offering in May 2018 (the May 2018 Registered Direct Public Offering), and the May 2018 Private Placement. Such unregistered warrants have an initial exercise price of $3.679 per share are immediately exercisable and expire on May 30, 2023. In July 2018, the Company filed a registration statement on Form S-1 (the Resale Registration Statement) registering the resale of shares of the Company’s common stock underlying warrants issued in the May 2018 Private Placement and the July 2018 Private Placement. The Resale Registration Statement was declared effective by the SEC on August 8, 2018. In December 2017, the Company issued (i) pre-funded warrants to purchase an aggregate of 1,184,422 shares of the Company’s common stock and (ii) common stock purchase warrants to purchase up to an aggregate of 2,809,404 shares of the Company’s common stock including warrants to purchase up to 82,118 shares, issued pursuant to the partial exercise of the underwriters option to purchase additional common stock purchase warrants. Each pre-funded warrant was sold together with a common stock purchase warrant to purchase one share of the Company’s common stock at a combined effective price of $3.85 per share and accompanying warrant. Each common stock purchase warrant has an exercise price of $3.85 per share, was exercisable upon the date of issuance and expires five years from the date of issuance. As additional compensation, the Company issued warrants to the underwriter to purchase 87,274 shares of the Company’s common stock. Each such warrant has an exercise price of $4.8125 per share, and was exercisable as of the date of the underwriting agreement, and will expire five years after the date of the underwriting agreement, all as more fully described in Note 8. In March 2017, the Company issued warrants to purchase 687,468 shares of its common stock in connection with the Company’s public offering of convertible preferred stock and warrants (each a Series A Warrant and collectively, the Series A Warrants), more fully described in Note 8. Each warrant has an exercise price of $12.69 , was exercisable six months after the date of issuance and will expire five years from the date of issuance. In September 2016, the Company issued warrants to purchase 1,205,840 shares of its common stock for an exercise price of $22.50 per share to investors in connection with a private placement of convertible debt securities as more fully discussed in Note 6. The warrants are exercisable at any time beginning six months after issuance through five years after issuance. The Company classified these warrants as liabilities based on the guidance in ASC 480, as the warrants contain a provision that could result in the Company’s redemption of the warrants outside its control for cash equal to the value of the warrants calculated using a Black-Scholes option pricing model. The following table summarizes the Company’s outstanding warrants to purchase common stock as of: Number of Warrants December 31, 2018 December 31, 2017 Exercise Price Expiration Dates Liability-classified Warrants Issued with June 2012 Convertible Notes — 75,040 $ 37.50 Jun 2018 Issued in Series E Preferred Stock offering — 104,676 $ 112.50 Dec 2018 Issued with September 2016 Convertible Notes 1,205,840 1,205,840 $ 22.50 Sept 2021 1,205,840 1,385,556 Equity-classified Warrants Issued in 2017 Series A Preferred Stock Offering 687,468 687,468 $ 12.69 Mar 2022 Issued in 2017 Common Stock Offering - common warrants 2,679,702 2,809,404 $ 3.85 Dec 2022 Issued in 2017 Common Stock Offering - underwriter warrants 87,274 87,274 $ 4.8125 Dec 2022 Issued in 2017 Common Stock Offering - pre-funded warrants — 483,221 $ 0.05 No expiration Issued in May 2018 Private Placement - common warrants 1,528,668 — $ 2.86 Nov 2023 Issued in May 2018 Registered Direct Offering - underwriter warrants 142,676 — $ 3.679 May 2023 Issued in July 2018 Private Placement - common warrants 958,152 — $ 2.70 Jan 2024 Issued in July 2018 Registered Direct Offering - underwriter warrants 103,186 — $ 3.464 Jul 2023 6,187,126 4,067,367 Total outstanding warrants 7,392,966 5,452,923 The table below is a summary of the Company’s warrant activity for the year ended December 31, 2018. Number of warrants Liability-classified Equity-classified Total Weighted-average exercise price Outstanding at December 31, 2017 1,385,556 4,067,367 5,452,923 $ 11.32 Granted — 2,732,682 2,732,682 2.87 Exercised — (612,923 ) (612,923 ) 0.85 Expired (179,716 ) — (179,716 ) 81.18 Outstanding at December 31, 2018 1,205,840 6,187,126 7,392,966 $ 7.36 Accounting for Liability-classified Warrants The foregoing warrants are recorded as liabilities at their estimated fair value at the date of issuance, with subsequent changes in estimated fair value recorded in warrant revaluation income in the Company’s Consolidated Statement of Operations in each subsequent period. The change in estimated fair value of the Company’s warrant liability for the years ended December 31, 2018 and 2017 resulted in non-cash income of $0.9 million and $4.9 million, respectively. Additionally, the warrants are classified as either current or non-current on the Company’s Consolidated Balance Sheet based on their contractual expiration date. The Company utilizes the Monte Carlo simulation valuation method to value its liability-classified warrants. Assumptions Used in Determining Fair Value of Warrants The estimated fair value of warrants is determined using Level 2 and Level 3 inputs which is further discussed in Note 9. Inherent in the Monte Carlo simulation valuation method are the following assumptions: Volatility. The Company estimates stock price volatility based on the Company’s historical stock price performance over a period of time that matches the volume-weighted average expected remaining life of the warrants. Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury zero-coupon yield curve in effect at the valuation date commensurate with the expected remaining life assumption. Expected remaining life. The expected life of the warrants is assumed to be equivalent to their remaining contractual term. Dividend rate. The dividend rate is based on the historical rate, which the Company anticipates will remain at zero. Scenarios. The probability of complex features of the warrants being triggered is subjective (no observable inputs or available market data) and based on internal and external information known to management at the valuation date. Such assumptions include, among other inputs, probabilities related to a change of control and when it might occur as well as probabilities related to a default under the provisions of the Notes and when it might occur. Changes to the key assumptions or to the scenarios used in the valuation model, including the probability of key events, such as a change of control transaction, could have a material impact to the overall valuation of the warrant liability. The following table summarizes the calculated aggregate fair values, along with the assumptions utilized in each calculation: ($ in thousands, except per share data) December 31, December 31, Calculated aggregate value $ 152 $ 1,073 Weighted average exercise price per share $ 22.50 $ 30.10 Closing price per share of common stock $ 1.50 $ 3.20 Volatility 94.1 % 92.2 % Weighted average remaining expected life 2 years, 8 months 3 years, 4 months Risk-free interest rate 2.45 % 2.00 % Dividend yield — —

Equity

Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Equity	Equity Preferred Stock The Company is authorized to issue 5,000,000 shares of preferred stock, at a par value of $0.001 per share, in one or more series and to fix the rights, preferences, privileges, and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock. The issuance of the Company’s preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change of control of the Company or other corporate action. Series A Convertible Preferred Stock In March 2017, the Company’s Board of Directors (the Board) authorized the issuance of 8,000 shares of preferred stock designated as Series A Convertible Preferred Stock (the Series A Preferred Stock). The rights, preferences and privileges of the Series A Preferred Stock is set forth in the Certificate of Designation of Preferences, Rights and Limitations of Series A Convertible Preferred Stock dated March 7, 2017 (Certificate of Designation). On March 7, 2017, the Company entered into a securities purchase agreement with certain of its existing accredited investors pursuant to which the Company agreed to sell a total of 8,000 units (the Units) for a purchase price of $1,000 per Unit, with each Unit consisting of (i) one share of the Company’s Series A Preferred Stock, with an initial stated value of $1,000 and is convertible into 85 shares of the Company’s common stock with a conversion price of $11.6355 and (ii) a warrant to purchase up to the number of shares of common stock equal to 100% of the conversion shares issuable on March 7, 2017 pursuant to the shares of Series A Preferred Stock purchased by each investor (collectively, the 2017 Series A Preferred Stock Offering). The 2017 Series A Preferred Stock Offering closed on March 8, 2017 and resulted in gross proceeds of $8.0 million , before deducting offering costs. The proceeds from the 2017 Series A Preferred Stock Offering (including offering costs) were allocated between the Series A Warrants and Series A Preferred Stock issued in the transaction based upon their respective fair values using the relative fair value (proportional) method. The fair value of the Series A Preferred Stock issued was calculated as the sum of (i) the value of the Series A Preferred Stock as if it had been converted into common stock on the issuance date and (ii) the value of a perpetual annuity paying a 4% dividend rate in conversion shares for five years and 8% thereafter. In connection with the valuation, the following assumptions were used: risk free interest rate of 3.15% , credit spread of 31.27% and a market yield of 34.42% . The application of the relative fair value method resulted in an allocation of gross proceeds to the Series A Preferred Stock of approximately $1.3 million , net of discounts of $3.0 million attributed to the warrants (See Note 7) and $3.7 million from a beneficial conversion feature. The discount attributed to the beneficial conversion feature was immediately amortized as the Series A Preferred Stock has no stated redemption date and is convertible at the issuance date. For the years ended December 31, 2018 and 2017, the Company recognized approximately $0.5 million and $4.1 million , respectively, of amortization of the discount on the Series A Preferred Stock as deemed dividends charged to additional paid-in capital (in the absence of retained earnings). The value of the beneficial conversion feature is calculated as the difference between the effective conversion price of the Series A Preferred Stock and the fair market value of the common stock into which the Series A Preferred Stock are convertible at the commitment date. The discount attributed to the warrants is being accreted using the effective interest method and charged as a deemed dividend to additional paid-capital (in the absence of retained earnings), over the five -year period of the Series A Preferred Stock in which the stated dividend rate is 4% . For the years ended December 31, 2018 and 2017, the Company recognized approximately $0.5 million and $0.3 million , respectively, in deemed dividends due to the accretion of the warrant discount. The 2017 Series A Preferred Stock Offering securities purchase agreement contains customary representations, warranties, and agreements by the Company. The securities purchase agreement also contains customary prohibitions on certain Company payments, the incurrence of certain senior and pari passu debt, certain affiliate transactions and the incurrence of certain liens. Holders of the Series A Preferred Stock are entitled to receive cumulative dividends at a rate per share of 4% per annum (with such dividend rate increasing to 8% per annum on the five -year anniversary of the original issuance of the Series A Preferred Stock), with such dividends compounded quarterly and payable only by way by increasing the stated value of the Series A Preferred Stock in accordance with the terms of the Certificate of Designation. For the years ended December 31, 2018 and 2017, cumulative dividends paid in-kind to holders of the Series A Preferred Stock were approximately $0.3 million for both periods. Shares of Series A Preferred Stock generally have no voting rights, except as required by law; provided, however, that without the prior written consent of the holders of at least 70% of the then outstanding shares of Series A Preferred Stock, the Company may not: (i) alter or change adversely the powers, preferences or rights given to the Series A Preferred Stock or alter or amend the Certificate of Designation; (ii) amend the Company’s certificate of incorporation or other charter documents in any manner that adversely affects any rights of a holder of the Series A Preferred Stock; (iii) authorize or create any class of stock ranking as to redemption, distribution of assets upon liquidation or dividends senior to, or otherwise pari passu with, the Series A Preferred Stock; (iv) declare or make any dividends other than dividend payments or other distributions payable solely in the Company’s common stock; or (v) enter into any agreement with respect to any of the foregoing. Upon a liquidation, dissolution or winding up of the Company, the holders of the Series A Preferred Stock are entitled to receive out of the Company’s assets, whether capital or surplus, an amount equal to such holder’s then stated value for each share of Series A Preferred Stock before any distribution to the holders of the Company’s common stock, any class or series of preferred stock and all other common stock equivalents other than those securities which are explicitly senior or pari passu to the Series A Preferred Stock in redemption, distribution of assets upon a liquidation or dividends. If there are insufficient assets to pay in full such amounts, then the available assets will be ratably distributed to the holders of the Series A Preferred Stock in accordance with the respective amounts that would be payable on such shares if all amounts payable thereon were paid in full. Common Stock In July 2016, the Company amended its Restated Certificate of Incorporation, as amended, to increase the number of shares of common stock that the Company is authorized to issue from 100,000,000 to 150,000,000 . On May 24, 2018, the Company implemented the 2018 Reverse Stock Split, as authorized at the annual meeting of stockholders on May 23, 2018. The 2018 Reverse Stock Split became effective on May 24, 2018 at 5:00 pm and the Company’s common stock began trading on Nasdaq on a post-split basis at the open of business on May 25, 2018. As a result of the 2018 Reverse Stock Split, every five shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2018 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2018 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2018 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on The Nasdaq Capital Market. By letter dated. June 11, 2018, The Nasdaq Capital Market Listing Qualification Department, confirmed that the Company’s common stock was in compliance with listing requirements. On March 10, 2017, the Company implemented the 2017 Reverse Stock Split, as authorized at a special meeting of stockholders on March 1, 2017. The 2017 Reverse Stock Split became effective on March 10, 2017 at 5:00 pm and the Company’s common stock began trading on The Nasdaq Capital Market on a post-split basis at the open of business on March 13, 2017. As of a result of the 2017 Reverse Stock Split, every three shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2017 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2017 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2017 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on The Nasdaq Capital Market. By letter dated March 27, 2017, The Nasdaq Capital Market Listing Qualification Department, confirmed that the Company’s common stock was in compliance with listing requirements. December 2018 Private Placement On December 11, 2018, the Company completed the sale of 443,350 shares of its common stock (the December 2018 Private Placement), for approximately $0.9 million . After deducting offering expenses, net proceeds from the December 2018 Private Placement was approximately $0.8 million . July 2018 Registered Direct Offering and Private Placement On July 2, 2018, the Company entered into securities purchase agreements (July 2018 Purchase Agreements) with certain institutional and accredited investors for the sale by the Company of 1,474,080 shares of the Company’s common stock, par value $0.001 per share at a purchase price of $2.69 per share (the July 2018 Registered Direct Offering). Concurrently with the July 2018 Registered Direct Offering, and pursuant to the July 2018 Purchase Agreements, the Company also sold unregistered warrants exercisable for an aggregate of 958,152 shares of the Company’s common stock, which represents 65% of the shares of the Company’s common stock sold in the July 2018 Registered Direct Offering, for a purchase price of $0.125 per warrant and with an exercise price of $2.70 per share. Subject to certain ownership limitations, the warrants were exercisable upon issuance. The warrants will expire on the 5.5 years anniversary of the date of issuance. The July 2018 Registered Direct Offering and the July 2018 Private Placement closed on July 5, 2018. The net proceeds from the transactions were approximately $3.6 million after deducting certain fees due to the placement agent and other estimated transaction expenses. In addition, the placement agent received warrants to purchase 103,186 shares of the Company’s common stock. The warrants issued to the placement agent have substantially the same terms as the warrants issued in the July 2018 Private Placement, except that the exercise price of the warrants issued to the placement agent is $3.464 per share and the term of the warrants issued to the placement agent is five years. On July 27, 2018, the Company filed a registration statement on Form S-1, registering the resale of shares of the Company’s common stock underlying warrants issued in the May 2018 Private Placement and the July 2018 Private Placement. The Resale Registration Statement was declared effective by the SEC on August 8, 2018. May 2018 Registered Direct Offering and Private Placement On May 29, 2018, in connection with the May 2018 Registered Direct Offering, the Company entered into securities purchase agreements (May 2018 Purchase Agreements) with certain institutional and accredited investors for the sale by the Company of 2,038,224 shares of the Company’s common stock, par value $0.001 per share at a purchase price of $2.85 per share. Concurrently with the May 2018 Registered Direct Offering, and pursuant to the May 2018 Purchase Agreements, the Company in connection with the May 2018 Private Placement, also sold unregistered warrants exercisable for an aggregate of 1,528,668 shares of the Company’s common stock, which represents 75% of the shares of the Company’s common stock sold in the May 2018 Registered Direct Offering, for a purchase price of $0.125 per warrant and with an exercise price of $2.86 per share. Subject to certain ownership limitations, the warrants were exercisable upon issuance. The warrants will expire on the 5.5 years anniversary of the date of issuance. The May 2018 Purchase Agreements contain representations, warranties and covenants of the investors and the Company that are customary for transactions of this type. The May 2018 Registered Direct Offering and the May 2018 Private Placement closed on May 31, 2018. The net proceeds from the transactions were approximately $5.3 million after deducting certain fees due to the placement agent and other estimated transaction expenses. In connection with the May 2018 Registered Direct Offering and the May 2018 Private Placement, the placement agent received warrants to purchase up to 7.0% of the aggregate amount of shares of Company common stock sold in the May 2018 Registered Direct Offering. The warrants issued to the placement agent have substantially the same terms as the warrants issued in the May 2018 Private Placement, except that the exercise price of the warrants issued to the placement agent is $3.679 per share and the term of the warrants issued to the placement agent is five years. December 2017 Public Offering On December 7, 2017, the Company entered into an underwriting agreement (the Underwriting Agreement) with HCW, relating to the sale of 1,542,832 shares of its common stock, pre-funded warrants to purchase an aggregate of 1,184,422 shares of common stock and common warrants to purchase up to an aggregate of 2,809,404 shares of common stock (the Offering). Each share of common stock or pre-funded warrant, as applicable, was sold together with a common warrant to purchase one share of common stock at a combined effective price to the public of $3.85 per share and accompanying common warrant. At December 31, 2018, all of the pre-funded warrants had been exercised and converted to shares of common stock. Pursuant to the HCW Underwriting Agreement, the Company granted HCW a thirty day option, which option ended on January 6, 2018, to purchase up to 409,091 additional shares of the Company’s common stock at a purchase price of $3.80 per share and/or common warrants to purchase up to an aggregate of 409,091 shares of the Company’s common stock at a purchase price of $0.05 per common warrant with an exercise price of $3.85 per share, less the underwriting discounts and commissions. On December 8, 2017, HCW partially exercised this option by purchasing common warrants to purchase 82,118 shares of common stock. As additional compensation, the Company issued warrants to HCW to purchase 87,274 shares of common stock (the Underwriter Warrants). The Underwriter Warrants have an exercise price of $4.8125 per share, will be exercisable for five years from the date of the HCW Underwriting Agreement and may be exercised on a cashless basis in certain circumstances specified therein. The Company and HCW completed the Offering on December 11, 2017, resulting in approximately $9.3 million of net proceeds to the Company after deducting the underwriter’s discounts and commissions and other estimated offering expenses payable by the Company. The common warrants are exercisable immediately at an exercise price of $3.85 per share and will expire five years from the date of issuance. The pre-funded warrants are exercisable immediately at an exercise price of $0.05 per share and may be exercised until they are exercised in full. The Underwriter Warrants have an exercise price of $4.8125 per share and will expire five years from the date of the HCW Underwriting Agreement. The exercise price and number of shares of the Company’s common stock issuable upon exercise of the common warrants, pre-funded warrants and Underwriter Warrants will be subject to adjustment in the event of any stock split, reverse stock split, stock dividend, recapitalization, reorganization or similar transaction, among other events as described in the common warrants and pre-funded warrants. In the event of certain transactions involving a sale of the Company, each holder of common warrants has the right, exercisable at its option, to require the Company to purchase such holder’s common warrants at a price determined using a Black-Scholes option pricing model as described in the common warrants. The shares of common stock or pre-funded warrants, as applicable, and the accompanying common warrants could only be purchased together in this Offering but were issued separately.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company follows the guidance in ASC 820, Fair Value Measurement , to account for financial assets and liabilities measured on a recurring basis. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company uses a fair value hierarchy, which distinguishes between assumptions based on market data (observable inputs) and an entity’s own assumptions (unobservable inputs). The guidance requires fair value measurements be classified and disclosed in one of the following three categories: • Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; • Level 2: Quoted prices in markets that are not active or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability; • Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Determining which category an asset or liability falls within the hierarchy requires significant judgment. The Company evaluates its hierarchy disclosures each reporting period. There were no transfers between Level 1, 2 and 3 during each of the years ended December 31, 2018 and 2017. The following fair value hierarchy table presents information about each major category of the Company’s financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2017: December 31, 2018 ($ in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 12,290 $ — $ — $ 12,290 Total Assets $ 12,290 $ — $ — $ 12,290 Liabilities: Warrant liability $ — $ — $ 152 $ 152 Derivative liability — — 1,474 1,474 Total Liabilities $ — $ — $ 1,626 $ 1,626 December 31, 2017 ($ in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 14,670 $ — $ — $ 14,670 Total Assets $ 14,670 $ — $ — $ 14,670 Liabilities: Warrant liability $ — $ — $ 1,073 $ 1,073 Derivative liability — — 3,136 3,136 Total Liabilities $ — $ — $ 4,209 $ 4,209 Changes in Level 3 Liabilities Measured at Fair Value on a Recurring Basis Common Stock Warrants - Warrant Liability The reconciliation of the Company’s warrant liability measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows: ($ in thousands) Warrant Liability Balance at December 31, 2016 $ 6,034 Exercise of warrants (1) (41 ) Change in fair value of warrant liability (2) (4,920 ) Balance at December 31, 2017 $ 1,073 Change in fair value of warrant liability (2) (921 ) Balance at December 31, 2018 $ 152 (1) Warrants were exercised under the cashless exercise method pursuant to the corresponding warrant agreements. As a result of such exercises, the Company issued 6,941 shares of common stock. Consequently, these instruments were no longer classified as liabilities. These common stock warrants were remeasured to their fair value as of the exercise date with the change in fair value recorded to the Company’s Consolidated Statement of Operations. The fair value related to the shares issued in connection with the exercised warrants was reclassified from a liability to additional paid-in capital in the Company’s Consolidated Balance Sheets. (2) Includes the fair value as of the beginning of the year for warrants expiring during the year and has been recorded to warrant revaluation income in the Company’s Consolidated Statement of Operations for the respective year end. The fair value of the warrant liability is based on Level 3 inputs. For this liability, the Company developed its own assumptions that do not have observable inputs or available market data to support the fair value. See Note 7 for further discussion of the warrant liability. Bifurcated Compound Derivative - Derivative Liability The reconciliation of the derivative liability measured at fair value on a recurring basis using unobservable inputs (Level 3) was as follows: ($ in thousands) Derivative Liability Balance at December 31, 2016 $ 1,735 Derivative liability to equity upon note conversion (1) (6 ) Change in fair value of derivative liability 1,407 Balance at December 31, 2017 $ 3,136 Change in fair value of derivative liability (1,662 ) Balance at December 31, 2018 $ 1,474 (1) Convertible notes from the September 2016 Private Placement, were converted to shares of common stock pursuant to the corresponding convertible note agreements. As a result of such conversions, the Company issued 24,911 shares of common stock. Consequently, these instruments were no longer classified as liabilities. These embedded derivatives were remeasured to their fair value as of the exercise date with the change in fair value recorded to the Company’s Consolidated Statement of Operations. The fair value related to the shares issued in connection with the converted notes was reclassified from a liability to additional paid-in capital in the Company’s Consolidated Balance Sheets. Effect of the Company’s Stock Price and Volatility Assumptions on the Calculation of Fair Value of Financial Instruments Measured on a Recurring Basis Common Stock Warrants - Warrant Liability The fair value of the Company’s warrant liability is based on Level 3 inputs. As discussed in Note 7, the Company uses a Monte Carlo simulation valuation method to value its liability-classified warrants. The determination of fair value as of the reporting date is affected by the Company’s stock price as well as assumptions regarding a number of subjective variables that do not have observable inputs or available market data to support the fair value. These variables include, but are not limited to, expected stock price volatility over the term of the warrants and the risk-free interest rate. The primary factors affecting the fair value of the warrant liability are the Company’s stock price and volatility as well as certain assumptions by the Company as to the likelihood of provisions to the underlying warrant agreements being triggered. The methods described above and in Note 7 may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation method is appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value could result in a different fair value measurement at the reporting date. Bifurcated Compound Derivative - Derivative Liability The fair value of the derivative liability is based on Level 3 inputs. As discussed in Note 6, the Company uses a binomial lattice model to value the compound embedded derivative bifurcated from the Notes. The determination of fair value as of the reporting date is affected by the Company’s stock price as well as assumptions regarding a number of subjective variables that do not have observable inputs or available market data to support the fair value. These variables include, but are not limited to, expected stock price volatility, changes in interest rates, assumptions regarding the adjusted conversion prices in the Notes, and early redemption or conversion of the Notes. The methods described above and in Note 6 may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation method is appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value could result in a different fair value measurement at the reporting date. Fair Value of Certain Financial Assets and Liabilities The Company believes that the fair values of its current assets and liabilities approximate their reported carrying amounts. The fair value of the long-term convertible promissory notes was approximately $12.5 million at December 31, 2018, and $11.2 million at December 31, 2017, compared to a carrying value of $0 , as a result of unamortized debt discounts, for both periods.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2009 Equity Incentive Plan The Board adopted the 2009 Equity Incentive Plan (as amended to date, the Plan) effective September 3, 2009. The Plan is intended to further align the interests of the Company and its stockholders with its employees, including its officers, non-employee directors, consultants and advisers by providing equity-based incentives. The Plan allows for the issuance of up to 506,667 shares of the Company’s common stock. The types of awards that may be granted under the Plan include options (both non-qualified stock options and incentive stock options), stock appreciation rights, stock awards, stock units, and other stock-based awards. The term of each award is determined by the Compensation Committee of the Board at the time each award is granted, provided that the term of the option does not exceed ten years . Vesting schedules for stock options vary, but generally vest 25% per year, over four years for employee options and on the one -year anniversary date for non-employee director options. The Plan had 215,670 options available for grant as of December 31, 2018. Accounting for Stock-Based Compensation The Company recognizes non-cash compensation expense for stock-based awards based on their grant date fair value, determined using the Black-Scholes option-pricing model. During the years ended December 31, 2018 and 2017, the weighted average fair market value of options granted was $2.22 and $10.58 , respectively. Total stock-based compensation expense recognized using the straight-line attribution method and included in operating expenses in the Company’s Consolidated Statements of Operations was approximately $0.5 million and $0.3 million for the years ended December 31, 2018 and 2017, respectively. Assumptions Used in Determining Fair Value of Stock Options Inherent in the Black-Scholes option-pricing model are the following assumptions: Volatility. The Company estimates stock price volatility based on the Company’s historical stock price performance over a period of time that matches the expected term of the stock options. Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption. Expected term . The expected term of stock options granted is based on an estimate of when options will be exercised in the future. The Company applied the simplified method of estimating the expected term of the options, described in the SEC’s Staff Accounting Bulletins 107 and 110. The expected term, calculated under the simplified method, is applied to groups of stock options that have similar contractual terms. Using this method, the expected term is determined using the average of the vesting period and the contractual life of the stock options granted. Dividend rate. The dividend rate is based on the historical rate, which the Company anticipates will remain at zero . The fair market value of the stock options at the date of grant was estimated using the Black-Scholes option-pricing model with the following weighted average assumptions for the years ended December 31: 2018 2017 Expected life (1) 6 years 5 years, 11 months Interest rate 2.6 % 1.9 % Dividend yield — — Volatility 88.0 % 88.7 % (1) The Company uses the simplified method for estimating the stock option term. Stock Option Activity The following table summarizes stock option activity for the years ended December 31, 2018 and 2017: ($ in thousands, except share and per share data) Number of shares Weighted- average exercise price Weighted- average remaining contractual term (in years) Aggregate intrinsic value Outstanding at December 31, 2016 255,906 $ 75.84 7 years, 2 months $ — Granted 59,000 14.41 Expired (42,360 ) 106.73 Forfeited (54,620 ) 47.51 Outstanding at December 31, 2017 217,926 $ 60.31 7 years, 3 months $ — Granted 84,800 2.99 Expired (3,825 ) 34.07 Forfeited (12,189 ) 6.26 Outstanding at December 31, 2018 (1) 286,712 $ 46.01 7 years $ — Exercisable at December 31, 2018 166,871 $ 73.25 5 years, 9 months $ — (1) Includes both vested stock options as well as unvested stock options for which the requisite Company service period has not been rendered but that are expected to vest based on achievement of reaching the Company service period requirement. The total fair value of options vested during the years ended December 31, 2018 and 2017 was approximately $0.5 million for each year, based upon the fair value of the options at grant date. Additionally, as of December 31, 2018, there was approximately $0.5 million of unrecognized compensation expense related to non-vested stock options which is expected to be recognized over a weighted-average period of 1.6 years . During the years ended December 31, 2018 and December 31, 2017, there were no exercises of vested stock options.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Fibrocell Science, Inc. and Fibrocell Technologies, Inc. file a consolidated U.S. federal income tax return, and file U.S. state income tax returns in several jurisdictions as well. In general, the U.S. federal and state income tax returns remain open to examination by taxing authorities for tax years beginning in 2015 to present. However, if and when the Company claims net operating loss (NOL) carryforwards from years prior to 2015 against future taxable income, those losses may be examined by the taxing authorities. The Company’s foreign subsidiaries file income tax returns in their respective jurisdictions. The components of the income tax expense (benefit) related to operations, were as follows: Year ended December 31, ($ in thousands) 2018 2017 U.S. Federal: Current $ — $ — Deferred — — U.S. State: Current — — Deferred — — Income tax expense (benefit) $ — $ — The reconciliation between income tax expense (benefit) at the U.S. federal statutory rate and the amount recorded in the accompanying Consolidated Financial Statements were as follows: Year ended December 31, ($ in thousands) 2018 2017 Tax benefit at U.S. federal statutory rate $ (2,158 ) $ (5,684 ) Increase in domestic valuation allowance 4,815 5,914 State income taxes benefit before valuation allowance, net of federal benefit (897 ) 6 State rate change (2,514 ) 555 State law change 1,418 — Warrant revaluation income and other financing costs (366 ) (898 ) Credits (478 ) (904 ) Stock-based compensation 49 61 Return to provision true-ups 75 127 Capital loss carryforward expiration — 817 Impact of federal rate change — 34,463 Impact of federal rate change on valuation allowance — (34,463 ) Other 56 6 Income tax expense (benefit) $ — $ — The components of the Company’s net deferred tax assets and liabilities at December 31, 2018 and 2017 were as follows: Year ended December 31, ($ in thousands) 2018 2017 Deferred tax liabilities: Convertible notes $ 2,842 $ 2,821 Total deferred tax liabilities $ 2,842 $ 2,821 Deferred tax assets: Loss carryforwards (federal and state) $ 64,285 $ 60,428 Intangible assets 57 68 Property and equipment 839 606 License fees 4,645 4,419 Accrued expenses and other 354 401 Stock-based compensation 2,838 2,753 Research and development tax credits 1,945 1,436 Total deferred tax assets before valuation allowance 74,963 70,111 Less: valuation allowance (72,121 ) (67,290 ) Total deferred tax assets $ 2,842 $ 2,821 Net deferred tax assets $ — $ — As of December 31, 2018, the Company had generated U.S. NOL carryforwards of approximately $251 million of which $237.5 million will expire from 2019 to 2037 and $13.5 million can be carried forward indefinitely. As of December 31, 2018, the Company had generated federal R&D credits of $1.9 million which expire from 2033 to 2038. The NOL carryforwards are available to reduce future taxable income. However, the NOL carryforwards may be, or become subject to, an annual limitation in the event of certain cumulative changes in the ownership interest of significant stockholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, as well as similar state tax provisions. This could limit the amount of NOL’s that the Company can utilize annually to offset future taxable income or tax liabilities. The amount of the annual limitation, if any, will be determined based on the value of the Company immediately prior to an ownership change. Subsequent ownership changes may further affect the limitation in future years. If and when the Company utilizes the NOL carryforwards in a future period, it will perform an analysis to determine the effect, if any, of these loss limitation rules on the NOL carryforward balances. Additionally, U.S. tax laws limit the time during which these carryforwards may be applied against future taxes, therefore, the Company may not be able to take full advantage of these carryforwards for federal income tax purposes. In addition, the Company has NOL carryforwards in certain non-U.S. jurisdictions of approximately $0.3 million . However, it is not expected that these non-U.S. loss carryforwards will ever be utilized, so they are not included in the components of deferred taxes listed above. Finally, there are no unremitted earnings in foreign jurisdictions, so no provision for taxes thereupon is required. As the Company has had cumulative losses and there is no assurance of future taxable income, valuation allowances have been recorded to fully offset deferred tax assets at December 31, 2018 and 2017. The valuation allowance increased by $4.8 million in 2018 which was due to the current year taxable loss. The valuation allowance decreased by $28.5 million in 2017, which was partly due to a $34.4 million decrease due to the reduction of the federal corporate tax rate and partly due to a $5.9 million increase primarily due to the impact of the net losses incurred in 2017. As of December 22, 2017, the United States enacted tax reform legislation “known as H.R. 1”, commonly referred to as the “Tax Cuts and Jobs Act” (TCJA or the “Act”), resulting in significant modifications to existing law. Among other changes, the TCJA permanently lowers the corporate federal income tax rate to 21% from the existing maximum rate of 35% effective for tax years beginning after December 31, 2017. As a result of the reduction of the corporate federal income tax rate to 21%, U.S. GAAP required companies to revalue their deferred tax assets and deferred tax liabilities as of the date of enactment, with the resulting tax effects accounted for in the reporting period of enactment. As a result of this revaluation, the Company incurred $34.5 million income tax expense in continuing operations with a corresponding reduction in the valuation allowance. Therefore, there was no impact on the Company’s consolidated statements of operations or statements of financial position from the reduction in the federal tax rate. The other provisions of the TCJA did not have a material impact on the consolidated financial statements. In response to the enactment of the TCJA, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), which provided guidance on accounting for the tax effects of the Act. SAB 118 provided a measurement period that should not extend beyond one year from the Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, the Company has finalized the accounting for the TCJA as of December 31, 2018 and the final amount recorded in these financial statements for the effect of the corporate tax rate change did not change from the provisional estimate recorded at December 31, 2017.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Overview of Related Parties The Company and Intrexon Corporation (Intrexon) are parties to two distinct exclusive channel collaboration agreements, as more fully described below. Pursuant to these agreements, the Company engages Intrexon for support services for the research and development of product candidates covered under the respective agreements and reimburses Intrexon for its cost for time and materials for such work. Additionally, the Company’s future commitments pursuant to the agreements include cash royalties and various developmental and commercial milestone payments as more fully described below. For the years ended December 31, 2018 and 2017, the Company incurred expenses of approximately $0.5 million and $5.2 million , respectively, for goods and services received from Intrexon. Of the expenses incurred during the 2018 period, $0.1 million related to direct expenses for work performed by Intrexon and $0.4 million related to pass-through costs for work performed under the 2012 ECC. These December 31, 2018 and December 31, 2017 expenses do not include approximately $0.5 million in costs we estimated to settle a dispute with one of Intrexon’s vendors in 2017, and for which there was a corresponding reduction in 2018. Of the expenses incurred during the 2017 period, $1.3 million related to direct expenses for work performed by Intrexon and $3.9 million related to pass-through costs, both for work performed under the 2012 ECC. As of December 31, 2018 and 2017, the Company had outstanding payables with Intrexon of $0.1 million and $2.3 million , respectively. In connection with the 2015 ECC, in consideration for the license and the other rights that the Company receives under the agreement, the Company paid Intrexon an up-front technology access fee of $10 million in cash in January 2016. In the second quarter of 2017, Intrexon notified the Company that it had received invoices for approximately $1.1 million in charges from a vendor who provided services to Intrexon and which are passed-through to the Company under the 2012 ECC. Additional charges were presented after the second quarter of 2017, and the total of disputed charges at March 31, 2018, was approximately $1.4 million . The Company, Intrexon and Intrexon’s vendor have resolved the dispute with the parties agreeing to settle all obligations for approximately $0.2 million . This is a reduction of approximately $0.5 million from the approximately $0.7 million recorded at December 31, 2017 for this liability and was recorded in the three months ended March 31, 2018. The approximately $0.2 million settlement amount was paid in August 2018. Randal J. Kirk is the chairman of the board and chief executive officer of Intrexon and, together with his affiliates, owns more than 50% of Intrexon’s common stock. Affiliates of Randal J. Kirk (including Intrexon) own approximately 17% of the Company’s common stock. Additionally, two of the Company’s directors, Julian Kirk (who is the son of Randal J. Kirk) and Marcus Smith, are employees of Third Security, LLC, which is an affiliate of Randal J. Kirk. Affiliates of Randal J. Kirk (including Intrexon) participated in the Company’s private placement of convertible debt securities in September 2016, more fully described in Note 6, and were issued an aggregate of $6,762,500 in principal of Notes and accompanying Warrants to purchase an aggregate of 450,835 shares of common stock. Affiliates of Randal J. Kirk (including Intrexon) participated in the Company’s March 2017 Series A Convertible Preferred Stock offering, more fully described in Note 8, and were issued an aggregate of 3,016 shares of convertible preferred stock and accompanying warrants to purchase 259,176 shares of common stock. Additionally, affiliates of Randal J. Kirk (including Intrexon) participated in the Company’s December 2017 public offering, and were issued an aggregate of 545,456 shares of common stock and accompanying warrants to purchase 545,456 shares of common stock. Intrexon Collaboration - 2012 ECC In October 2012, the Company entered into an Exclusive Channel Collaboration Agreement with Intrexon which was amended in June 2013 and January 2014 (as amended, the 2012 ECC) pursuant to which the Company is Intrexon’s exclusive channel collaborator in the research, development and commercialization of products in the following fields (the 2012 Fields): • the enhanced production and purification of autologous fibroblasts, without gene therapy, for all aesthetic and therapeutic indications; • the enhanced production and purification of autologous dermal cells, without gene therapy, for aesthetic and therapeutic treatment of dermal, vocal cord, and periodontal indications; • the development of our gene therapies applied to autologous fibroblasts for all aesthetic and therapeutic indications; • the development of our gene therapies applied to autologous dermal cells for aesthetic and therapeutic treatment of dermal, vocal cord, and periodontal indications; • autologous human fibroblasts with gene therapy to express a therapeutic protein and/or bioactive ribonucleic acid for the treatment of autoimmune and non-infectious inflammatory disorders that manifest in cutaneous tissues, fascia and/or muscle; and • autologous human fibroblasts with gene therapy to express bioactive Tenascin-X locally to correct connective tissue disorders associated with Ehlers-Danlos Syndrome (hypermobility type). Pursuant to the terms of the 2012 ECC, Intrexon has granted the Company a license to use its proprietary technologies and other intellectual property to research, develop and commercialize products in the 2012 Fields within the United States. The Company is responsible for all costs incurred in connection with the research, development and commercialization of products under the 2012 ECC and will own all clinical data, regulatory filings and regulatory approvals relating to such products. The Company engages Intrexon for support services for the research and development of products under the 2012 ECC and reimburses Intrexon for its cost for time and materials for such services. In September 2015, the Company and Intrexon entered into a letter of agreement pursuant to which the parties mutually agreed to terminate their collaboration with respect to the development of potential therapies to treat Ehlers-Danlos Syndrome (hypermobility type) due to technical hurdles. As a result, the Company no longer has any rights or obligations under the 2012 ECC with respect to the development of “autologous human fibroblasts genetically modified to express bioactive Tenascin-X locally to correct connective tissue disorders”. The Company is required to pay Intrexon quarterly cash royalties on all products developed under the 2012 ECC in an amount equal to 7% on aggregate quarterly net sales up to $25 million , plus 14% on aggregate quarterly net sales greater than $25 million . The Company is also required to pay Intrexon half of any sublicensing revenues that it receives from third parties in consideration for sublicenses granted by the Company with respect to products developed under the 2012 ECC, but only to the extent such sublicensing revenues are not included in net sales subject to royalties. Sales from LAVIV (azficel-T), including new indications, or other products that the Company develops and commercializes outside of the 2012 ECC are not subject to royalty payments unless the Company is able to reduce the product’s cost of goods sold through the 2012 ECC, in which case, the Company is required to pay quarterly cash royalties on such products equal to one third of such cost of goods sold savings. No royalties have been paid to date in connection with the 2012 ECC. Intrexon Collaboration - 2015 ECC In December 2015, the Company entered into an additional Exclusive Channel Collaboration Agreement with Intrexon (the 2015 ECC) pursuant to which the Company is Intrexon’s exclusive channel collaborator in the research, development and commercialization of products for the treatment of chronic inflammatory and degenerative diseases of human joints through intra-articular or other local administration of genetically modified fibroblasts (the 2015 Field). Pursuant to the terms of the 2015 ECC, Intrexon has granted the Company a license to use its proprietary technologies and other intellectual property to develop and commercialize collaboration products in the 2015 Field throughout the world. The Company is responsible for all costs incurred in connection with the development and commercialization of collaboration products and will own all clinical data, regulatory filings and regulatory approvals relating to such products. The Company engages Intrexon for support services in connection with the research and development of products under the 2015 ECC and reimburses Intrexon for its cost for time and materials for such services. In consideration for the license and the other rights that the Company receives under the 2015 ECC, the Company paid Intrexon an up-front technology access fee of $10 million in cash in January 2016. For each collaboration product the Company develops under the 2015 ECC, the Company is required to pay Intrexon development milestones of up to $30 million and commercialization milestones of up to $22.5 million , a low double-digit royalty on its net sales of such products and half of any sublicensing revenues received from third parties for such products. No royalties or milestone payments have been paid to date in connection with the 2015 ECC.

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Loss Per Share	Loss Per Share Details in the computation of basic and diluted loss per share were as follows: For the Year Ended December 31, ($ in thousands except share and per share data) 2018 2017 Loss per share — Basic: Net loss $ (10,277 ) $ (16,240 ) Less: Dividend paid in-kind to preferred stockholders (336 ) (264 ) Less: Deemed dividend on preferred stock (513 ) (4,099 ) Net loss attributable to common stockholders - basic $ (11,126 ) $ (20,603 ) Numerator for basic loss per share $ (11,126 ) $ (20,603 ) Denominator for basic loss per share 7,693,191 3,092,543 Basic loss per common share $ (1.45 ) $ (6.66 ) Loss per share — Diluted: Numerator for basic loss per share $ (11,126 ) $ (20,603 ) Adjust: Warrant revaluation income for dilutive warrants — (34 ) Numerator for diluted loss per share $ (11,126 ) $ (20,637 ) Denominator for basic loss per share 7,693,191 3,092,543 Plus: Incremental shares underlying “in the money” warrants outstanding — 1,184 Denominator for diluted loss per share 7,693,191 3,093,727 Diluted loss per common share $ (1.45 ) $ (6.67 ) The following potentially dilutive securities have been excluded from the computations of diluted weighted-average shares outstanding, as their effect would be anti-dilutive: For the Year Ended December 31, 2018 2017 “In the money” stock options 19,233 46,869 “Out of the money” stock options 247,897 171,057 “In the money” warrants — — “Out of the money” warrants 7,392,966 4,969,702 Shares underlying convertible notes 1,056,068 1,056,068 Shares underlying accrued interest on convertible notes 101,937 56,752 Shares underlying convertible preferred stock 736,000 704,000

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases On April 6, 2005, the Company entered into a non-cancellable operating lease (the Lease) for its office, warehouse and laboratory facilities in Exton, Pennsylvania. The lease agreement had an original term of 8 years . On February 17, 2012, the Company entered into an amended and restated lease (the Amended Lease) for an additional term of 10 years through the year 2023. The Lease and the Amended Lease provide for rent payments escalating on a periodic basis. In accordance with ASC 840-20, Operating Leases , the Company accounts for total minimum payments under the lease on a straight-line basis over the life of the lease. The difference between actual rent payments and payments accounted for using the straight-line basis are reflected as deferred rent on the Company’s Consolidated Balance Sheets. The Company has the option to renew the lease for an additional 5 years at fair market value. Rental expense totaled approximately $1.6 million for both the years ended December 31, 2018 and 2017. Collaboration with Related Party (Intrexon) The Company is a party to two separate exclusive channel collaboration agreements with Intrexon, a related party. Pursuant to the agreements, the Company is Intrexon’s exclusive channel collaborator in the research, development and commercialization of products in certain defined fields. The Company is required to pay future royalties, as well as development and commercialization milestones, under these agreements. See Note 12 for additional details. Contractual Obligations The following table summarizes the Company’s minimum contractual obligations as of December 31, 2018: Payments due by period ($ in thousands) Total 2019 2020 2021 2022 2023 2024 and thereafter Operating lease obligations (1) 6,197 1,416 1,471 1,471 1,471 368 — Debt obligations (2) 21,968 — — 21,968 — — — Total (3) $ 28,165 $ 1,416 $ 1,471 $ 23,439 $ 1,471 $ 368 $ — (1) Operating lease obligations are stated based on the Amended Lease agreement for the office, warehouse and laboratory facilities executed in February 2012. (2) Obligations under the Notes issued in connection with the 2016 Private Placement which includes principal and accrued interest through September 7, 2021, based on stated fixed rates, as the Company has elected to accrue interest. The Notes have a maturity date of the earlier of (i) September 7, 2026 and (ii) one-hundred and eighty ( 180 ) days after the date on which the Company’s product candidate, FCX-007, is approved by the FDA for the treatment of RDEB. However, each Note holder has the right to require the Company to repay all or any portion of the unpaid principal and accrued interest from time to time on or after September 7, 2021. See details within Note 6. (3) This table does not include (a) any milestone payments which may become payable to third parties under license agreements as the timing and likelihood of such payments are not known, (b) any royalty payments to third parties as the amounts of such payments, timing and/or the likelihood of such payments are not known, and (c) contracts that are entered into in the ordinary course of business which are not material in the aggregate in any period presented above.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies - (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
General	General The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include the accounts of Fibrocell and its wholly owned subsidiaries. The accompanying Consolidated Financial Statements should be read in conjunction with the Notes to the Consolidated Financial Statements. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s foreign operations are immaterial and it has no unrealized gains or losses from the sale of investments. As a result, it does not have any items that would be classified as other comprehensive income in such a statement.
Reclassifications	Reclassifications On May 24, 2018, the Company implemented the 2018 Reverse Stock Split, as authorized at the annual meeting of stockholders on May 23, 2018. The 2018 Reverse Stock Split became effective on May 24, 2018 at 5:00 pm and the Company’s common stock began trading on Nasdaq on a post-split basis at the open of business on May 25, 2018. As of a result of the 2018 Reverse Stock Split, every five shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2018 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2018 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2018 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on Nasdaq. By letter dated June 11, 2018, The Nasdaq Capital Market Listing Qualification Department, confirmed that the Company’s common stock was in compliance with listing requirements. On March 10, 2017, the Company implemented a one-for-three reverse split of its issued and outstanding shares of common stock (the 2017 Reverse Stock Split and together with the 2018 Reverse Stock Split, the Reverse Stock Splits), as authorized at a special meeting of stockholders on March 1, 2017. The 2017 Reverse Stock Split became effective on March 10, 2017 at 5:00 pm and the Company’s common stock began trading on Nasdaq on a post-split basis at the open of business on March 13, 2017. As a result of the 2017 Reverse Stock Split, every three shares of the Company’s issued and outstanding common stock were combined into one share of its common stock, except to the extent that the 2017 Reverse Stock Split resulted in any of the Company’s stockholders owning a fractional share, which was rounded up to the next highest whole share. In connection with the 2017 Reverse Stock Split, there was no change in the nominal par value per share of $0.001 . The 2017 Reverse Stock Split was effectuated in order to increase the per share trading price of the Company’s common stock to satisfy the $1.00 minimum bid price requirement for continued listing on Nasdaq. By letter dated March 27, 2017, The Nasdaq Capital Market Listing Qualification Department, confirmed that the Company’s common stock was in compliance with listing requirements. All share and per share amounts of common stock, options and warrants in the accompanying financial statements have been restated for all periods to give retroactive effect to the Reverse Stock Splits. Accordingly, the Consolidated Statement of Stockholders’ Equity reflects the impact of the Reverse Stock Splits by reclassifying from “Common Stock” to “Additional paid-in capital” an amount equal to the par value of the decreased shares resulting from the Reverse Stock Splits.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosure of contingencies in the accompanying Consolidated Financial Statements and Notes. In addition, management’s assessment of the Company’s ability to continue as a going concern involves the estimation of the amount and timing of future cash inflows and outflows. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable. Actual results may differ materially from those estimates.
Segment Information	Segment Information The Company has determined that it operates in only one segment, as it only reports operational results on an aggregate basis to its chief operating decision maker, the Company’s President and Chief Executive Officer. Additionally, all of the Company’s research and development activities occur in, and assets are located in, the United States.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are limited to the Company’s cash and cash equivalents. As of December 31, 2018, the Company maintains its operating cash with one major U.S. domestic bank and the remainder of its cash and cash equivalents as a money market fund with one major global bank. Federal insurance coverage on operating cash amounted to $250,000 per depositor at each financial institution, and the Company’s non-interest bearing cash balances may exceed federally insured limits. The terms of these deposits are on demand to minimize risk. The Company has not incurred losses related to these deposits.
Property and Equipment	Property and Equipment Property and equipment is carried at acquisition cost less accumulated depreciation, subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable as described further under the heading “Impairment of Long-lived Assets” below. The cost of normal, recurring, or periodic repairs and maintenance activities related to property and equipment are expensed as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if the repair will result in future economic benefits. Depreciation is computed on a straight-line basis over the estimated useful life of the respective assets, which are summarized as follows: Property and equipment category Useful life Computer equipment and software 3 years Laboratory equipment 6 years Furniture and fixtures 10 years Leasehold improvements Lesser of remaining lease term or life of asset When an asset is disposed of, the associated cost and accumulated depreciation is removed from the related accounts on the Company’s Consolidated Balance Sheet with any resulting gain or loss included in the Company’s Consolidated Statement of Operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets In accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 360-10-35, Impairment or Disposal of Long-Lived Assets , the Company reviews its long-lived assets and identifiable finite-lived intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable (i.e. impaired). Once an impairment is determined, the actual impairment recognized would be the difference between the carrying amount and the fair value (less any costs for disposal). The Company uses the following approaches to determine fair value: income, cost and/or market. Fair value using the income approach is determined primarily using a discounted cash flow model that uses the estimated cash flows associated with the asset or asset group under review, discounted at a rate commensurate with the risk involved. Fair value utilizing the cost approach is determined based on the replacement cost of the asset reduced for, among other things, depreciation and obsolescence. Fair value, utilizing the market approach, benchmarks the fair value against the carrying amount.
Warrant Liability	Warrant Liability The Company accounts for stock warrants as either equity instruments, derivative liabilities, or liabilities in accordance with ASC 480, Distinguishing Liabilities from Equity (ASC 480), depending on the specific terms of the warrant agreement. Stock warrants are accounted for as a derivative in accordance with ASC 815, Derivatives and Hedging (ASC 815) if the stock warrants contain terms that could potentially require “net cash settlement” and therefore, do not meet the scope exception for treatment as a derivative. Warrant instruments that could potentially require “net cash settlement” in the absence of express language precluding such settlement are initially classified as derivative liabilities at their estimated fair values, regardless of the likelihood that such instruments will ever be settled in cash. The Company will continue to classify the fair value of the warrants that contain “net cash settlement” as a liability until the warrants are exercised, expire or are amended in a way that would no longer require these warrants to be classified as a liability. Warrants that the Company may be required to redeem through payment of cash or other assets outside its control are classified as liabilities pursuant to ASC 480 and are initially and subsequently measured at their estimated fair values. For additional discussion on warrants, see Note 7.
Debt Issued With Warrants	Debt Issued With Warrants The Company considers guidance within ASC 470-20, Debt (ASC 470), ASC 480, and ASC 815 when accounting for the issuance of convertible debt with detachable warrants. As described above under the caption “ Warrant Liability ”, the Company classifies stock warrants as either equity instruments, derivative liabilities, or liabilities depending on the specific terms of the warrant agreement. In circumstances in which debt is issued with liability-classified warrants, the proceeds from the issuance of convertible debt are first allocated to the warrants at their full estimated fair value and established as both a liability and a debt discount. The remaining proceeds, as further reduced by discounts created by the bifurcation of embedded derivatives and beneficial conversion features, are allocated to the debt. The Company accounts for debt as liabilities measured at amortized cost and amortizes the resulting debt discount from the allocation of proceeds, to interest expense using the effective interest method over the expected term of the debt instrument pursuant to ASC 835, Interest (ASC 835). Embedded Derivatives. The Company considers whether there are any embedded features in debt instruments that require bifurcation and separate accounting as derivative financial instruments pursuant to ASC 815. Embedded derivatives are initially and subsequently measured at fair value. See Note 6 for additional discussion on the embedded derivatives associated with the Company’s convertible notes. Beneficial Conversion Feature. If the amount allocated to the convertible debt results in an effective per share conversion price less than the fair value of the Company’s common stock on the commitment date, the intrinsic value of this beneficial conversion feature is recorded as a discount to the convertible debt with a corresponding increase to additional paid in capital. The beneficial conversion feature discount is equal to the difference between the effective conversion price and the fair value of the Company’s common stock at the commitment date, unless limited by the remaining proceeds allocated to the debt. See Note 6 for additional discussion on the beneficial conversion feature associated with the Company’s convertible notes. Debt Issuance Costs. The Company follows the guidance under Accounting Standards Update (ASU) 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs (ASU 2015-03) for accounting for debt issuance costs. The Company allocates debt issuance costs between the debt and the warrants on the same basis as proceeds were allocated. The Company expenses issuance costs allocated to the warrants and presents the issuance costs allocated to the debt as a direct reduction from the carrying amount of the debt liability in the balance sheet. However, if debt issuance costs exceed the carrying amount of the debt, issuance costs are recorded to additional paid-in capital as a reduction of the beneficial conversion feature. As of December 31, 2018, the Company’s debt issuance costs are presented in additional paid-in capital as a reduction of the beneficial conversion feature and are being amortized to interest expense (despite their classification in additional paid-in capital) using the effective interest rate method over the expected term of the debt pursuant to ASC 835.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred and include employee salaries and benefits, costs incurred with third party contractors to perform research, conduct clinical trials, develop and manufacture drug materials and delivery devices, and a portion of facilities costs. Research and development expenses also include costs to manufacture product for clinical trial use and to develop manufacturing, cell collection and logistical process improvements. Clinical trial costs are a significant component of research and development expenses, often with third party service providers. Invoicing from third party contractors for services performed can lag several months. The Company accrues the costs of services rendered in connection with third party contractor activities based on its estimate of management fees, site management and monitoring costs and data management costs incurred in a given period.
Stock-Based Compensation	Stock-Based Compensation The Company follows ASC 718, Compensation – Stock Compensation (ASC 718), or ASC 505-50, Equity – Equity Based Payments to Non-Employees, where applicable. The Company accounts for stock-based awards to employees using the fair value based method to determine compensation for all arrangements where shares of stock or equity instruments are issued for compensation. In addition, the Company accounts for stock-based compensation to non-employees in accordance with the accounting guidance for equity instruments that are issued to entities or persons other than employees. The Company uses a Black-Scholes option-pricing model to determine the fair value of each option grant as of the date of grant for expense incurred. The Black-Scholes option pricing model requires inputs for risk-free interest rate, dividend yield, expected stock price volatility and expected term of the options. The value of the award vests based on the achievement of the requisite service period. The expense is recognized on a straight line basis. See Note 10 for additional details. The Company considered the guidance in ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09) , which allows an entity to elect as an accounting policy either to continue to estimate the total number of awards for which the requisite service period will not be rendered or to account for forfeitures when they occur. In connection with the adoption of this ASU, the Company made an accounting policy election to account for forfeitures as they occur
Income Taxes	Income Taxes An asset and liability approach is used for financial accounting and reporting for income taxes. Deferred income taxes arise from temporary differences between income tax and financial reporting and principally relate to recognition of revenue and expenses in different periods for financial and tax accounting purposes and are measured using currently enacted tax rates and laws. In addition, a deferred tax asset can be generated by a net operating loss carryover. If it is more likely than not that some portion or all of a deferred tax asset will not be realized, a valuation allowance is recognized. In the event the Company is charged interest or penalties related to income tax matters, the Company would record such interest as interest expense and would record such penalties as other expense in the Consolidated Statements of Operations. No such charges have been incurred by the Company. For each of the years ended December 31, 2018 and 2017, the Company had no uncertain tax positions.
Loss Per Share Data	Loss Per Share Data Basic loss per share is computed by dividing net loss for the period by the weighted average number of shares of common stock outstanding during that period. The diluted loss per share calculation gives effect to dilutive stock options, warrants, convertible notes and other potentially dilutive common stock equivalents outstanding during the period. Diluted loss per share is based on the if-converted method or the treasury stock method, as applicable, and includes the effect from the potential issuance of common stock, such as shares issuable pursuant to the conversion of convertible notes and the exercise of stock options and warrants, assuming the exercise of all “in-the-money” common stock equivalents based on the average market price during the period. Common stock equivalents have been excluded where their inclusion would be anti-dilutive.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) and rules are issued by the Securities and Exchange Commission (SEC) that we adopt as of the specified date. Unless otherwise noted, management does not believe that any other recently issued accounting pronouncements issued by the FASB or guidance issued by the SEC had, or is expected to have, a material impact on the Company’s present or future consolidated financial statements. In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718).” ASU 2018-07 simplifies the accounting for nonemployee share-based payment transactions. This ASU is effective for public entities for interim and annual reporting periods beginning after December 15, 2018. The Company has evaluated the potential impact of this guidance and does not believe that it will have a material impact on the Company’s financial statements. In July 2017, the FASB issued ASU No. 2017-11, “Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480) and Derivatives and Hedging (Topic 815): Part 1 - Accounting for Certain Financial Instruments with Down Round Features and Part 2 - Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with Scope Exception.” Part 1 of ASU No. 2017-11 addresses the complexity of accounting for certain financial instruments with down round features. Down round features are features of certain equity-linked instruments (or embedded features) that result in the strike price being reduced on the basis of the pricing of future equity offerings. Current accounting guidance creates cost and complexity for entities that issue financial instruments (such as warrants and convertible instruments) with down round features that require fair value measurement of the entire instrument or conversion option. Part II of ASU No. 2017-11 addresses the difficulty of navigating Topic 480, Distinguishing Liabilities from Equity, because of the existence of extensive pending content in the FASB Accounting Standards Codification®. This pending content is the result of the indefinite deferral of accounting requirements about mandatorily redeemable financial instruments of certain nonpublic entities and certain mandatorily redeemable noncontrolling interests. For public business entities, the amendments in Part I of this update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The amendments in Part II of this update do not require any transition guidance because those amendments do not have an accounting effect. The Company currently does not have any outstanding financial instruments with down round provisions, and therefore the impact of the adoption of this standard on its Consolidated Financial Statements, will not be material. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under the new guidance, lessees (including lessees under both leases classified as finance leases, which are to be classified based on criteria similar to that applicable to capital leases under current guidance, and leases classified as operating leases) will recognize a right-to-use asset and a lease liability on the balance sheet, initially measured as the present value of lease payments under the lease. Under current guidance, operating leases are not recognized on the balance sheet. The standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition approach for leases with an option to elect a package of practical expedients. Further, companies can elect to apply the transition approach either for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements or those existing at, or entered into after, the adoption date. The Company adopted the new standard effective January 1, 2019 and will not restate comparative periods. Presentation of leases within the consolidated statements of operations and consolidated statements of cash flows will be generally consistent with the current lease accounting guidance. The Company will elect the package of practical expedients permitted under the transition guidance and as such, the adoption of Topic 842 will not change the classification of any of its leases. The Company will elect to combine lease and non-lease components, elect not to record leases with an initial term of 12 months or less on the balance sheet and will recognize the associated lease payments in the consolidated statements of operations on a straight-line basis over the lease term. While the Company is currently assessing the full impact this ASU will have on its Consolidated Financial Statements, management believes the primary impact upon adoption will be the recognition, on a discounted basis, of its minimum commitments under the current non-cancellable operating lease, as amended, for its Exton, PA facility. The impact may result in the recording of right of use assets and lease obligations. The Company does not anticipate any other material impacts to its Consolidated Financial Statements.
Fair Value Measurement	Assumptions Used in Determining Fair Value of Compound Bifurcated Derivative The Company utilizes a binomial lattice model to value its bifurcated derivatives included in the Notes. ASC 815 does not permit an issuer to account separately for individual derivative terms and features embedded in hybrid financial instruments that require bifurcation and liability classification as derivative financial instruments. Rather, such terms and features must be combined together and fair valued as a single, compound embedded derivative. The Company selected a binomial lattice model to value the compound embedded derivative because it believes this technique is reflective of all significant assumptions that market participants would likely consider in negotiating the transfer of the Notes. Such assumptions include, among other inputs: Volatility. The Company estimates stock price volatility based on the Company’s historical stock price performance over a period of time that matches the volume-weighted average expected remaining life of the Notes. Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury zero-coupon yield curve in effect at the valuation date commensurate with the expected remaining life assumption. Expected remaining life. The expected life of the Notes is assumed to be equivalent to their remaining contractual term. Dividend rate. The dividend rate is based on the historical rate, which the Company anticipates will remain at zero . Scenarios. The probability of complex features of the compound bifurcated derivative being triggered is subjective (no observable inputs or available market data) and based on internal and external information known to management at the valuation date. Such assumptions include, among other inputs, probabilities related to a change of control and when it might occur as well as probabilities related to a default under the provisions of the Notes and when it might occur.
Fair Value of Financial Instruments	Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company follows the guidance in ASC 820, Fair Value Measurement , to account for financial assets and liabilities measured on a recurring basis. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company uses a fair value hierarchy, which distinguishes between assumptions based on market data (observable inputs) and an entity’s own assumptions (unobservable inputs). The guidance requires fair value measurements be classified and disclosed in one of the following three categories: • Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; • Level 2: Quoted prices in markets that are not active or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability; • Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Determining which category an asset or liability falls within the hierarchy requires significant judgment. The Company evaluates its hierarchy disclosures each reporting period.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Property and Equipment Useful Lives	Depreciation is computed on a straight-line basis over the estimated useful life of the respective assets, which are summarized as follows: Property and equipment category Useful life Computer equipment and software 3 years Laboratory equipment 6 years Furniture and fixtures 10 years Leasehold improvements Lesser of remaining lease term or life of asset Property and equipment consisted of the following as of: December 31, ($ in thousands) 2018 2017 Laboratory equipment $ 1,562 $ 1,514 Computer equipment and software 319 318 Furniture and fixtures 44 44 Leasehold improvements 1,449 1,412 Construction-in-process 159 101 Total property and equipment, gross 3,533 3,389 Less: Accumulated depreciation (2,311 ) (1,919 ) Total property and equipment, net $ 1,222 $ 1,470

Property and Equipment - (Table

Property and Equipment - (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Depreciation is computed on a straight-line basis over the estimated useful life of the respective assets, which are summarized as follows: Property and equipment category Useful life Computer equipment and software 3 years Laboratory equipment 6 years Furniture and fixtures 10 years Leasehold improvements Lesser of remaining lease term or life of asset Property and equipment consisted of the following as of: December 31, ($ in thousands) 2018 2017 Laboratory equipment $ 1,562 $ 1,514 Computer equipment and software 319 318 Furniture and fixtures 44 44 Leasehold improvements 1,449 1,412 Construction-in-process 159 101 Total property and equipment, gross 3,533 3,389 Less: Accumulated depreciation (2,311 ) (1,919 ) Total property and equipment, net $ 1,222 $ 1,470

Accrued Expenses - (Tables)

Accrued Expenses - (Tables)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Expenses	Accrued expenses consisted of the following as of: December 31, ($ in thousands) 2018 2017 Accrued professional fees $ 281 $ 322 Accrued compensation 449 462 Accrued clinical trial expenses 525 342 Accrued other 215 134 Total accrued expenses $ 1,470 $ 1,260

Convertible Notes - (Tables)

Convertible Notes - (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Convertible Promissory Notes Outstanding	Convertible promissory notes outstanding were as follows: ($ in thousands) December 31, 2018 2017 Convertible promissory notes $ 18,003 $ 18,003 Debt discount - warrants (9,598 ) (9,598 ) Debt discount - compound bifurcated derivatives (1,267 ) (1,267 ) Debt discount - beneficial conversion feature (7,138 ) (7,138 ) Convertible promissory notes, net $ — $ —
Estimated Fair Value of Compounded Bifurcated Derivative	Significant inputs and assumptions used in the binomial lattice model for the derivative liability are as follows: ($ in thousands except per share data) December 31, 2018 December 31, 2017 Calculated aggregate value $ 1,474 $ 3,136 Closing price per share of common stock $ 1.50 $ 3.20 Contractual remaining term 7 years, 8 months 8 years, 8 months Contractual interest rate 4.0 % 4.0 % Volume-weighted average conversion rate $ 17.04667 $ 17.04667 Risk-free interest rate (term structure) 2.44% - 2.69% 1.28% - 2.40% Dividend yield — — Credit Rating CC CC Credit Spread 31.77 % 36.98 % Volatility 87.5 % 99.0 %

Warrants - (Tables)

Warrants - (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Outstanding Liability Classified Warrants to Purchase Common Stock	The following table summarizes the Company’s outstanding warrants to purchase common stock as of: Number of Warrants December 31, 2018 December 31, 2017 Exercise Price Expiration Dates Liability-classified Warrants Issued with June 2012 Convertible Notes — 75,040 $ 37.50 Jun 2018 Issued in Series E Preferred Stock offering — 104,676 $ 112.50 Dec 2018 Issued with September 2016 Convertible Notes 1,205,840 1,205,840 $ 22.50 Sept 2021 1,205,840 1,385,556 Equity-classified Warrants Issued in 2017 Series A Preferred Stock Offering 687,468 687,468 $ 12.69 Mar 2022 Issued in 2017 Common Stock Offering - common warrants 2,679,702 2,809,404 $ 3.85 Dec 2022 Issued in 2017 Common Stock Offering - underwriter warrants 87,274 87,274 $ 4.8125 Dec 2022 Issued in 2017 Common Stock Offering - pre-funded warrants — 483,221 $ 0.05 No expiration Issued in May 2018 Private Placement - common warrants 1,528,668 — $ 2.86 Nov 2023 Issued in May 2018 Registered Direct Offering - underwriter warrants 142,676 — $ 3.679 May 2023 Issued in July 2018 Private Placement - common warrants 958,152 — $ 2.70 Jan 2024 Issued in July 2018 Registered Direct Offering - underwriter warrants 103,186 — $ 3.464 Jul 2023 6,187,126 4,067,367 Total outstanding warrants 7,392,966 5,452,923
Summary of Warrant Activity	The table below is a summary of the Company’s warrant activity for the year ended December 31, 2018. Number of warrants Liability-classified Equity-classified Total Weighted-average exercise price Outstanding at December 31, 2017 1,385,556 4,067,367 5,452,923 $ 11.32 Granted — 2,732,682 2,732,682 2.87 Exercised — (612,923 ) (612,923 ) 0.85 Expired (179,716 ) — (179,716 ) 81.18 Outstanding at December 31, 2018 1,205,840 6,187,126 7,392,966 $ 7.36
Calculated Aggregate Fair Values and Net Cash Settlement Value	The following table summarizes the calculated aggregate fair values, along with the assumptions utilized in each calculation: ($ in thousands, except per share data) December 31, December 31, Calculated aggregate value $ 152 $ 1,073 Weighted average exercise price per share $ 22.50 $ 30.10 Closing price per share of common stock $ 1.50 $ 3.20 Volatility 94.1 % 92.2 % Weighted average remaining expected life 2 years, 8 months 3 years, 4 months Risk-free interest rate 2.45 % 2.00 % Dividend yield — —

Fair Value Measurements - (Tabl

Fair Value Measurements - (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Company's Financial Assets and Liability Measured at Fair Value on a Recurring Basis	The following fair value hierarchy table presents information about each major category of the Company’s financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2017: December 31, 2018 ($ in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 12,290 $ — $ — $ 12,290 Total Assets $ 12,290 $ — $ — $ 12,290 Liabilities: Warrant liability $ — $ — $ 152 $ 152 Derivative liability — — 1,474 1,474 Total Liabilities $ — $ — $ 1,626 $ 1,626 December 31, 2017 ($ in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 14,670 $ — $ — $ 14,670 Total Assets $ 14,670 $ — $ — $ 14,670 Liabilities: Warrant liability $ — $ — $ 1,073 $ 1,073 Derivative liability — — 3,136 3,136 Total Liabilities $ — $ — $ 4,209 $ 4,209
Reconciliation of Warrant Liability Measured at Fair Value on Recurring Basis	The reconciliation of the Company’s warrant liability measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows: ($ in thousands) Warrant Liability Balance at December 31, 2016 $ 6,034 Exercise of warrants (1) (41 ) Change in fair value of warrant liability (2) (4,920 ) Balance at December 31, 2017 $ 1,073 Change in fair value of warrant liability (2) (921 ) Balance at December 31, 2018 $ 152 (1) Warrants were exercised under the cashless exercise method pursuant to the corresponding warrant agreements. As a result of such exercises, the Company issued 6,941 shares of common stock. Consequently, these instruments were no longer classified as liabilities. These common stock warrants were remeasured to their fair value as of the exercise date with the change in fair value recorded to the Company’s Consolidated Statement of Operations. The fair value related to the shares issued in connection with the exercised warrants was reclassified from a liability to additional paid-in capital in the Company’s Consolidated Balance Sheets. (2) Includes the fair value as of the beginning of the year for warrants expiring during the year and has been recorded to warrant revaluation income in the Company’s Consolidated Statement of Operations for the respective year end. The reconciliation of the derivative liability measured at fair value on a recurring basis using unobservable inputs (Level 3) was as follows: ($ in thousands) Derivative Liability Balance at December 31, 2016 $ 1,735 Derivative liability to equity upon note conversion (1) (6 ) Change in fair value of derivative liability 1,407 Balance at December 31, 2017 $ 3,136 Change in fair value of derivative liability (1,662 ) Balance at December 31, 2018 $ 1,474 (1) Convertible notes from the September 2016 Private Placement, were converted to shares of common stock pursuant to the corresponding convertible note agreements. As a result of such conversions, the Company issued 24,911 shares of common stock. Consequently, these instruments were no longer classified as liabilities. These embedded derivatives were remeasured to their fair value as of the exercise date with the change in fair value recorded to the Company’s Consolidated Statement of Operations. The fair value related to the shares issued in connection with the converted notes was reclassified from a liability to additional paid-in capital in the Company’s Consolidated Balance Sheets.

Stock-Based Compensation - (Tab

Stock-Based Compensation - (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Details of Fair Value Option Award	The fair market value of the stock options at the date of grant was estimated using the Black-Scholes option-pricing model with the following weighted average assumptions for the years ended December 31: 2018 2017 Expected life (1) 6 years 5 years, 11 months Interest rate 2.6 % 1.9 % Dividend yield — — Volatility 88.0 % 88.7 % (1) The Company uses the simplified method for estimating the stock option term.
Summary of Stock Option Activity	The following table summarizes stock option activity for the years ended December 31, 2018 and 2017: ($ in thousands, except share and per share data) Number of shares Weighted- average exercise price Weighted- average remaining contractual term (in years) Aggregate intrinsic value Outstanding at December 31, 2016 255,906 $ 75.84 7 years, 2 months $ — Granted 59,000 14.41 Expired (42,360 ) 106.73 Forfeited (54,620 ) 47.51 Outstanding at December 31, 2017 217,926 $ 60.31 7 years, 3 months $ — Granted 84,800 2.99 Expired (3,825 ) 34.07 Forfeited (12,189 ) 6.26 Outstanding at December 31, 2018 (1) 286,712 $ 46.01 7 years $ — Exercisable at December 31, 2018 166,871 $ 73.25 5 years, 9 months $ — (1) Includes both vested stock options as well as unvested stock options for which the requisite Company service period has not been rendered but that are expected to vest based on achievement of reaching the Company service period requirement.

Income Taxes - (Tables)

Income Taxes - (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense Benefit	The components of the income tax expense (benefit) related to operations, were as follows: Year ended December 31, ($ in thousands) 2018 2017 U.S. Federal: Current $ — $ — Deferred — — U.S. State: Current — — Deferred — — Income tax expense (benefit) $ — $ —
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation between income tax expense (benefit) at the U.S. federal statutory rate and the amount recorded in the accompanying Consolidated Financial Statements were as follows: Year ended December 31, ($ in thousands) 2018 2017 Tax benefit at U.S. federal statutory rate $ (2,158 ) $ (5,684 ) Increase in domestic valuation allowance 4,815 5,914 State income taxes benefit before valuation allowance, net of federal benefit (897 ) 6 State rate change (2,514 ) 555 State law change 1,418 — Warrant revaluation income and other financing costs (366 ) (898 ) Credits (478 ) (904 ) Stock-based compensation 49 61 Return to provision true-ups 75 127 Capital loss carryforward expiration — 817 Impact of federal rate change — 34,463 Impact of federal rate change on valuation allowance — (34,463 ) Other 56 6 Income tax expense (benefit) $ — $ —
Schedule of Deferred Tax Assets and Liabilities	The components of the Company’s net deferred tax assets and liabilities at December 31, 2018 and 2017 were as follows: Year ended December 31, ($ in thousands) 2018 2017 Deferred tax liabilities: Convertible notes $ 2,842 $ 2,821 Total deferred tax liabilities $ 2,842 $ 2,821 Deferred tax assets: Loss carryforwards (federal and state) $ 64,285 $ 60,428 Intangible assets 57 68 Property and equipment 839 606 License fees 4,645 4,419 Accrued expenses and other 354 401 Stock-based compensation 2,838 2,753 Research and development tax credits 1,945 1,436 Total deferred tax assets before valuation allowance 74,963 70,111 Less: valuation allowance (72,121 ) (67,290 ) Total deferred tax assets $ 2,842 $ 2,821 Net deferred tax assets $ — $ —

Loss Per Share - (Tables)

Loss Per Share - (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per share	Details in the computation of basic and diluted loss per share were as follows: For the Year Ended December 31, ($ in thousands except share and per share data) 2018 2017 Loss per share — Basic: Net loss $ (10,277 ) $ (16,240 ) Less: Dividend paid in-kind to preferred stockholders (336 ) (264 ) Less: Deemed dividend on preferred stock (513 ) (4,099 ) Net loss attributable to common stockholders - basic $ (11,126 ) $ (20,603 ) Numerator for basic loss per share $ (11,126 ) $ (20,603 ) Denominator for basic loss per share 7,693,191 3,092,543 Basic loss per common share $ (1.45 ) $ (6.66 ) Loss per share — Diluted: Numerator for basic loss per share $ (11,126 ) $ (20,603 ) Adjust: Warrant revaluation income for dilutive warrants — (34 ) Numerator for diluted loss per share $ (11,126 ) $ (20,637 ) Denominator for basic loss per share 7,693,191 3,092,543 Plus: Incremental shares underlying “in the money” warrants outstanding — 1,184 Denominator for diluted loss per share 7,693,191 3,093,727 Diluted loss per common share $ (1.45 ) $ (6.67 )
Securities excluded from calculation of weighted-average shares outstanding	The following potentially dilutive securities have been excluded from the computations of diluted weighted-average shares outstanding, as their effect would be anti-dilutive: For the Year Ended December 31, 2018 2017 “In the money” stock options 19,233 46,869 “Out of the money” stock options 247,897 171,057 “In the money” warrants — — “Out of the money” warrants 7,392,966 4,969,702 Shares underlying convertible notes 1,056,068 1,056,068 Shares underlying accrued interest on convertible notes 101,937 56,752 Shares underlying convertible preferred stock 736,000 704,000

Commitments and Contingencies -

Commitments and Contingencies - (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity Schedule	The following table summarizes the Company’s minimum contractual obligations as of December 31, 2018: Payments due by period ($ in thousands) Total 2019 2020 2021 2022 2023 2024 and thereafter Operating lease obligations (1) 6,197 1,416 1,471 1,471 1,471 368 — Debt obligations (2) 21,968 — — 21,968 — — — Total (3) $ 28,165 $ 1,416 $ 1,471 $ 23,439 $ 1,471 $ 368 $ — (1) Operating lease obligations are stated based on the Amended Lease agreement for the office, warehouse and laboratory facilities executed in February 2012. (2) Obligations under the Notes issued in connection with the 2016 Private Placement which includes principal and accrued interest through September 7, 2021, based on stated fixed rates, as the Company has elected to accrue interest. The Notes have a maturity date of the earlier of (i) September 7, 2026 and (ii) one-hundred and eighty ( 180 ) days after the date on which the Company’s product candidate, FCX-007, is approved by the FDA for the treatment of RDEB. However, each Note holder has the right to require the Company to repay all or any portion of the unpaid principal and accrued interest from time to time on or after September 7, 2021. See details within Note 6. (3) This table does not include (a) any milestone payments which may become payable to third parties under license agreements as the timing and likelihood of such payments are not known, (b) any royalty payments to third parties as the amounts of such payments, timing and/or the likelihood of such payments are not known, and (c) contracts that are entered into in the ordinary course of business which are not material in the aggregate in any period presented above.

Business and Organization - (De

Business and Organization - (Details) $ / shares in Units, $ in Thousands	May 24, 2018$ / shares	Mar. 10, 2017$ / shares	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)$ / shares	Jul. 02, 2018$ / shares	Dec. 31, 2016USD ($)
Subsequent Event [Line Items]
Net loss			$ 10,277	$ 16,240
Accumulated deficit			189,080	178,803
Accumulated deficit			(9,557)	(9,007)		$ (7,861)
Net cash used in operating activities			12,717	17,037
Cash and cash equivalents			14,430	$ 17,417		17,515
Working capital			$ 12,400
Reverse stock split (percentage)	0.2	0.3333
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001	$ 0.001	$ 0.001	$ 0.001
Accumulated deficit
Subsequent Event [Line Items]
Net loss			$ 10,277	$ 16,240
Accumulated deficit			$ 189,080	$ 178,803		$ 162,563

Basis of Presentation - (Detail

Basis of Presentation - (Details)	May 24, 2018$ / shares	Mar. 10, 2017$ / shares	Dec. 31, 2018$ / shares	Jul. 02, 2018$ / shares	Dec. 31, 2017$ / shares
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reverse stock split (percentage)	0.2	0.3333
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001	$ 0.001	$ 0.001

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)
Accounting Policies [Abstract]
Number of operating segments | Segment	1
Federal insurance coverage on operating cash	$ 250,000
Uncertain tax positions	$ 0	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Useful Life (Details)	12 Months Ended
	Dec. 31, 2018
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	3 years
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	6 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	10 years

Property and Equipment - (Detai

Property and Equipment - (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Total property and equipment, gross	$ 3,533	$ 3,389
Less: Accumulated depreciation	(2,311)	(1,919)
Total property and equipment, net	1,222	1,470
Laboratory equipment
Total property and equipment, gross	1,562	1,514
Computer equipment and software
Total property and equipment, gross	319	318
Furniture and fixtures
Total property and equipment, gross	44	44
Leasehold improvements
Total property and equipment, gross	1,449	1,412
Construction-in-process
Total property and equipment, gross	$ 159	$ 101

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation	$ 0.4	$ 0.4

Accrued Expenses - (Details)

Accrued Expenses - (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued professional fees	$ 281	$ 322
Accrued compensation	449	462
Accrued clinical trial expenses	525	342
Accrued other	215	134
Total accrued expenses	$ 1,470	$ 1,260

Convertible Notes - Narrative (

Convertible Notes - Narrative (Details)	1 Months Ended	12 Months Ended
	Sep. 30, 2016USD ($)shares	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Debt discount		$ 18,003,000	$ 18,003,000
Amortization period	5 years
Impact of change in probability of change in control event in the next year		300,000
Impact of change in probability of change in control event in year two		100,000
Change in fair value of derivative liability		100,000
Derivative revaluation income (expense)		1,662,000	(1,407,000)
Issued with September 2016 Convertible Notes
Debt Instrument [Line Items]
Debt discount	$ 9,600,000	9,598,000	9,598,000
Compounded Bifurcated Derivatives
Debt Instrument [Line Items]
Debt discount	1,300,000	1,267,000	1,267,000
Beneficial Conversion Feature
Debt Instrument [Line Items]
Debt discount	$ 7,200,000	$ 7,138,000	7,138,000
Issued with September 2016 Convertible Notes
Debt Instrument [Line Items]
Warrants issued to purchase common stock (in shares) | shares	1,205,840
Convertible Debt
Debt Instrument [Line Items]
Convertible debt principal	$ 18,087,500
Interest rate	4.00%
Period after product candidate FCX-007 is approved to reach maturity date	180 days	180 days
Required written notice period prior to exercise of put right	180 days
Prepayment as a percent of outstanding principal	101.00%
Debt discount	$ 18,100,000
Amortization expense		$ 0	$ 100,000
Effective yield	1157.00%
Convertible Debt | Option Two
Debt Instrument [Line Items]
Additional conversion price (usd per share) | $ / shares		$ 0.12625
Convertible Debt | Option Two | Minimum
Debt Instrument [Line Items]
Conversion price (usd per share) | $ / shares		17.04375
Convertible Debt | Option Two | Maximum
Debt Instrument [Line Items]
Conversion price (usd per share) | $ / shares		$ 18.39375
Binomial Lattice Model | Compounded Bifurcated Derivatives | Dividend yield
Debt Instrument [Line Items]
Measurement input		0	0
Binomial Lattice Model | Compounded Bifurcated Derivatives | Credit Spread
Debt Instrument [Line Items]
Measurement input		0.3177	0.3698

Convertible Notes - Promissory

Convertible Notes - Promissory Notes Outstanding (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Debt discount	$ (18,003)	$ (18,003)
Convertible Debt
Debt Instrument [Line Items]
Convertible promissory notes	18,003	18,003
Debt discount			$ (18,100)
Convertible promissory notes, net	0	0
Issued with September 2016 Convertible Notes
Debt Instrument [Line Items]
Debt discount	(9,598)	(9,598)	(9,600)
Compounded Bifurcated Derivatives
Debt Instrument [Line Items]
Debt discount	(1,267)	(1,267)	(1,300)
Beneficial Conversion Feature
Debt Instrument [Line Items]
Debt discount	$ (7,138)	$ (7,138)	$ (7,200)

Convertible Notes - Estimated F

Convertible Notes - Estimated Fair Value (Details) - Compounded Bifurcated Derivatives - Binomial Lattice Model - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Calculated aggregate value	$ 1,474	$ 3,136
Closing price per share of common stock (usd per share)	$ 1.50	$ 3.20
Contractual remaining term	7 years 8 months	8 years 8 months
Contractual interest rate	4.00%	4.00%
Volume-weighted average conversion rate
Debt Instrument [Line Items]
Measurement input	17.04667	17.04667
Risk-free interest rate (term structure) | Minimum
Debt Instrument [Line Items]
Measurement input	0.0244	0.0128
Risk-free interest rate (term structure) | Maximum
Debt Instrument [Line Items]
Measurement input	0.0269	0.0240
Dividend yield
Debt Instrument [Line Items]
Measurement input	0	0
Credit Spread
Debt Instrument [Line Items]
Measurement input	0.3177	0.3698
Volatility
Debt Instrument [Line Items]
Measurement input	0.875	0.990

Warrants - Narrative (Details)

Warrants - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	May 31, 2018	May 29, 2018	Dec. 11, 2017	Dec. 08, 2017	Jul. 31, 2018	May 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Jan. 06, 2018	Dec. 07, 2017
Class of Warrant or Right [Line Items]
Number of warrants (shares)							5,452,923			7,392,966	5,452,923
Warrants exercise price (usd per share)							$ 11.32			$ 7.36	$ 11.32
Warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)							1,385,556			1,205,840	1,385,556
Level 3 | Warrants
Class of Warrant or Right [Line Items]
Non-cash expense (income) resulting from change in estimated fair value										$ 0.9	$ 4.9
Issued in 2017 Common Stock Offering - pre-funded warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)							1,184,422				1,184,422		1,184,422
Issued in 2017 Common Stock Offering - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)				82,118			82,118				82,118	409,091	2,809,404
Issued in 2017 Series A Preferred Stock Offering
Class of Warrant or Right [Line Items]
Number of warrants (shares)								687,468
Warrants exercise price (usd per share)								$ 12.69
Warrant exercise period								5 years
Period of time after issuance for warrants to become exercisable								6 months
Issued with September 2016 Convertible Notes
Class of Warrant or Right [Line Items]
Number of warrants (shares)							1,205,840		1,205,840	1,205,840	1,205,840
Warrants exercise price (usd per share)									$ 22.50	$ 22.50
Warrant exercise period									5 years
Period of time after issuance for warrants to become exercisable									6 months
Warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)							4,067,367			6,187,126	4,067,367
Warrants | Issued in July 2018 Private Placement - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)					958,152		0			958,152	0
Warrants exercise price (usd per share)					$ 2.70					$ 2.70
Warrant exercise period					5 years 6 months
Warrants | Issued in July 2018 Registered Direct Offering - underwriter warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)					103,186		0			103,186	0
Warrants exercise price (usd per share)					$ 3.464					$ 3.464
Warrants | Warrants Issued in 2018 Private Placement - Common Warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	1,528,668					1,528,668
Warrants exercise price (usd per share)	$ 2.86					$ 2.86
Warrant exercise period		5 years 6 months				5 years 6 months
Warrants | Issued in May 2018 Registered Direct Offering - underwriter warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	142,676					142,676	0			142,676	0
Warrants exercise price (usd per share)	$ 3.679					$ 3.679				$ 3.679
Warrant exercise period	5 years
Warrants | Issued in 2017 Common Stock Offering - pre-funded warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)							483,221			0	483,221
Warrants exercise price (usd per share)			$ 0.05							$ 0.05
Warrants | Issued in 2017 Common Stock Offering - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)							2,809,404			2,679,702	2,809,404
Warrants exercise price (usd per share)			$ 3.85				$ 3.85			$ 3.85	$ 3.85	$ 3.85	$ 3.85
Warrant exercise period			5 years				5 years
Warrants | Issued in 2017 Common Stock Offering - underwriter warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)				87,274			87,274			87,274	87,274
Warrants exercise price (usd per share)			$ 4.8125	$ 4.8125			$ 4.8125			$ 4.8125	$ 4.8125
Warrant exercise period			5 years	5 years			5 years
Warrants | Issued in 2017 Series A Preferred Stock Offering
Class of Warrant or Right [Line Items]
Number of warrants (shares)							687,468			687,468	687,468
Warrants exercise price (usd per share)										$ 12.69
Common Stock | Issued in 2017 Common Stock Offering - common warrants
Class of Warrant or Right [Line Items]
Number of shares per warrant (shares)													1
Common Stock | Warrants | Issued in 2017 Common Stock Offering - common warrants
Class of Warrant or Right [Line Items]
Number of shares per warrant (shares)							1				1

Warrants - Outstanding Liabilit

Warrants - Outstanding Liability Classified Warrants to Purchase Common Stock (Details) - $ / shares	Dec. 31, 2018	Jul. 31, 2018	May 31, 2018	Jan. 06, 2018	Dec. 31, 2017	Dec. 11, 2017	Dec. 08, 2017	Dec. 07, 2017	Mar. 31, 2017	Sep. 30, 2016
Class of Warrant or Right [Line Items]
Number of warrants (shares)	7,392,966				5,452,923
Warrants exercise price (usd per share)	$ 7.36				$ 11.32
Issued with June 2012 Convertible Notes
Class of Warrant or Right [Line Items]
Number of warrants (shares)	0				75,040
Warrants exercise price (usd per share)	$ 37.50
Issued in Series E Preferred Stock offering
Class of Warrant or Right [Line Items]
Number of warrants (shares)	0				104,676
Warrants exercise price (usd per share)	$ 112.50
Issued with September 2016 Convertible Notes
Class of Warrant or Right [Line Items]
Number of warrants (shares)	1,205,840				1,205,840					1,205,840
Warrants exercise price (usd per share)	$ 22.50									$ 22.50
Issued in 2017 Series A Preferred Stock Offering
Class of Warrant or Right [Line Items]
Number of warrants (shares)									687,468
Warrants exercise price (usd per share)									$ 12.69
Issued in 2017 Common Stock Offering - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)				409,091	82,118		82,118	2,809,404
Issued in 2017 Common Stock Offering - pre-funded warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)					1,184,422			1,184,422
Warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	6,187,126				4,067,367
Warrants | Issued in 2017 Series A Preferred Stock Offering
Class of Warrant or Right [Line Items]
Number of warrants (shares)	687,468				687,468
Warrants exercise price (usd per share)	$ 12.69
Warrants | Issued in 2017 Common Stock Offering - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	2,679,702				2,809,404
Warrants exercise price (usd per share)	$ 3.85			$ 3.85	$ 3.85	$ 3.85		$ 3.85
Warrants | Issued in 2017 Common Stock Offering - underwriter warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	87,274				87,274		87,274
Warrants exercise price (usd per share)	$ 4.8125				$ 4.8125	4.8125	$ 4.8125
Warrants | Issued in 2017 Common Stock Offering - pre-funded warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	0				483,221
Warrants exercise price (usd per share)	$ 0.05					$ 0.05
Warrants | Issued in May 2018 Private Placement - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	1,528,668				0
Warrants exercise price (usd per share)	$ 2.86
Warrants | Issued in May 2018 Registered Direct Offering - underwriter warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	142,676		142,676		0
Warrants exercise price (usd per share)	$ 3.679		$ 3.679
Warrants | Issued in July 2018 Private Placement - common warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	958,152	958,152			0
Warrants exercise price (usd per share)	$ 2.70	$ 2.70
Warrants | Issued in July 2018 Registered Direct Offering - underwriter warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	103,186	103,186			0
Warrants exercise price (usd per share)	$ 3.464	$ 3.464
Warrants
Class of Warrant or Right [Line Items]
Number of warrants (shares)	1,205,840				1,385,556

Warrants - Summary of Warrant A

Warrants - Summary of Warrant Activity (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Increase (Decrease) in Warrants Outstanding [Roll Forward]
Number of warrants outstanding (shares), beginning balance	5,452,923
Number of warrants granted during the period (shares)	2,732,682
Number of warrants exercised during the period (shares)	(612,923)
Number of warrants expired during the period (share)	(179,716)
Number of warrants outstanding (shares), ending balance	7,392,966
Warrants exercise price (usd per share), beginning balance | $ / shares	$ 11.32
Weighted-average exercise price, warrants granted during the period (usd per share) | $ / shares	2.87
Weighted-average exercise price, warrants exercised during the period (usd per share) | $ / shares	0.85
Weighted-average exercise price, warrants expired during the period (usd per share) | $ / shares	81.18
Warrants exercise price (usd per share), ending balance | $ / shares	$ 7.36
Warrants
Increase (Decrease) in Warrants Outstanding [Roll Forward]
Number of warrants outstanding (shares), beginning balance	1,385,556
Number of warrants granted during the period (shares)	0
Number of warrants exercised during the period (shares)	0
Number of warrants expired during the period (share)	(179,716)
Number of warrants outstanding (shares), ending balance	1,205,840
Warrants
Increase (Decrease) in Warrants Outstanding [Roll Forward]
Number of warrants outstanding (shares), beginning balance	4,067,367
Number of warrants granted during the period (shares)	2,732,682
Number of warrants exercised during the period (shares)	(612,923)
Number of warrants expired during the period (share)	0
Number of warrants outstanding (shares), ending balance	6,187,126

Warrants - Calculated Aggregate

Warrants - Calculated Aggregated Fair Values and Assumptions (Details) - Warrant Liability $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)$ / shares
Class of Warrant or Right [Line Items]
Calculated aggregate value | $	$ 152	$ 1,073
Weighted average exercise price per share of warrant (usd per share)	$ 22.50	$ 30.10
Closing price per share of common stock (usd per share)	$ 1.50	$ 3.20
Volatility
Class of Warrant or Right [Line Items]
Warrant measurement input	0.941	0.922
Measurement Input, Expected Term
Class of Warrant or Right [Line Items]
Weighted average remaining expected life	2 years 8 months	3 years 4 months
Risk-free interest rate (term structure)
Class of Warrant or Right [Line Items]
Warrant measurement input	0.0245	0.0200
Dividend yield
Class of Warrant or Right [Line Items]
Warrant measurement input	0	0

Equity - Preferred Stock (Detai

Equity - Preferred Stock (Details) $ / shares in Units, $ in Thousands	Jan. 06, 2018$ / sharesshares	Mar. 08, 2017USD ($)	Mar. 07, 2017USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Mar. 31, 2017shares
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares				5,000,000	5,000,000
Preferred stock, par value (in dollars per share) | $ / shares				$ 0.001	$ 0.001
Number of units issued (shares) | shares	409,091
Purchase price per unit (in usd per share) | $ / shares	$ 3.80
Preferred shares issued (in shares) | shares				8,000	8,000
Deemed dividend on preferred stock				$ 513	$ 4,099
Dividend paid in-kind to preferred stockholders				336	264
2017 Private Placement
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares			$ 1,000
Preferred shares issued (in shares) | shares			1
Conversion price (usd per share) | $ / shares			$ 11.6355
Number of common shares authorized for purchase as a percent of conversion shares			100.00%
Series A Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares						8,000
Dividend paid in-kind to preferred stockholders				300	300
Series A Convertible Preferred Stock | 2017 Private Placement
Class of Stock [Line Items]
Shares issued upon conversion (in shares) | shares			85
Proceeds for issuance of preferred stock, gross		$ 8,000	$ 1,300
Dividend rate, preferred stock			4.00%
Dividend rate, period of initial rate			5 years
Increased dividend rate, preferred stock			8.00%
Proceeds from beneficial conversion feature			$ 3,700
Deemed dividend on preferred stock				500	4,100
Ownership percentage, convertible preferred stock			70.00%
Units | 2017 Private Placement
Class of Stock [Line Items]
Number of units issued (shares) | shares			8,000
Purchase price per unit (in usd per share) | $ / shares			$ 1,000
Warrants
Class of Stock [Line Items]
Discount on shares, preferred stock			$ 3,000
Deemed dividend on preferred stock				$ 500	$ 300
Risk-free interest rate (term structure) | Series A Convertible Preferred Stock | 2017 Private Placement
Class of Stock [Line Items]
Risk-free interest rate			0.0315
Credit Spread | Series A Convertible Preferred Stock | 2017 Private Placement
Class of Stock [Line Items]
Risk-free interest rate			0.3127
Measurement Input, Market Yield | Series A Convertible Preferred Stock | 2017 Private Placement
Class of Stock [Line Items]
Risk-free interest rate			0.3442

Equity - Common Stock (Details)

Equity - Common Stock (Details) $ / shares in Units, $ in Thousands	Dec. 11, 2018USD ($)shares	Jul. 05, 2018USD ($)$ / sharesshares	Jul. 02, 2018$ / sharesshares	May 31, 2018USD ($)$ / sharesshares	May 29, 2018$ / sharesshares	May 24, 2018$ / shares	Jan. 06, 2018$ / sharesshares	Dec. 11, 2017USD ($)$ / shares	Dec. 08, 2017$ / sharesshares	Dec. 07, 2017$ / sharesshares	Mar. 10, 2017$ / shares	May 31, 2018$ / sharesshares	Dec. 31, 2017$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Jul. 31, 2016shares
Class of Stock [Line Items]
Common stock, shares authorized (in shares)													150,000,000	150,000,000	150,000,000	100,000,000
Reverse stock split (percentage)						0.2					0.3333
Common stock, par value (in dollars per share) | $ / shares			$ 0.001			$ 0.001					$ 0.001		$ 0.001	$ 0.001	$ 0.001
Sale of common stock (shares)							409,091
Number of warrants (shares)													5,452,923	7,392,966	5,452,923
Purchase price (in usd per share) | $ / shares							$ 3.80
Warrants exercise price (usd per share) | $ / shares													$ 11.32	$ 7.36	$ 11.32
Proceeds from common stock offerings, (net of offering costs of $1,170) | $				$ 5,300				$ 9,300						$ 8,915	$ 9,749
Percentage of aggregate shares of common stock available for purchase				7.00%
Issued in 2017 Common Stock Offering - pre-funded warrants
Class of Stock [Line Items]
Number of warrants (shares)										1,184,422			1,184,422		1,184,422
Issued in 2017 Common Stock Offering - common warrants
Class of Stock [Line Items]
Number of warrants (shares)							409,091		82,118	2,809,404			82,118		82,118
Purchase price (in usd per share) | $ / shares							$ 0.05
Warrants
Class of Stock [Line Items]
Number of warrants (shares)													4,067,367	6,187,126	4,067,367
Warrants | Warrants Issued in July 2018 Private Placement
Class of Stock [Line Items]
Number of warrants (shares)			958,152
Purchase price (in usd per share) | $ / shares			$ 0.125
Warrants exercise price (usd per share) | $ / shares		$ 3.464	$ 2.70
Warrant exercise period		5 years	5 years 6 months
Shares of common stock available for purchase		103,186
Warrants | Warrants Issued in 2018 Private Placement - Common Warrants
Class of Stock [Line Items]
Number of warrants (shares)				1,528,668								1,528,668
Purchase price (in usd per share) | $ / shares					$ 0.125
Warrants exercise price (usd per share) | $ / shares				$ 2.86								$ 2.86
Warrant exercise period					5 years 6 months							5 years 6 months
Warrants | Issued in May 2018 Registered Direct Offering - underwriter warrants
Class of Stock [Line Items]
Number of warrants (shares)				142,676								142,676	0	142,676	0
Warrants exercise price (usd per share) | $ / shares				$ 3.679								$ 3.679		$ 3.679
Warrant exercise period				5 years
Warrants | Issued in 2017 Common Stock Offering - pre-funded warrants
Class of Stock [Line Items]
Number of warrants (shares)													483,221	0	483,221
Warrants exercise price (usd per share) | $ / shares								$ 0.05						$ 0.05
Warrants | Issued in 2017 Common Stock Offering - common warrants
Class of Stock [Line Items]
Number of warrants (shares)													2,809,404	2,679,702	2,809,404
Warrants exercise price (usd per share) | $ / shares							$ 3.85	$ 3.85		$ 3.85			$ 3.85	$ 3.85	$ 3.85
Warrant exercise period								5 years					5 years
Warrants | Issued in 2017 Common Stock Offering - underwriter warrants
Class of Stock [Line Items]
Number of warrants (shares)									87,274				87,274	87,274	87,274
Warrants exercise price (usd per share) | $ / shares								$ 4.8125	$ 4.8125				$ 4.8125	$ 4.8125	$ 4.8125
Warrant exercise period								5 years	5 years				5 years
July 2018 Purchase Agreement
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 2.69
Sale of common stock (shares)			1,474,080
Percentage of common stock sold			65.00%
Proceeds from common stock offerings, (net of offering costs of $1,170) | $		$ 3,600
May 2018 Purchase Agreement
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares					$ 0.001
Sale of common stock (shares)					2,038,224
Percentage of common stock sold					75.00%
Purchase price (in usd per share) | $ / shares					$ 2.85
Public Stock Offering
Class of Stock [Line Items]
Sale of common stock (shares)										1,542,832
Common Stock | Issued in 2017 Common Stock Offering - common warrants
Class of Stock [Line Items]
Number of shares per warrant (shares)										1
Common Stock | Warrants | Issued in 2017 Common Stock Offering - common warrants
Class of Stock [Line Items]
Number of shares per warrant (shares)													1		1
Common Stock | December 2018 Private Placement
Class of Stock [Line Items]
Sale of common stock (shares)	443,350
Gross consideration received for sale of stock | $	$ 900
Expected proceeds from offering | $	$ 800

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - Estimate of Fair Value Measurement - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 12,290	$ 14,670
Total Assets	12,290	14,670
Warrant liability	152	1,073
Derivative liability	1,474	3,136
Total Liabilities	1,626	4,209
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	12,290	14,670
Total Assets	12,290	14,670
Warrant liability	0	0
Derivative liability	0	0
Total Liabilities	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Total Assets	0	0
Warrant liability	0	0
Derivative liability	0	0
Total Liabilities	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Total Assets	0	0
Warrant liability	152	1,073
Derivative liability	1,474	3,136
Total Liabilities	$ 1,626	$ 4,209

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Warrant Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Common Stock
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Issuance of shares from cashless warrant exercises (shares)	6,941
Issuance of shares from conversion of convertible notes (in shares)	24,911
Warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 1,073	$ 6,034
Exercise of warrants		(41)
Change in fair value of liability	(921)	(4,920)
Ending Balance	152	1,073
Derivative Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	3,136	1,735
Change in fair value of liability	(1,662)	1,407
Issuance of convertible notes		(6)
Ending Balance	$ 1,474	$ 3,136

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value of convertible promissory notes	$ 12,500,000	$ 11,200,000
Carrying value of convertible promissory notes	$ 0	$ 0

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair market value of options granted (usd per share)	$ 2.22	$ 10.58
Stock-based compensation expense	$ 0.5	$ 0.3
Dividend rate	0.00%	0.00%
Fair value of shares vested	$ 0.5	$ 0.5
Options exercises in period	0	0
Service Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 0.5
Weighted-average period to recognize compensation cost (years)	1 year 7 months
2009 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance	506,667
2009 Equity Incentive Plan | Share Based Compensation Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration term, do not exceed (years)	10 years
Stock options vesting percent per year	25.00%
Stock options vesting term (years)	4 years
Options available for grant (shares)	215,670
2009 Equity Incentive Plan | Share Based Compensation, Non-employee Director Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting term (years)	1 year

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Market Value of Stock Options (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected life	6 years	5 years 11 months
Interest rate	2.60%	1.90%
Dividend yield	0.00%	0.00%
Volatility	88.00%	88.70%

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of shares outstanding, beginning balance	217,926	255,906
Number of shares, granted	84,800	59,000
Number of shares, expired	(3,825)	(42,360)
Number of shares, forfeited	(12,189)	(54,620)
Number of shares outstanding, ending balance	286,712	217,926	255,906
Number of shares, exercisable	166,871
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-average exercise price, outstanding (usd per share), beginning balance	$ 60.31	$ 75.84
Weighted-average exercise price, granted (usd per share)	2.99	14.41
Weighted-average exercise price, expired (usd per share)	34.07	106.73
Weighted-average exercise price, forfeited (usd per share)	6.26	47.51
Weighted-average exercise price, outstanding (usd per share), ending balance	46.01	$ 60.31	$ 75.84
Weighted-average exercise price, exercisable (usd per share)	$ 73.25
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-average remaining contractual term (in years), outstanding	7 years	7 years 3 months	7 years 2 months
Weighted-average remaining contractual term (in years), exercisable	5 years 9 months
Aggregate intrinsic value, outstanding	$ 0	$ 0	$ 0
Aggregate intrinsic value, exercisable	$ 0

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense/(Benefit) Related to Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
U.S. Federal:
Current	$ 0	$ 0
Deferred	0	0
U.S. State:
Current	0	0
Deferred	0	0
Income tax expense (benefit)	$ 0	$ 0

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes/(Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax benefit at U.S. federal statutory rate	$ (2,158)	$ (5,684)
Increase in domestic valuation allowance	4,815	5,914
State income taxes benefit before valuation allowance, net of federal benefit	(897)	6
State law change	1,418	0
Warrant revaluation income and other financing costs	(366)	(898)
Credits	(478)	(904)
Stock-based compensation	49	61
Return to provision true-ups	75	127
Capital loss carryforward expiration	0	817
Impact of federal rate change on valuation allowance	0	(34,463)
Other	56	6
Income tax expense (benefit)	0	0
State and Local Jurisdiction
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Impact of rate change	(2,514)	555
Domestic Tax Authority
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Impact of rate change	$ 0	$ 34,463

Income Taxes - Net Deferred Tax

Income Taxes - Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax liabilities:
Convertible notes	$ 2,842	$ 2,821
Total deferred tax liabilities	2,842	2,821
Deferred tax assets:
Loss carryforwards (federal and state)	64,285	60,428
Intangible assets	57	68
Property and equipment	839	606
License fees	4,645	4,419
Accrued expenses and other	354	401
Stock-based compensation	2,838	2,753
Research and development tax credits	1,945	1,436
Total deferred tax assets before valuation allowance	74,963	70,111
Less: valuation allowance	(72,121)	(67,290)
Total deferred tax assets	2,842	2,821
Net deferred tax assets	$ 0	$ 0

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	$ 4,800	$ (28,500)
Increase in domestic valuation allowance	4,815	5,914
Impact of federal rate change on valuation allowance		34,400
Impact of federal rate change		$ 34,500
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	251,000
Net operating loss carryforwards, subject to expiration	237,500
Net operating loss carryforwards, not subject to expiration	13,500
Domestic Tax Authority | Research and development
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1,900
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 300

Related Party Transactions - (D

Related Party Transactions - (Details)	Jan. 06, 2018shares	Dec. 31, 2017USD ($)shares	Jan. 31, 2016USD ($)	Mar. 31, 2018USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2018USD ($)directoragreementshares	Dec. 31, 2017USD ($)shares	Aug. 31, 2018USD ($)	Mar. 07, 2017shares	Sep. 30, 2016USD ($)shares
Related Party Transaction [Line Items]
Number of collaboration agreements | agreement						2
Research and development expenses						$ 6,018,000	$ 6,512,000
Related party payable		$ 2,303,000				$ 100,000	$ 2,303,000
Preferred shares issued (in shares) | shares		8,000				8,000	8,000
Common stock, shares issued (shares) | shares	409,091
2017 Private Placement
Related Party Transaction [Line Items]
Preferred shares issued (in shares) | shares									1
Issued with September 2016 Convertible Notes
Related Party Transaction [Line Items]
Warrants issued to purchase common stock (in shares) | shares										1,205,840
Convertible Debt
Related Party Transaction [Line Items]
Convertible debt principal										$ 18,087,500
Technology Access Fee
Related Party Transaction [Line Items]
Payments to Intrexon			$ 10,000,000
Development Milestone
Related Party Transaction [Line Items]
Possible required payments to Intrexon						$ 30,000,000
Commercialization Milestone
Related Party Transaction [Line Items]
Possible required payments to Intrexon						22,500,000
Milestones
Related Party Transaction [Line Items]
Payments to Intrexon						0
Affiliated Entity
Related Party Transaction [Line Items]
Research and development expenses - related party						500,000	$ 5,200,000
Trade payables		$ 2,300,000				100,000	2,300,000
Research and development expenses						$ (34,000)	$ 5,720,000
Ownership percent of related party						50.00%
Ownership percent of company common stock						17.00%
Cash royalty, net sales benchmark						$ 25,000,000
Royalty expense, percent of cost of goods sold (percentage)						33.33%
Payments to Intrexon						$ 0
Affiliated Entity | Minimum
Related Party Transaction [Line Items]
Cash royalty, percent of sales						7.00%
Affiliated Entity | Maximum
Related Party Transaction [Line Items]
Cash royalty, percent of sales						14.00%
Affiliated Entity | 2017 Private Placement
Related Party Transaction [Line Items]
Warrants issued to purchase common stock (in shares) | shares		545,456					545,456		259,176
Preferred shares issued (in shares) | shares									3,016
Common stock, shares issued (shares) | shares		545,456
Affiliated Entity | Issued with September 2016 Convertible Notes
Related Party Transaction [Line Items]
Warrants issued to purchase common stock (in shares) | shares										450,835
Affiliated Entity | Convertible Debt
Related Party Transaction [Line Items]
Convertible debt principal										$ 6,762,500
Affiliated Entity | Direct Expenses for Work Performed
Related Party Transaction [Line Items]
Research and development expenses - related party						$ 100,000	$ 1,300,000
Affiliated Entity | Pass-through Costs
Related Party Transaction [Line Items]
Research and development expenses - related party						400,000	3,900,000
Affiliated Entity | Reduction For Settlement Of Disputed Charges
Related Party Transaction [Line Items]
Research and development expenses - related party						$ 500,000	500,000
Affiliated Entity | 2012 Exclusive Channel Collaboration Agreement Dispute
Related Party Transaction [Line Items]
Research and development expenses				$ 1,400,000	$ 1,100,000
Related party payable		$ 700,000			$ 200,000		$ 700,000	$ 200,000
Reduction in due to related parties				$ 500,000
Director
Related Party Transaction [Line Items]
Number of directors | director						2

Loss Per Share - (Details)

Loss Per Share - (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net loss	$ (10,277)	$ (16,240)
Less: Dividend paid in-kind to preferred stockholders	(336)	(264)
Less: Deemed dividend on preferred stock	(513)	(4,099)
Earnings Per Share, Basic [Abstract]
Net loss	$ (11,126)	$ (20,603)
Denominator for basic loss per share (in shares)	7,693,191	3,092,543
Basic loss per common share (in dollars per share)	$ (1.45)	$ (6.66)
Earnings Per Share, Diluted [Abstract]
Numerator for basic loss per share	$ (11,126)	$ (20,603)
Warrant revaluation income (expense) for dilutive warrants	0	(34)
Numerator for diluted loss per share	$ (11,126)	$ (20,637)
Denominator for basic loss per share (in shares)	7,693,191	3,092,543
Incremental shares underlying in the money warrants outstanding (in shares)	0	1,184
Denominator for diluted loss per share (in shares)	7,693,191	3,093,727
Diluted net income (loss) per share (in dollars per share)	$ (1.45)	$ (6.67)

Loss Per Share - Antidilutive S

Loss Per Share - Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
“In the money” stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	19,233	46,869
“Out of the money” stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	247,897	171,057
“In the money” warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	0	0
“Out of the money” warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	7,392,966	4,969,702
Shares underlying convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	1,056,068	1,056,068
Shares underlying accrued interest on convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	101,937	56,752
Shares underlying convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	736,000	704,000

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)agreement	Dec. 31, 2017USD ($)	Feb. 17, 2012	Apr. 06, 2005
Loss Contingencies [Line Items]
Lease agreement term (years)				8 years
Additional lease term (years)	5 years
Rental expense | $	$ 1.6	$ 1.6
Number of collaboration agreements | agreement	2
Amended Lease
Loss Contingencies [Line Items]
Lease agreement term (years)			10 years

Commitments and Contingencies_3

Commitments and Contingencies - (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2018
Other Commitments [Line Items]
Total		$ 28,165
2019		1,416
2020		1,471
2021		23,439
2022		1,471
2023		368
2024 and thereafter		$ 0
Convertible Debt
Other Commitments [Line Items]
Period after product candidate FCX-007 is approved to reach maturity date	180 days	180 days
Operating lease obligations
Other Commitments [Line Items]
Total		$ 6,197
2019		1,416
2020		1,471
2021		1,471
2022		1,471
2023		368
2024 and thereafter		0
Debt obligations
Other Commitments [Line Items]
Total		21,968
2019		0
2020		0
2021		21,968
2022		0
2023		0
2024 and thereafter		$ 0