Zevra Therapeutics (ZVRA) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 28, 2019	Jun. 30, 2018
Document Information [Line Items]
Entity Registrant Name	KEMPHARM, INC
Entity Central Index Key	1,434,647
Trading Symbol	kmph
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Emerging Growth Company	true
Entity Small Business	true
Entity Common Stock, Shares Outstanding (in shares)		26,455,352
Entity Public Float			$ 71,917,131
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Shell Company	false
Entity Ex Transition Period	true

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 18,409	$ 10,871
Marketable securities	3,260	31,358
Trade date receivables		2,005
Prepaid expenses and other current assets	2,052	1,662
Total current assets	23,721	45,896
Property and equipment, net	1,753	2,004
Long-term investments		3,250
Restricted cash	710	1,100
Other long-term assets	562	206
Total assets	26,746	52,456
Liabilities and stockholders’ deficit
Accounts payable and accrued expenses	8,342	7,875
Current portion of convertible notes	3,333	3,333
Current portion of capital lease obligation	214	189
Other current liabilities	115	112
Total current liabilities	12,004	11,509
Convertible notes, less current portion, net	78,105	89,398
Derivative and warrant liability	2,118	7,709
Capital lease obligation, less current portion	396	562
Other long-term liabilities	689	794
Total liabilities	93,312	109,972
Commitments and contingencies (Note G)
Stockholders' deficit:
Common stock, $0.0001 par value, 250,000,000 shares authorized, 26,455,352 shares issued and outstanding as of December 31, 2018; 14,657,430 shares issued and outstanding as of December 31, 2017	3	1
Additional paid-in capital	154,623	107,209
Accumulated deficit	(221,192)	(164,726)
Total stockholders' deficit	(66,566)	(57,516)
Total liabilities and stockholders' deficit	26,746	52,456
Series A Convertible Preferred Stock [Member]
Stockholders' deficit:
Preferred stock
Undesignated Preferred Stock [Member]
Stockholders' deficit:
Preferred stock

Balance Sheets (Parentheticals)

Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	9,577
Preferred stock, shares outstanding (in shares)	3,337
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	26,455,352	14,657,430
Common stock, shares outstanding (in shares)	26,455,352	14,657,430
Series A Convertible Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	9,578	0
Preferred stock, shares issued (in shares)	9,577	0
Preferred stock, shares outstanding (in shares)	3,337	0
Undesignated Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	9,990,422	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Statements of Operations

Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue
Operating expenses:
Research and development	41,759	20,593
General and administrative	12,508	12,773
Severance expense	1,636
Total operating expenses	55,903	33,366
Loss from operations	(55,903)	(33,366)
Other (expense) income:
Gain on extinguishment of debt	2
Interest expense related to amortization of debt issuance costs and discount	(1,618)	(1,561)
Interest expense on principal	(5,469)	(5,776)
Fair value adjustment related to derivative and warrant liability	5,976	(3,091)
Interest and other income, net	420	365
Total other (expense) income	(689)	(10,063)
Loss before income taxes	(56,592)	(43,429)
Income tax benefit	126	43
Net loss	$ (56,466)	$ (43,386)
Net loss per share:
Basic and diluted (in dollars per share)	$ (3.15)	$ (2.96)
Weighted average number of shares of common stock outstanding:
Basic and diluted (in shares)	17,930,023	14,652,898

Statements of Changes in Stockh

Statements of Changes in Stockholders' Deficit - USD ($)	ATM Agreement Sales [Member]Series A Convertible Preferred Stock [Member]	ATM Agreement Sales [Member]Undesignated Preferred Stock [Member]	ATM Agreement Sales [Member]Common Stock [Member]	ATM Agreement Sales [Member]Additional Paid-in Capital [Member]	ATM Agreement Sales [Member]Retained Earnings [Member]	ATM Agreement Sales [Member]	Deerfield Convertible Notes [Member]Series A Convertible Preferred Stock [Member]	Deerfield Convertible Notes [Member]Undesignated Preferred Stock [Member]	Deerfield Convertible Notes [Member]Common Stock [Member]	Deerfield Convertible Notes [Member]Additional Paid-in Capital [Member]	Deerfield Convertible Notes [Member]Retained Earnings [Member]	Deerfield Convertible Notes [Member]	Underwriting Public Offering [Member]Series A Convertible Preferred Stock [Member]	Underwriting Public Offering [Member]Undesignated Preferred Stock [Member]	Underwriting Public Offering [Member]Common Stock [Member]	Underwriting Public Offering [Member]Additional Paid-in Capital [Member]	Underwriting Public Offering [Member]Retained Earnings [Member]	Underwriting Public Offering [Member]	Convertible Notes 2021 [Member]Series A Convertible Preferred Stock [Member]	Convertible Notes 2021 [Member]Undesignated Preferred Stock [Member]	Convertible Notes 2021 [Member]Common Stock [Member]	Convertible Notes 2021 [Member]Additional Paid-in Capital [Member]	Convertible Notes 2021 [Member]Retained Earnings [Member]	Convertible Notes 2021 [Member]	Series A Convertible Preferred Stock [Member]	Undesignated Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2016																											$ 1,000	$ 102,643,000	$ (121,340,000)	$ (18,696,000)
Net loss																													(43,386,000)	(43,386,000)
Stock-based compensation expense																												4,562,000		4,562,000
Exercise of stock options and warrants																												4,000		4,000
Exercise of stock options																														7,000
Balance at Dec. 31, 2017																											1,000	107,209,000	(164,726,000)	(57,516,000)
Net loss																													(56,466,000)	(56,466,000)
Stock-based compensation expense																												6,495,000		6,495,000
Issuance of common stock in connection with ATM, net of commissions			$ 1,000	$ 4,827,000		$ 4,828,000									$ 1,000	$ 23,499,000		$ 23,500,000
Offering expenses charged to equity																												(554,000)		(554,000)
Conversion of principal and interest on Deerfield Convertible Note										$ 3,502,000		$ 3,502,000										$ 9,577,000		$ 9,577,000
Exercise of stock options																												68,000		68,000
Balance at Dec. 31, 2018																											$ 3,000	$ 154,623,000	$ (221,192,000)	$ (66,566,000)

Statements of Cash Flows

Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (56,466,000)	$ (43,386,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on extinguishment of debt	(2,000)
Write-off of deferred offering costs		60,000
Stock-based compensation expense	6,495,000	4,562,000
Non-cash interest expense	2,089,000	2,222,000
Amortization of debt issuance costs and debt discount	1,618,000	1,561,000
Depreciation and amortization expense	324,000	336,000
Fair value adjustment related to derivative and warrant liability	(5,976,000)	3,091,000
Loss on sublease and disposal of fixed assets		104,000
Change in assets and liabilities:
Prepaid expenses and other assets	(548,000)	(926,000)
Accounts payable and accrued expenses	(1,635,000)	(801,000)
Other liabilities	(102,000)	77,000
Net cash used in operating activities	(54,203,000)	(33,100,000)
Cash flows from investing activities:
Purchases of property and equipment	(21,000)	(181,000)
Purchases of marketable securities and long-term investments		(27,378,000)
Maturities and sales of marketable securities	33,353,000	54,971,000
Net cash provided by investing activities	33,332,000	27,412,000
Cash flows from financing activities:
Proceeds from underwritten public offering, net of commissions	23,500,000
Proceeds from at-the-market offering, net of commissions	4,828,000
Repayment of obligations under capital lease	(193,000)	(157,000)
Payment of deferred offering costs	(184,000)	(50,000)
Proceeds from exercise of common stock options and warrants	68,000	4,000
Net cash provided by (used in) financing activities	28,019,000	(203,000)
Net increase (decrease) in cash, cash equivalents and restricted cash	7,148,000	(5,891,000)
Cash, cash equivalents and restricted cash, beginning of year	11,971,000	17,862,000
Cash, cash equivalents and restricted cash, end of year	19,119,000	11,971,000
Supplemental cash flow information:
Cash paid for interest	5,593,000	5,717,000
Trade date receivables		2,005,000
Deerfield Convertible Note principal and interest converted to common stock	3,502,000
Property and equipment financed under a lease agreement	52,000	284,000
Property and equipment included in accounts payable and accrued expenses		3,000
Deferred offering costs included in accounts payable and accrued expenses	181,000
Exchanged 2021 Notes for Series A Preferred Stock [Member]
Supplemental cash flow information:
2021 Notes principal converted to preferred stock	$ 9,577,000

Note A - Description of Busines

Note A - Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Business Description and Basis of Presentation [Text Block]	A. Description of Business and Basis of Presentation Organization KemPharm, Inc. (the “Company”) is a specialty pharmaceutical company focused on the discovery and development of proprietary prodrugs to treat serious medical conditions through its proprietary Ligand Activated Therapy ("LAT") technology. The Company utilizes its proprietary LAT technology to generate improved prodrug versions of U.S. Food and Drug Administration (the "FDA") approved drugs as well as to generate prodrug versions of existing compounds that may October 30, 2006 May 30, 2014. Going Concern The financial statements have been prepared on a going concern basis which assumes that the Company will be able to realize its assets and discharge its liabilities in the normal course of business for the foreseeable future. The Company has experienced recurring losses from operations, negative operating cash flows and has a stockholders' deficit and its existing cash and cash equivalents, restricted cash and marketable securities are not one December 31, 2018. may may may not Management believes these conditions raise substantial doubt about the Company’s ability to continue as a going concern within the twelve Management intends to finance operating costs over the next twelve 3 $150.0 31, 2018, $120.1 3 $50.0 10 31, 2018 I.B.6. 3, twelve twelve I.B.6. not one third 60 I.B.6. 3 $18.5 $15.3 $3.2 3 twelve As discussed below, the Company sold shares of its common stock through an at-the-market offering and an underwritten public offering which resulted in gross proceeds of $4.9 $25.0 Entry into First ATM Agreement On October 3, 2016, September 14, 2018. 762,338 $4.9 three 3.0% Entry into Second ATM Agreement On September 4, 2018, may $50,000,000 3 October 17, 2016. 3 $50,000,000 I.B.6 3 $3.2 RBCCM may 415 1933, may three 3.0% The Company is not December 31, 2018, not Underwritten Public Offering On October 5, 2018, October 10, 2018, 8,333,334 3, October 17, 2016, October 17, 2016 October 5, 2018, $3.00 $23.1 Entry into Purchase Agreement On February 28, 2019, may $15.0 36 120,200 may 3 The Company is not 120,200

Note B - Summary of Significant

Note B - Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Significant Accounting Policies [Text Block]	B. Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires the Company to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, includ ing those related to the useful lives of property and equipment, and assumptions used for purposes of determining stock-based compensation, income taxes, and the fair value of the derivative and warrant liability, among others. The Company bases its estimates on historical experience and on various other assumptions that it believes to be reasonable, the results of which form the basis for making judgments about the carrying value of assets and liabilities. Concentration of Credit Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist principally of cash on deposit with multiple financial institutions, the balances of which frequently exceed insured limits. Cash and Cash Equivalents The Company considers any highly liquid investm ents with an original maturity of three Marketable Securities and Long-term Investments The Company maintains investment securities that are classified as trading securities. These securities are carried at fair value with unreali zed gains and losses included in other (expense) income on the statements of operations. The securities primarily consist of certificates of deposit, U.S. Treasury securities and U.S. government-sponsored agency securities. Property and Equipment The Company records property and equipment at cost less accumulated depreciation and amortization. Costs of renewals and improvements that extend the useful lives of the assets are capitalized. Maintenance and repairs are expensed as incurred. Depreciation is determined on a straight-line basis over the estimated useful lives of the assets, which generally range from three ten Debt Issuance Costs Debt issuance costs incurred in connection with financing arrangements are amortiz ed over the life of the respective financing arrangement using the effective interest method. Supply Arrangements The Company enters into supply arrangements for the supply of components of its product and product candidates. These arrangements also may share of future revenue if related product or product candidates reach commercialization. Costs under these supply arrangements, if any, are expensed as incurred (Note H). Impairment of Long-Lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not No December 31, 2018 2017. Fair Value of Financial Instruments The accounting standard for fair value measurements provides a framework for measuring fair value and requires disclosures regarding fair value measurements. Fair value is defined as 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, based on the Company’s principal or, in absence of a principal, most advantageous market for the specific asset or liability. The Company uses a three equent to their initial measurement. The hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs, when determining fair value. The three ● Level 1 —Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets; ● Level 2 —Observable inputs other than quoted prices in active markets that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and ● Level 3 —Unobservable inputs that are supported by little or no Research and Development Major components of research and development costs include cash compensation, stock-based compensation, depreciation and amortization expense on research and development property and equipment, costs of preclinical studies, clin ical trials and related clinical manufacturing, costs of drug development, costs of materials and supplies, facilities cost, overhead costs, regulatory and compliance costs, and fees paid to consultants and other entities that conduct certain research and development activities on the Company’s behalf. Costs incurred in research and development are expensed as incurred. The Company records nonrefundable advance payments it makes for future research and development activities as prepaid expenses. Prepaid expenses are recognized as expense in the statements of operations as the Company receives the related goods or services. The Company enters into contractual agreements with third pleted over an extended period of time. The Company records liabilities under these contractual commitments when an obligation has been incurred. This accrual process involves reviewing open contracts and purchase orders, communicating with the applicable personnel to identify services that have been performed and estimating the level of service performed and the associated cost when the Company has not Patent Costs Patent costs, including related legal costs, are expensed as incurred and recorded within general and administrative expenses on the statements of operations. Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax basis of assets and liabilities, as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using the tax rates that are expected to apply to taxable income for the years in which those tax assets and liabilities are expected to be realized or settled. Valuation allowances are recorded to reduce deferred tax assets to the amount the Company believes is more likely than not Uncertain tax positions are recognized only when the Company believes it is more likely than not t the tax position will be upheld on examination by the taxing authorities based on the merits of the position. The Company recognizes interest and penalties, if any, related to unrecognized income tax uncertainties in income tax expense. The Company did not December 31, 2018 2017. The Company files income tax returns in the United States for federal and various state jurisdictions. With few exceptions, the Company is no 2014, 2014 may No Stock-Based Compensation The Company measures and recognizes compensation expense for all stock-based payment awards made to employees, officers an d directors based on the estimated fair values of the awards as of the grant date. The Company records the value of the portion of the award that is ultimately expected to vest as expense over the requisite service period. The Company also accounts for equity instruments issued to non-employees using a fair value approach under Accounting Standards Codification ("ASC") subtopic 505 50. Basic and Diluted Net Loss per Share of Common Stock The Company uses the two entitle the holders to participate in dividends and earnings of the Company. The two Segment and Geographic Information Operating segments are defined as components of an enterprise (business activity from which it earns revenue and incurs expenses) for which discrete financial information is ava ilable and regularly reviewed by the chief operating decision maker ("CODM") in deciding how to allocate resources and in assessing performance. The Company’s CODM is its Chief Executive Officer. The Company views its operations and manages its business as a single operating and reporting segment. All assets of the Company were held in the United States as of December 31, 2018 2017. Application of New or Revised Accounting Standards —Adopted From time to time, the Financial Accounting Standards Board (the “FASB”) or other standard-setting bodies issue accounting standards that are adopted by the Company as of the specified effective date . On April 5, 2012, JOBS Act”) into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an emerging growth company. As an emerging growth company, the Company may not In May 2014, 606, Revenue Recognition—Revenue from Contracts with Customers 606" 605, Revenue Recognition January 1, 2018. not not In January 2016, 2016 01, Financial Instruments Overall – Recognition and Measurement of Financial Assets and Liabilities (Topic 825 - 10 ) 2016 01” 825 10. December 15, 2017, 2016 01 not In August 2016, 2016 15, Statement of Cash Flows – Classification of Certain Cash Receipts and Cash Payments (Topic 230 ) 2016 15” eight 230. December 15, 2017, 2016 15 not In May 2017, 2017 09, Compensation – Stock Compensation (Topic 718 ) – Scope of Modification Accounting 2017 09" 718. December 15, 2017, 2017 09 not Application of New or Revised Accounting Standards —Not In February 2016, 2016 02, Leases (Topic 842 ) 2016 02” January 1, 2019 not 12 $3.0 January 1, 2019. In July 2017, 2017 - 11, Earnings Per Share (Topic 260 ), Distinguishing Liabilities from Equity (Topic 480 ), Derivatives and Hedging (Topic 815 ) – I. Accounting for Certain Financial Instruments with Down Round Features and II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception ("ASU 2017 - 11" 480 because of the existence of extensive pending content in the ASC as a result of the indefinite deferral of accounting requirements about mandatorily redeemable financial instruments of certain nonpublic entities and certain mandatorily redeemable noncontrolling interests. This update applies to all entities that issue financial instruments that include down round features and entities that present earnings per share in accordance with Topic 260. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, not 2017 11 In June 2018, 2018 07, Compensation – Stock Compensation (Topic 820 2018 07" 718, December 15, 2018, 718 718 718 no 606. not 2018 07 In August 2018, 2018 13, Fair Value Measurement (Topic 820 2018 13" 820, Conceptual Framework for Financial Reporting—Chapter 8: August 28, 2018, December 15, 2019, 3 2018 13

Note C - Prepaid Expenses and O

Note C - Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Other Current Assets [Text Block]	C. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): December 31, 2018 2017 Prepaid insurance $ 224 $ 202 Other receivables 140 76 Other prepaid expenses and current assets 1,688 1,384 Total prepaid expenses and other current assets $ 2,052 $ 1,662

Note D - Property and Equipment

Note D - Property and Equipment	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	D. Property and Equipment Property and equipment consists of the following (in thousands): December 31, 2018 2017 Laboratory equipment $ 1,035 $ 983 Furniture and office equipment 655 655 Computers and hardware 299 292 Leasehold improvements 1,017 1,003 Total property and equipment 3,006 2,933 Less: accumulated depreciation and amortization (1,253 ) (929 ) Property and equipment, net $ 1,753 $ 2,004 The Company leases various equipment and leasehold improvements under capital lease agreements. The assets under capital leases are included in property and equipment as follows (in thousands): December 31, 2018 2017 Laboratory equipment $ 418 $ 366 Furniture and office equipment 541 541 Leasehold improvements 59 59 Total property and equipment financed under a capital lease agreement 1,018 966 Less: accumulated depreciation and amortization (272 ) (150 ) Property and equipment financed under a capital lease agreement, net $ 746 $ 816 The estimated useful lives of property and equipment are as follows: Useful Life Asset Category (in years) Laboratory equipment 10 Furniture and office equipment 5 - 10 Computers and hardware 3 - 7 Leasehold improvements 9 Depreciation and amortization expense, including amounts pertaining to assets held under capital leases, was approximately $324,000 $336,000 December 31, 2018 2017,

Note E - Accounts Payable and A

Note E - Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	E. Accounts Payable and Accrued Expenses Accounts payable and accrued expenses consist of the following (in thousands): December 31, 2018 2017 Accrued interest $ 1,921 $ 2,222 Accrued banking fees 700 700 Accrued severance 193 — Accrued payroll 731 1,118 Accounts payable 3,715 2,177 Other accrued expenses 1,082 1,658 Total accounts payable and accrued expenses $ 8,342 $ 7,875

Note F - Debt Obligations

Note F - Debt Obligations	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Debt Disclosure [Text Block]	F. Debt Obligations Deerfield Facility Agreement On June 2, 2014, $60 first $15 $10 June 30, 2016, no 9.75% may $5.85 The Company also issued to Deerfield a warrant to purchase 14,423,076 Series D Preferred”) at an exercise price of $0.78 June 2, 2024 1,923,077 $5.85 260, Earnings per Share, may one third 12 1934, In addition, the Company issued to Deerfield 1,923,077 256, 410 $1.5 in the statements of operations. Pursuant to the Deerfield Fac ility Agreement, the Company may not $750,000 The Company must repay one third fourth fifth February 14, 2020. February 2016. fourth "Facility Agreement Waiver and Fifth Amendment to Senior Secured Convertible Note" Interest accrued on outstanding debt under the Deerfield Fa cility Agreement is due quarterly in arrears. Upon notice to Deerfield, the Company had the option to have one first eight July 1, 2016. eight June 30, 2016. July 1, 2016. First Amendment to Facility Agreement, Senior Secured Convertible Note and Warrant In connection with the IPO, on March 6, 2015, Second Amendment to Senior Secured Convertible Note and Warrant On January 6, 2016, Issuance of 5.50% Notes and Third Amendment to Senior Secured Convertible Note and Warrant On February 9, 2016, $86.3 5.50% 2021 2021 2021 144A The net proceeds from the Note Offering were approximately $82.8 ’ discount and estimated offering expenses. Concurrent with the Note Offering, the Company used approximately $18.6 The 2021 February 9, 2016 2021 February 1 August 1 August 1, 2016, 5.50% 2021 February 1, 2021 2021 not no 2021 The 2021 58.4454 ’s common stock per $1,000 2021 $17.11 2021 not 2021 If the Company undergoes a “ fundamental change” (as defined in the Indenture), holders may 2021 100% 2021 2021 one 2021 may The Indenture includes customary terms and covenants, including certain events of default after which the 2021 may In connection with the Note Offering, on February 3, 2016, 2021 Refer to the section entitled Exchange Agreement below for a further discussion of an exchange of a certain portion of the 2021 $0.0001 Fourth Amendment to Senior Secured Convertible Note and Warrant In connection with entering into the ATM Agreement, on October 3, 2016, 415 Facility Agreement Waiver and Fifth Amendment to Senior Secured Convertible Note On June 11, 2018, $3,333,333 $168,288 598,568 June 2, 2018; ( Exchange Agreement On October 5, 2018, $9,577,000 2021 9,577 $95,105 $25,000 As a condition to closing of the Exchange Agreement, the Company filed a Certificate of Designation of Preferences, Rights and Limitations of Series A Convertible Preferred Stock (the “Certificate of Designation”) with the Secretary of State of the State Delaware, setting forth the preferences, rights and limitations of the Series A Preferred Stock. Each share of Series A Preferred Stock has an aggregate stated value of $1,000 $3.00 3,192,334 4.985% not $0.0001 not not not First Supplemental Indenture, Sixth Amendment to Deerfield Convertible Note and Fifth Amendment to Deerfield Warrant On November 20, 2018, 2021 2021 not 9.985% three 3 may Also on November 20, 2018, 4.985% 2021 4.985%. Seventh Amendment to Deerfield Convertible Note and Sixth Amendment to Deerfield Warrant On February 28, 2019, not may Except as modified by the First Amendment, Second Amendment, Third Amendment, Fourth Amendment, Fifth Amendment, Sixth Amendment and Seventh Amendment, all terms and conditions of the Deerfield Facility Agreement, Deerfield Warrant and Deerfield Convertible Note remained in full force and effect. Convertible Notes Future minimum principal payments under convertible notes as of December 31, 2018, Convertible Year Ending December 31, Notes 2019 3,333 2020 3,334 2021 76,673 Total minimum principal payments 83,340 Less: debt issuance costs and discount (1,902 ) Convertible notes, net $ 81,438 Line of Credit During the second 2016, line of credit with a total borrowing capacity of $1.1 December 31, 2018 and 2017, $0.4 January 31, 2018. January 31, 2018, two January 31, 2020. December 31, 2018 and 2017, no no 1 2.00% 4.35 December 31, 2018.

Note G - Commitments and Contin

Note G - Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	G. Commitments and Contingencies Legal Matters From time to time, the Company is involved in various legal proceedings arising in the normal course of business. For some matters, a liability is not not December 31, 2018 2017, no . Lease Agreements Florida The Company leases office space in Florida, comprised of two non-cancelable operating leases, which expire in August 2025 February 2026, two five Iowa The Company leases office and laboratory facilities in Iowa under a non-cancelable operating lease. The Company’s lease for its Iowa facilities expires in September 2019 one Virginia The Company leases office and laboratory facilities in Virginia under a non-cancelable operating lease. The Company’s lease for its Virginia facilities expires in August 2019. North Carolina The Company leases office space in North Carolina under a non-cancelable operating lease. The expiration date of the Company ’s lease is May 2020, three second 2017, third third Capital Lease The Company leases various laboratory equipment, furniture and office equipment and leasehold improvements that are accounted for as capital leases and that require ongoing payments, including interest expense. The capital leases are financed through various financial institutions and are collateralized by the underlying assets. As of December 31, 2018 and 2017, 7.19% 9.57 Rent expense for non-cancelable operating leases was $0.7 million and $0.6 December 31, 2018 2017, Future minimum lease payments under capital leases and non-cancelable operating leases as of December 31, 2018, Capital Operating Year Ending December 31, Leases Leases 2019 $ 254 $ 714 2020 251 499 2021 163 449 2022 11 461 2023 — 472 Thereafter — 903 Total minimum lease payments 679 $ 3,498 Less: amounts representing interest (69 ) Total minimum capital lease principal payments $ 610

Note H - Supply Arrangement

Note H - Supply Arrangement	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Collaborative Arrangement Disclosure [Text Block]	H. Supply Arrangement As of December 31, 2018 and 2017, one potential future expenditures related to research and development. In November 2009, Supply Agreement”) with Johnson Matthey Inc. (“JMI”) whereby JMI has agreed to supply the Company with all of the benzhydrocodone necessary for clinical trials and commercial sale for a price equal to JMI’s manufacturing cost and to provide process optimization and development services for benzhydrocodone. The Company’s FDA-approved drug, APADAZ, contains benzhydrocodone. Expense of $3.6 31, 2018. No December 31, 2017 tenth two 12 not No

Note I - Preferred Stock and Wa

Note I - Preferred Stock and Warrants	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Preferred Stock [Text Block]	I. Preferred Stock and Warrants Authorized, Issued, and Outstanding Preferred Stock As of December 31, 2018, 10,000,000 9,578 9,577 31, 2018 3,337 31, 2017, 10,000,000 On October 5, 2018, 9,577 $1,000 $3.00 3,192,334 4.985% not $0.0001 not not not February 28, 2019, 6,240 2,080,000 As of February 28, 2019, 3,337 1,112,334 Warrants During 2013, $3.8 million of convertible notes and the warrants (the “2013 1,079,453 2013 2013 1,079,453 2013 143,466 $5.85 2013 June 2, 2019, On June 2, 2014, d Facility Agreement, the Company issued the Deerfield Warrant to purchase 14,423,076 June 2, 2024, 1,923,077 $5.85 The Company determined that the 2013 ty and stated at fair value at each reporting period upon inception. As stated above, upon completion of the IPO, the 2013 2013

Note J - Common Stock and Warra

Note J - Common Stock and Warrants	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	J. Common Stock and Warrants Authorized, Issued, and Outstanding Common Shares As of December 31, 2018 2017, authorized shares of common stock of 250,000,000 26,455,352 14,657,430 December 31, 2018 2017, As of Dec ember 31, 2018 2017, December 31, 2018 2017 Conversion of Deerfield Convertible Note 1,167,607 1,751,410 Conversion of 2021 Notes 4,481,182 5,040,914 Outstanding awards under equity incentive plans 3,704,755 2,853,924 Outstanding common stock warrants 2,527,763 2,027,763 Conversion of Series A Convertible Preferred Stock 1,112,334 — Possible future issuances under equity incentive plans 648,272 944,700 Total common shares reserved for future issuance 13,641,913 12,618,711 Common Stock Activity The following table summarizes common stock activity for the years ended December 31, 2018 and 2017 Shares of Common Stock Balance as of January 1, 2017 14,646,982 Common stock warrants exercised 698 Common stock options exercised 9,750 Balance as of December 31, 2017 14,657,430 Common stock sold under First ATM Agreement 762,338 Common stock issued as a result of Deerfield Convertible Note principal and interest conversion 598,568 Common stock options exercised 23,682 Common stock sold under underwritten public offering 8,333,334 Common stock issued as a result of Series A Convertible Preferred Stock conversion 2,080,000 Balance as of December 31, 2018 26,455,352 On September 4, 2018, 762,338 $4.9 February 28, 2019, not On October 5, 2018, 8,333,334 3. Also on October 5, 2018, 9,577 February 28, 2019, 6,240 2,080,000 Warrants The Company calculates the fair value of common stock warrants (other than the KVK Warrant, as defined below) using a Monte Carlo simulation. There were warrants exercised for an aggregate of 698 December 31, 2017. No December 31, 2018. 2008 2012, 595,920 second second 2017. In connection with a Collaboration and License Agreement (the “License Agreement”) with KVK Tech, Inc. (“KVK”), on October 25, 2018, 500,000 $2.30 October 25, 2018 ( not four 125,000 four 500,000 October 24, 2023. may The Company determined that, since KVK qualifies as a customer under ASC 606, 815 815 606

Note K - Stock-based Compensati

Note K - Stock-based Compensation	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	K. Stock-Based Compensation The Company maintains a stock-based compensation plan (the “ Incentive Stock Plan”) that governs stock awards made to employees and directors prior to completion of the IPO. In November 2014, April 2015, ’s stockholders, approved the Company’s 2014 “2014 April 2015. 2014 may 2014 4,018,480 December 31, 2018. 2014 January 1 January 1, 2016, January 1, 2024, 4% December 31 2014 January 1, 2019, 2014 1,058,214 During the years ended December 31, 2018 2017, 23,682 9,750 $68,000 $7,000 $69,000 $32,000, Stock-based compensation expense recorded unde r the Incentive Stock Plan and the 2014 Year Ended December 31, 2018 2017 Research and development $ 1,608 $ 1,304 General and administrative 3,651 3,258 Severance expense 1,236 — Total stock-based compensation expense $ 6,495 $ 4,562 Stock Option Awards The Company estimates the fair value of stock options using the Black-Scholes option-pricing model, which requires the use of subjective assumptions, including the expected term of the option, the expected stock price volatility, expe cted dividend yield and the risk-free interest rate for the expected term of the option. The expected term represents the period of time the stock options are expected to be outstanding. Due to the lack of sufficient historical exercise data to provide a reasonable basis upon which to otherwise estimate the expected term of the stock options, the Company uses the simplified method to estimate the expected term for its “plain vanilla” stock options. Under the simplified method, the expected term of an option is presumed to be the mid-point between the vesting date and the end of the contractual term. Some options, for example those that have exercise prices in excess of the fair value of the underlying stock, are not second ies and the Company over the estimated expected term of the stock options. second The Company assumes no not not The Company recogni zes compensation expense related to stock-based payment transactions upon satisfaction of the requisite service or vesting requirements. Forfeitures are estimated at the time of grant and revised based on actual forfeitures, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Using the Black-Scholes option-pricing model, the weighted-average fair value of awards granted during the years ended December 31, 2018 2017, $4.05 $2.77 re, respectively. The assumptions used to estimate fair value are as follows: December 31, 2018 2017 Risk-free interest rate 2.43% - 2.91% 1.88% - 2.26% Expected term (in years) 5.50 - 6.79 5.12 - 7.00 Expected volatility 83.10% - 85.05% 85.35% - 95.08% Expected dividend yield 0% 0% The activity under the Incentive Stock Plan and the 2014 for the year ended December 31, 2018, Weighted Average Number of Weighted Average Remaining Contractual Aggregate Intrinsic Options Exercise Price Term (in years) Value Outstanding balance as of January 1, 2018 2,853,924 $ 10.50 7.90 $ 471,539 Granted 898,000 $ 5.54 Exercised (23,682 ) $ 3.15 Canceled or forfeited (20,821 ) $ 10.63 Expired (2,666 ) $ 3.00 Outsta nding balance as of December 31, 2018 3,704,755 $ 9.35 7.48 $ — Exercisable as of December 31, 2018 1,837,582 $ 11.56 6.67 $ — Vested and expected to vest as of December 31, 2018 3,656,474 $ 9.40 7.47 $ — Information regarding currently outstanding and exercisable options as of December 31, 2018, Options Outstanding Options Exercisable Weighted Average Weighted Average Number of Remaining Contractual Number of Remaining Contractual Exercise Price Shares Term (in years) Shares Term (in years) $2.75 to $5.00 1,024,995 7.89 390,244 7.59 $5.01 to $10.00 1,256,427 7.85 437,527 5.50 $10.01 to $15.00 471,833 6.94 285,249 6.85 $15.01 to $20.00 603,700 6.89 463,712 6.88 $20.01 to $22.12 347,800 6.68 260,850 6.68 3,704,755 7.48 1,837,582 6.67 The total fair value of stock options vested during the years ended December 31, 2018 2017, $5.9 $4.1 Unvested stock options as of December 31, 2018 2017, Number of Unvested Shares December 31, Exercise Price 2018 2017 $2.75 to $5.00 634,751 979,000 $5.01 to $10.00 818,900 21,301 $10.01 to $15.00 186,584 282,542 $15.01 to $20.00 139,988 352,789 $20.01 to $22.12 86,950 173,900 Total number of unvested shares 1,867,173 1,809,532 As of December 31, 2018, $6.0 ncentive Stock Plan and 2014 1.84 There was no December 31, 2018 or 2017.

Note L - Fair Value of Financia

Note L - Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	L. Fair Value of Financial Instruments The carrying amounts of certain financial instruments, including cash and cash equivalents, restricted cash and accounts payable and accrued expenses, approximate their respective fair values due to the short-term nature of such instruments. The fair value of the Deerfield Convertible Note was $6.2 $11.0 December 31, 2018 2017. 2021 $51.2 $51.9 December 31, 2018 2017. 2021 3 2021 as of December 31, 2018 2017. Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in whi ch to classify them for each reporting period. This determination requires significant judgments to be made. The following table summarizes the conclusions reached regarding fair value measurements as of December 31, 2018 2017 Quoted Prices in Significant Balance as of Active Markets Significant Other Unobservable December 31, for Identical Assets Observable Inputs Inputs 2018 (Level 1) (Level 2) (Level 3) Deerfield Warrant liability $ 1,557 $ — $ — $ 1,557 Embedded Warrant Put Option 154 — — 154 Fundamental change and make-whole interest provisions embedded in 2021 Notes — — — — Deerfield Note Conversion Feature 134 — — 134 KVK Warrant liability 273 — 273 — Total liabilities $ 2,118 $ — $ 273 $ 1,845 Trading securities: Certificates of deposit 246 246 — — U.S. Treasury securities 3,014 3,014 — — Total assets $ 3,260 $ 3,260 $ — $ — Quoted Prices in Significant Balance as of Active Markets Significant Other Unobservable December 31, for Identical Assets Observable Inputs Inputs 2017 (Level 1) (Level 2) (Level 3) Deerfield Warrant liability $ 5,115 $ — $ — $ 5,115 Embedded Warrant Put Option 365 — — 365 Fundamental change and make-whole interest provisions embedded in 2021 Notes 14 — — 14 Deerfield Note Conversion Feature 2,215 2,215 Total liabilities $ 7,709 $ — $ — $ 7,709 Trading securities: Certificates of deposit 5,616 5,616 — — U.S. Treasury securities 25,988 25,988 — — U.S. government-sponsored agency securities 3,004 — 3,004 — Total assets $ 34,608 $ 31,604 $ 3,004 $ — The Company ’s Deerfield Warrant liability, embedded Warrant Put Option, the fundamental change and the make-whole interest provisions embedded in the 2021 December 31, 2018 2017, 2021 2021 December 31, 2018 2017. 2021 31, 2018 2017 fair value adjustment related to derivative and warrant liability. The Company’s KVK Warrant liability is measured at fair value on a recurring basis. As of December 31, 2018, no not not December 31, 2018 no December 31, 2017 October 2018. A reconciliation of the beginning and ending balances for the derivative and warrant liability measured at fair value on a recurring basis using signific ant unobservable inputs (Level 3 2018 2017 Balance as of beginning of period $ 7,709 $ 4,618 Gain on extinguishment of debt (2 ) — Adjustment to fair value (5,862 ) 3,091 Balance as of end of period $ 1,845 $ 7,709

Note M - Income Taxes

Note M - Income Taxes	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	M. Income Taxes The Company ’s financial statements include a total state tax benefit related to research and development credits of $126,000 $43,000 $56.6 $43.4 December 31, 2018 2017, Year ended December 31, 2018 2017 Federal statutory rate 21.00 % 34.00 % Effect of: Change in valuation allowance (30.44 ) 13.38 Return to provision and deferred true-up 0.38 2.18 Change in rate 0.03 (49.06 ) State tax benefit (net of federal) 4.35 2.71 Warrant liability 2.02 (2.42 ) State research and development credit 0.22 0.10 Federal research and development credit 3.30 1.50 Amortization — (1.22 ) Stock-based compensation (0.63 ) (1.03 ) Other (0.01 ) (0.04 ) Federal income tax benefit effective rate 0.22 % 0.10 % The components of deferred tax assets and liabilities are as follows (in thousands): December 31, 2018 2017 Deferred tax assets relating to: Net operating loss carryforwards $ 51,269 $ 37,028 Research and development tax carryforward 5,657 3,788 Other deferred tax assets 3,437 2,409 Total gross deferred tax assets 60,363 43,225 Deferred tax liabilities relating to: Property and equipment 161 260 Other deferred tax liabilities 10 — Total gross deferred tax liabilities 171 260 Deferred tax assets less liabilities 60,192 42,965 Valuation allowance (60,192 ) (42,965 ) Net deferred tax asset (liability) $ — $ — H.R. 1, 2018” "2017 December 22, 2017. 2017 35% 21%, one 2017 2026 In assessing the realizability of deferred tax assets, management considers whether it is more likely than not not assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. Based upon the level of historical taxable income and projections for future taxable income over the periods in which the deferred tax assets are deductible, management believes it is more likely than not not The Company had the following federal net operating loss carryforward and research activities credits as of December 31, 2018 ( Net Research Operating Loss Activities Year Incurred Carryforwards Credit Expiration 2007 $ 454 $ 30 2027 2008 1,178 65 2028 2009 3,060 176 2029 2010 3,423 149 2030 2011 9,929 176 2031 2012 — 170 2032 2013 4,353 133 2033 2014 15,897 894 2034 2015 23,496 598 2035 2016 41,580 745 2036 2017 34,776 652 2037 2018 56,105 1,869 Indefinite $ 194,251 $ 5,657 The Company also has certain state net operating loss carryforwards totaling $136.0 2027 2037. may 382 may imitations on the Company’s ability to utilize the net operating loss carryforward. ASC 740 10, Accounting for Uncertainty in Income Taxes not” not not not not

Note N - Net Loss Per Share

Note N - Net Loss Per Share	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Earnings Per Share [Text Block]	N. Net Loss Per Share Under the two is computed by dividing the net income attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Net income attributable to common stockholders is computed by subtracting from net income the portion of current year earnings that participating securities would have been entitled to receive pursuant to their dividend rights had all of the year’s earnings been distributed. No no two two The following table summarizes the computation of basic and diluted net loss and net loss per share of the Company (in thousands, except share and pe r share amounts): Year ended December 31, 2018 2017 Net loss - basic and diluted $ (56,466 ) $ (43,386 ) Weighted average number of shares of common stock - basic and diluted 17,930,023 14,652,898 Net loss per share - basic and diluted $ (3.15 ) $ (2.96 ) Diluted net loss per share is the same as basic net loss per share for all periods presented because the effects of potentially dilutive items were anti-dilutive given the Company ’s net loss. The following securities, presented on a common stock equivalent basis, have been excluded from the calculation of weighted average number of shares of common stock outstanding because their effect is anti-dilutive: December 31, 2018 2017 Deerfield Convertible Note 1,167,607 1,751,410 2021 Notes 4,481,182 5,040,914 Awards under equity incentive plans 3,704,755 2,853,924 Warrants to purchase common stock 2,527,763 2,027,763 Series A Convertible Preferred Stock 1,112,334 — Total securities excluded from the calculation of weighted average number of shares of common stock outstanding 12,993,641 11,674,011

Note O - Severance Expense

Note O - Severance Expense	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Restructuring and Related Activities Disclosure [Text Block]	O. Severance Expense On August 31, 2018, $0.4 $1.2 December 31, 2018. December 31, 2018, $0.2

Note P - Employee Benefit Plan

Note P - Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Compensation and Employee Benefit Plans [Text Block]	P. Employee Benefit Plan The Company has a 401 401 may 4% 401 $212,000 $207,000 December 31, 2018 2017, The Company has a discretionary profit sharing plan (the “ Profit Sharing Plan”) that covers all employees. Employees become eligible participants in the Profit Sharing Plan once they have provided three no 2018 2017.

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires the Company to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, includ ing those related to the useful lives of property and equipment, and assumptions used for purposes of determining stock-based compensation, income taxes, and the fair value of the derivative and warrant liability, among others. The Company bases its estimates on historical experience and on various other assumptions that it believes to be reasonable, the results of which form the basis for making judgments about the carrying value of assets and liabilities.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentration of Credit Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist principally of cash on deposit with multiple financial institutions, the balances of which frequently exceed insured limits.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents The Company considers any highly liquid investm ents with an original maturity of three
Marketable Securities, Policy [Policy Text Block]	Marketable Securities and Long-term Investments The Company maintains investment securities that are classified as trading securities. These securities are carried at fair value with unreali zed gains and losses included in other (expense) income on the statements of operations. The securities primarily consist of certificates of deposit, U.S. Treasury securities and U.S. government-sponsored agency securities.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment The Company records property and equipment at cost less accumulated depreciation and amortization. Costs of renewals and improvements that extend the useful lives of the assets are capitalized. Maintenance and repairs are expensed as incurred. Depreciation is determined on a straight-line basis over the estimated useful lives of the assets, which generally range from three ten
Debt, Policy [Policy Text Block]	Debt Issuance Costs Debt issuance costs incurred in connection with financing arrangements are amortiz ed over the life of the respective financing arrangement using the effective interest method.
Collaborative Arrangement, Accounting Policy [Policy Text Block]	Supply Arrangements The Company enters into supply arrangements for the supply of components of its product and product candidates. These arrangements also may share of future revenue if related product or product candidates reach commercialization. Costs under these supply arrangements, if any, are expensed as incurred (Note H).
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment of Long-Lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not No December 31, 2018 2017.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments The accounting standard for fair value measurements provides a framework for measuring fair value and requires disclosures regarding fair value measurements. Fair value is defined as 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, based on the Company’s principal or, in absence of a principal, most advantageous market for the specific asset or liability. The Company uses a three equent to their initial measurement. The hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs, when determining fair value. The three ● Level 1 —Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets; ● Level 2 —Observable inputs other than quoted prices in active markets that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and ● Level 3 —Unobservable inputs that are supported by little or no
Research and Development Expense, Policy [Policy Text Block]	Research and Development Major components of research and development costs include cash compensation, stock-based compensation, depreciation and amortization expense on research and development property and equipment, costs of preclinical studies, clin ical trials and related clinical manufacturing, costs of drug development, costs of materials and supplies, facilities cost, overhead costs, regulatory and compliance costs, and fees paid to consultants and other entities that conduct certain research and development activities on the Company’s behalf. Costs incurred in research and development are expensed as incurred. The Company records nonrefundable advance payments it makes for future research and development activities as prepaid expenses. Prepaid expenses are recognized as expense in the statements of operations as the Company receives the related goods or services. The Company enters into contractual agreements with third pleted over an extended period of time. The Company records liabilities under these contractual commitments when an obligation has been incurred. This accrual process involves reviewing open contracts and purchase orders, communicating with the applicable personnel to identify services that have been performed and estimating the level of service performed and the associated cost when the Company has not
Intangible Assets, Finite-Lived, Policy [Policy Text Block]	Patent Costs Patent costs, including related legal costs, are expensed as incurred and recorded within general and administrative expenses on the statements of operations.
Income Tax, Policy [Policy Text Block]	Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax basis of assets and liabilities, as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using the tax rates that are expected to apply to taxable income for the years in which those tax assets and liabilities are expected to be realized or settled. Valuation allowances are recorded to reduce deferred tax assets to the amount the Company believes is more likely than not Uncertain tax positions are recognized only when the Company believes it is more likely than not t the tax position will be upheld on examination by the taxing authorities based on the merits of the position. The Company recognizes interest and penalties, if any, related to unrecognized income tax uncertainties in income tax expense. The Company did not December 31, 2018 2017. The Company files income tax returns in the United States for federal and various state jurisdictions. With few exceptions, the Company is no 2014, 2014 may No
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation The Company measures and recognizes compensation expense for all stock-based payment awards made to employees, officers an d directors based on the estimated fair values of the awards as of the grant date. The Company records the value of the portion of the award that is ultimately expected to vest as expense over the requisite service period. The Company also accounts for equity instruments issued to non-employees using a fair value approach under Accounting Standards Codification ("ASC") subtopic 505 50.
Earnings Per Share, Policy [Policy Text Block]	Basic and Diluted Net Loss per Share of Common Stock The Company uses the two entitle the holders to participate in dividends and earnings of the Company. The two
Segment Reporting, Policy [Policy Text Block]	Segment and Geographic Information Operating segments are defined as components of an enterprise (business activity from which it earns revenue and incurs expenses) for which discrete financial information is ava ilable and regularly reviewed by the chief operating decision maker ("CODM") in deciding how to allocate resources and in assessing performance. The Company’s CODM is its Chief Executive Officer. The Company views its operations and manages its business as a single operating and reporting segment. All assets of the Company were held in the United States as of December 31, 2018 2017.
New Accounting Pronouncements, Not Yet Adopted, Policy [Policy Text Block]	Application of New or Revised Accounting Standards —Adopted From time to time, the Financial Accounting Standards Board (the “FASB”) or other standard-setting bodies issue accounting standards that are adopted by the Company as of the specified effective date . On April 5, 2012, JOBS Act”) into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an emerging growth company. As an emerging growth company, the Company may not In May 2014, 606, Revenue Recognition—Revenue from Contracts with Customers 606" 605, Revenue Recognition January 1, 2018. not not In January 2016, 2016 01, Financial Instruments Overall – Recognition and Measurement of Financial Assets and Liabilities (Topic 825 - 10 ) 2016 01” 825 10. December 15, 2017, 2016 01 not In August 2016, 2016 15, Statement of Cash Flows – Classification of Certain Cash Receipts and Cash Payments (Topic 230 ) 2016 15” eight 230. December 15, 2017, 2016 15 not In May 2017, 2017 09, Compensation – Stock Compensation (Topic 718 ) – Scope of Modification Accounting 2017 09" 718. December 15, 2017, 2017 09 not Application of New or Revised Accounting Standards —Not In February 2016, 2016 02, Leases (Topic 842 ) 2016 02” January 1, 2019 not 12 $3.0 January 1, 2019. In July 2017, 2017 - 11, Earnings Per Share (Topic 260 ), Distinguishing Liabilities from Equity (Topic 480 ), Derivatives and Hedging (Topic 815 ) – I. Accounting for Certain Financial Instruments with Down Round Features and II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception ("ASU 2017 - 11" 480 because of the existence of extensive pending content in the ASC as a result of the indefinite deferral of accounting requirements about mandatorily redeemable financial instruments of certain nonpublic entities and certain mandatorily redeemable noncontrolling interests. This update applies to all entities that issue financial instruments that include down round features and entities that present earnings per share in accordance with Topic 260. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, not 2017 11 In June 2018, 2018 07, Compensation – Stock Compensation (Topic 820 2018 07" 718, December 15, 2018, 718 718 718 no 606. not 2018 07 In August 2018, 2018 13, Fair Value Measurement (Topic 820 2018 13" 820, Conceptual Framework for Financial Reporting—Chapter 8: August 28, 2018, December 15, 2019, 3 2018 13

Note C - Prepaid Expenses and_2

Note C - Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]	December 31, 2018 2017 Prepaid insurance $ 224 $ 202 Other receivables 140 76 Other prepaid expenses and current assets 1,688 1,384 Total prepaid expenses and other current assets $ 2,052 $ 1,662

Note D - Property and Equipme_2

Note D - Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Property, Plant and Equipment [Table Text Block]	December 31, 2018 2017 Laboratory equipment $ 1,035 $ 983 Furniture and office equipment 655 655 Computers and hardware 299 292 Leasehold improvements 1,017 1,003 Total property and equipment 3,006 2,933 Less: accumulated depreciation and amortization (1,253 ) (929 ) Property and equipment, net $ 1,753 $ 2,004
Schedule of Capital Leased Assets [Table Text Block]	December 31, 2018 2017 Laboratory equipment $ 418 $ 366 Furniture and office equipment 541 541 Leasehold improvements 59 59 Total property and equipment financed under a capital lease agreement 1,018 966 Less: accumulated depreciation and amortization (272 ) (150 ) Property and equipment financed under a capital lease agreement, net $ 746 $ 816
Property, Plant and Equipment, Useful Life [Table Text Block]	Useful Life Asset Category (in years) Laboratory equipment 10 Furniture and office equipment 5 - 10 Computers and hardware 3 - 7 Leasehold improvements 9

Note E - Accounts Payable and_2

Note E - Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	December 31, 2018 2017 Accrued interest $ 1,921 $ 2,222 Accrued banking fees 700 700 Accrued severance 193 — Accrued payroll 731 1,118 Accounts payable 3,715 2,177 Other accrued expenses 1,082 1,658 Total accounts payable and accrued expenses $ 8,342 $ 7,875

Note F - Debt Obligations (Tabl

Note F - Debt Obligations (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Maturities of Long-term Debt [Table Text Block]	Convertible Year Ending December 31, Notes 2019 3,333 2020 3,334 2021 76,673 Total minimum principal payments 83,340 Less: debt issuance costs and discount (1,902 ) Convertible notes, net $ 81,438

Note G - Commitments and Cont_2

Note G - Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block]	Capital Operating Year Ending December 31, Leases Leases 2019 $ 254 $ 714 2020 251 499 2021 163 449 2022 11 461 2023 — 472 Thereafter — 903 Total minimum lease payments 679 $ 3,498 Less: amounts representing interest (69 ) Total minimum capital lease principal payments $ 610

Note J - Common Stock and War_2

Note J - Common Stock and Warrants (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Authorized Shares of Common Stock Reserved for Future Issuance [Table Text Block]	December 31, 2018 2017 Conversion of Deerfield Convertible Note 1,167,607 1,751,410 Conversion of 2021 Notes 4,481,182 5,040,914 Outstanding awards under equity incentive plans 3,704,755 2,853,924 Outstanding common stock warrants 2,527,763 2,027,763 Conversion of Series A Convertible Preferred Stock 1,112,334 — Possible future issuances under equity incentive plans 648,272 944,700 Total common shares reserved for future issuance 13,641,913 12,618,711
Schedule of Common Stock Outstanding Roll Forward [Table Text Block]	Shares of Common Stock Balance as of January 1, 2017 14,646,982 Common stock warrants exercised 698 Common stock options exercised 9,750 Balance as of December 31, 2017 14,657,430 Common stock sold under First ATM Agreement 762,338 Common stock issued as a result of Deerfield Convertible Note principal and interest conversion 598,568 Common stock options exercised 23,682 Common stock sold under underwritten public offering 8,333,334 Common stock issued as a result of Series A Convertible Preferred Stock conversion 2,080,000 Balance as of December 31, 2018 26,455,352

Note K - Stock-based Compensa_2

Note K - Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	Year Ended December 31, 2018 2017 Research and development $ 1,608 $ 1,304 General and administrative 3,651 3,258 Severance expense 1,236 — Total stock-based compensation expense $ 6,495 $ 4,562
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	December 31, 2018 2017 Risk-free interest rate 2.43% - 2.91% 1.88% - 2.26% Expected term (in years) 5.50 - 6.79 5.12 - 7.00 Expected volatility 83.10% - 85.05% 85.35% - 95.08% Expected dividend yield 0% 0%
Share-based Compensation, Stock Options, Activity [Table Text Block]	Weighted Average Number of Weighted Average Remaining Contractual Aggregate Intrinsic Options Exercise Price Term (in years) Value Outstanding balance as of January 1, 2018 2,853,924 $ 10.50 7.90 $ 471,539 Granted 898,000 $ 5.54 Exercised (23,682 ) $ 3.15 Canceled or forfeited (20,821 ) $ 10.63 Expired (2,666 ) $ 3.00 Outsta nding balance as of December 31, 2018 3,704,755 $ 9.35 7.48 $ — Exercisable as of December 31, 2018 1,837,582 $ 11.56 6.67 $ — Vested and expected to vest as of December 31, 2018 3,656,474 $ 9.40 7.47 $ —
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	Options Outstanding Options Exercisable Weighted Average Weighted Average Number of Remaining Contractual Number of Remaining Contractual Exercise Price Shares Term (in years) Shares Term (in years) $2.75 to $5.00 1,024,995 7.89 390,244 7.59 $5.01 to $10.00 1,256,427 7.85 437,527 5.50 $10.01 to $15.00 471,833 6.94 285,249 6.85 $15.01 to $20.00 603,700 6.89 463,712 6.88 $20.01 to $22.12 347,800 6.68 260,850 6.68 3,704,755 7.48 1,837,582 6.67
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	Number of Unvested Shares December 31, Exercise Price 2018 2017 $2.75 to $5.00 634,751 979,000 $5.01 to $10.00 818,900 21,301 $10.01 to $15.00 186,584 282,542 $15.01 to $20.00 139,988 352,789 $20.01 to $22.12 86,950 173,900 Total number of unvested shares 1,867,173 1,809,532

Note L - Fair Value of Financ_2

Note L - Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	Quoted Prices in Significant Balance as of Active Markets Significant Other Unobservable December 31, for Identical Assets Observable Inputs Inputs 2018 (Level 1) (Level 2) (Level 3) Deerfield Warrant liability $ 1,557 $ — $ — $ 1,557 Embedded Warrant Put Option 154 — — 154 Fundamental change and make-whole interest provisions embedded in 2021 Notes — — — — Deerfield Note Conversion Feature 134 — — 134 KVK Warrant liability 273 — 273 — Total liabilities $ 2,118 $ — $ 273 $ 1,845 Trading securities: Certificates of deposit 246 246 — — U.S. Treasury securities 3,014 3,014 — — Total assets $ 3,260 $ 3,260 $ — $ — Quoted Prices in Significant Balance as of Active Markets Significant Other Unobservable December 31, for Identical Assets Observable Inputs Inputs 2017 (Level 1) (Level 2) (Level 3) Deerfield Warrant liability $ 5,115 $ — $ — $ 5,115 Embedded Warrant Put Option 365 — — 365 Fundamental change and make-whole interest provisions embedded in 2021 Notes 14 — — 14 Deerfield Note Conversion Feature 2,215 2,215 Total liabilities $ 7,709 $ — $ — $ 7,709 Trading securities: Certificates of deposit 5,616 5,616 — — U.S. Treasury securities 25,988 25,988 — — U.S. government-sponsored agency securities 3,004 — 3,004 — Total assets $ 34,608 $ 31,604 $ 3,004 $ —
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	2018 2017 Balance as of beginning of period $ 7,709 $ 4,618 Gain on extinguishment of debt (2 ) — Adjustment to fair value (5,862 ) 3,091 Balance as of end of period $ 1,845 $ 7,709

Note M - Income Taxes (Tables)

Note M - Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Year ended December 31, 2018 2017 Federal statutory rate 21.00 % 34.00 % Effect of: Change in valuation allowance (30.44 ) 13.38 Return to provision and deferred true-up 0.38 2.18 Change in rate 0.03 (49.06 ) State tax benefit (net of federal) 4.35 2.71 Warrant liability 2.02 (2.42 ) State research and development credit 0.22 0.10 Federal research and development credit 3.30 1.50 Amortization — (1.22 ) Stock-based compensation (0.63 ) (1.03 ) Other (0.01 ) (0.04 ) Federal income tax benefit effective rate 0.22 % 0.10 %
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	December 31, 2018 2017 Deferred tax assets relating to: Net operating loss carryforwards $ 51,269 $ 37,028 Research and development tax carryforward 5,657 3,788 Other deferred tax assets 3,437 2,409 Total gross deferred tax assets 60,363 43,225 Deferred tax liabilities relating to: Property and equipment 161 260 Other deferred tax liabilities 10 — Total gross deferred tax liabilities 171 260 Deferred tax assets less liabilities 60,192 42,965 Valuation allowance (60,192 ) (42,965 ) Net deferred tax asset (liability) $ — $ —
Summary of Operating Loss Carryforwards [Table Text Block]	Net Research Operating Loss Activities Year Incurred Carryforwards Credit Expiration 2007 $ 454 $ 30 2027 2008 1,178 65 2028 2009 3,060 176 2029 2010 3,423 149 2030 2011 9,929 176 2031 2012 — 170 2032 2013 4,353 133 2033 2014 15,897 894 2034 2015 23,496 598 2035 2016 41,580 745 2036 2017 34,776 652 2037 2018 56,105 1,869 Indefinite $ 194,251 $ 5,657

Note N - Net Loss Per Share (Ta

Note N - Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Year ended December 31, 2018 2017 Net loss - basic and diluted $ (56,466 ) $ (43,386 ) Weighted average number of shares of common stock - basic and diluted 17,930,023 14,652,898 Net loss per share - basic and diluted $ (3.15 ) $ (2.96 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	December 31, 2018 2017 Deerfield Convertible Note 1,167,607 1,751,410 2021 Notes 4,481,182 5,040,914 Awards under equity incentive plans 3,704,755 2,853,924 Warrants to purchase common stock 2,527,763 2,027,763 Series A Convertible Preferred Stock 1,112,334 — Total securities excluded from the calculation of weighted average number of shares of common stock outstanding 12,993,641 11,674,011

Note A - Description of Busin_2

Note A - Description of Business and Basis of Presentation (Details Textual) - USD ($)	Feb. 28, 2019	Oct. 10, 2018	Oct. 10, 2018	Oct. 05, 2018	Sep. 04, 2018	Sep. 30, 2018	Dec. 31, 2018	Sep. 04, 2018
Sale of Securities, Value, Available to Issue							$ 150,000,000
Sale of Securities, Value, Remaining Available to Issue							120,100,000
Sale of Securities Covered Under Prospectus Supplement, Value, Available to Issue							50,000,000
Sale of Securities Covered Under Prospectus Supplement, Value, Anticipated Amount to Be Sold Under Registration Statement							18,500,000
Sale of Securities Covered Under Prospectus Supplement, Value, Anticipated Sales Under Purchase Agreement							15,300,000
Sale of Securities Covered Under Prospectus Supplement, Value, Anticipated Sales Under ATM Agreement							$ 3,200,000
Second ATM Agreement [Member]
Stock Issued During Period, Shares, New Issues						0
Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues							8,333,334
Cowen and Company, LLC [Member]
Proceeds from Issuance of Common Stock		$ 25,000,000			$ 4,900,000			$ 4,900,000
Stock Issued During Period, Shares, New Issues								762,338
Sale of Stock, Commission Fee					3.00%			3.00%
RBC Capital Markets, LLC [Member]
Sale of Stock, Authorized Offering Price					$ 50,000,000			$ 50,000,000
RBC Capital Markets, LLC [Member] | Second ATM Agreement [Member]
Sale of Stock, Commission Fee					3.00%			3.00%
RBC Capital Markets, LLC [Member] | Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues			8,333,334	8,333,334
Shares Issued, Price Per Share		$ 3	$ 3
Proceeds from Issuance of Common Stock, Net			$ 23,100,000
RBC Capital Markets, LLC [Member] | Maximum [Member] | Second ATM Agreement [Member]
Sale of Stock, Authorized Offering Price					$ 50,000,000			$ 50,000,000
Lincoln Park [Member] | Subsequent Event [Member]
Sale of Securities, Value, Available to Issue	$ 15,000,000
Purchase Agreement, Term	3 years
Purchase Agreement, Additional Shares to Be Issued as Commitment Shares	120,200

Note B - Summary of Significa_2

Note B - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Asset Impairment Charges, Total	$ 0	$ 0
Accounting Standards Update 2016-02 [Member] | Subsequent Event [Member]
Operating Lease, Right-of-Use Asset			$ 3,000
Operating Lease, Liability, Total			$ 3,000
Earliest Tax Year [Member]
Open Tax Year	2,014
Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life	10 years

Note C - Prepaid Expenses and_3

Note C - Prepaid Expenses and Other Current Assets - Components of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Prepaid insurance	$ 224	$ 202
Other receivables	140	76
Other prepaid expenses and current assets	1,688	1,384
Total prepaid expenses and other current assets	$ 2,052	$ 1,662

Note D - Property and Equipme_3

Note D - Property and Equipment (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Depreciation, Depletion and Amortization, Total	$ 324,000	$ 336,000

Note D - Property and Equipme_4

Note D - Property and Equipment - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property and equipment, gross	$ 3,006	$ 2,933
Less: accumulated depreciation and amortization	(1,253)	(929)
Property and equipment, net	1,753	2,004
Laboratory Equipment [Member]
Property and equipment, gross	1,035	983
Furniture and Fixtures [Member]
Property and equipment, gross	655	655
Computer and Hardware [Member]
Property and equipment, gross	299	292
Leasehold Improvements [Member]
Property and equipment, gross	$ 1,017	$ 1,003

Note D - Property and Equipme_5

Note D - Property and Equipment - Assets Under Capital Leases Included in Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Capital leased assets, gross	$ 1,018	$ 966
Less: accumulated depreciation and amortization	(272)	(150)
Property and equipment financed under a capital lease agreement, net	746	816
Laboratory Equipment [Member]
Capital leased assets, gross	418	366
Furniture and Fixtures [Member]
Capital leased assets, gross	541	541
Leasehold Improvements [Member]
Capital leased assets, gross	$ 59	$ 59

Note D - Property and Equipme_6

Note D - Property and Equipment - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2018
Minimum [Member]
Property and equipment, useful lives (Year)	3 years
Maximum [Member]
Property and equipment, useful lives (Year)	10 years
Laboratory Equipment [Member]
Property and equipment, useful lives (Year)	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Property and equipment, useful lives (Year)	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Property and equipment, useful lives (Year)	10 years
Computer and Hardware [Member] | Minimum [Member]
Property and equipment, useful lives (Year)	3 years
Computer and Hardware [Member] | Maximum [Member]
Property and equipment, useful lives (Year)	7 years
Leasehold Improvements [Member]
Property and equipment, useful lives (Year)	9 years

Note E - Accounts Payable and_3

Note E - Accounts Payable and Accrued Expenses - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued interest	$ 1,921	$ 2,222
Accrued banking fees	700	700
Accrued severance	193
Accrued payroll	731	1,118
Accounts payable	3,715	2,177
Other accrued expenses	1,082	1,658
Total accounts payable and accrued expenses	$ 8,342	$ 7,875

Note F - Debt Obligations (Deta

Note F - Debt Obligations (Details Textual) - USD ($)	Oct. 05, 2018	Jun. 11, 2018	Feb. 09, 2016	Jun. 02, 2014	Dec. 31, 2018	Dec. 31, 2017	Nov. 20, 2018	Jun. 30, 2016	Dec. 31, 2013
Interest Paid, Excluding Capitalized Interest, Operating Activities					$ 5,593,000	$ 5,717,000
Deerfield Warrant [Member]
Beneficial Ownership, Cap Limit, Percentage							4.985%
Conversion from Deerfield Convertible Note to Common Stock [Member]
Debt Conversion, Converted Instrument, Shares Issued		598,568
Debt Conversion, Original Debt, Amount		$ 3,333,333
Debt Conversion, Accrued Interest		$ 168,288
Exchanged 2021 Notes for Series A Preferred Stock [Member]
Debt Conversion, Converted Instrument, Shares Issued	9,577
Debt Conversion, Original Debt, Amount	$ 9,577,000				9,577,000
Interest Paid, Excluding Capitalized Interest, Operating Activities	95,105
Debt Conversion, Expenses, Reimbursement	$ 25,000
Preferred Stock, Aggregate Stated Value Per Share	$ 1,000
Convertible Notes 2021 [Member]
Beneficial Ownership, Cap Limit, Percentage							9.985%
Deerfield Convertible Notes [Member]
Beneficial Ownership, Cap Limit, Percentage							4.985%
Series D Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights									1,079,453
Series A Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	0.0001		$ 0.0001
Preferred Stock, Aggregate Stated Value Per Share	1,000
Convertible Preferred Stock, Conversion Price	$ 3
Convertible Preferred Stock, Shares Issuable Upon Conversion	3,192,334
Convertible Preferred Stock, Conversion Restriction, Percentage of Common Stock	4.985%
2021 Notes [Member]
Debt Instrument, Convertible, Conversion Price			$ 17.11
Debt Instrument, Face Amount			$ 86,300,000
Debt Instrument, Interest Rate, Stated Percentage			5.50%
Proceeds from Debt, Net of Issuance Costs			$ 82,800,000
Repayments of Long-term Debt, Total			18,600,000
Debt Instrument, Sinking Fund Payment			$ 0
Debt Conversion, Converted Instrument, Shares Issued			58.4454
Debt Conversion, Original Debt, Amount			$ 1,000
Debt Instrument Repurchase Price Equal to Percentage of Principal Amount			100.00%
Deerfield Facility Agreement [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 60,000,000
Line of Credit Facility, Interest Rate at Period End				9.75%
Debt Covenant, Debt Financing Restriction				$ 750,000
Deerfield Facility Agreement [Member] | IPO [Member]
Reclassification of Common Stock Shares				256,410
Deerfield Facility Agreement [Member] | Deerfield Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 0.78
Deerfield Facility Agreement [Member] | Deerfield Warrant [Member] | IPO [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				1,923,077
Deerfield Facility Agreement [Member] | Series D Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				14,423,076
Own-share Lending Arrangement, Shares, Issued				1,923,077
Mandatorily Redeemable Preferred Stock, Fair Value Disclosure				$ 1,500,000
Deerfield Facility Agreement [Member] | Term Notes [Member]
Proceeds from Secured Notes Payable				15,000,000
Deerfield Facility Agreement [Member] | Deerfield Convertible Notes [Member]
Proceeds from Secured Notes Payable				$ 10,000,000
Debt Instrument, Convertible, Conversion Price				$ 5.85
Third Line of Credit Agreement [Member] | City National Bank of Florida [Member]
Line of Credit Facility, Maximum Borrowing Capacity								$ 1,100,000
Line of Credit Facility, Remaining Borrowing Capacity					400,000	400,000
Long-term Line of Credit, Total					$ 0	$ 0
Third Line of Credit Agreement [Member] | City National Bank of Florida [Member] | Prime Rate [Member]
Debt Instrument, Interest Rate, Stated Percentage					4.35%
Debt Instrument, Basis Spread on Variable Rate					2.00%

Note F - Debt Obligations - Fut

Note F - Debt Obligations - Future Minimum Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
2,019	$ 3,333
2,020	3,334
2,021	76,673
Total minimum principal payments	83,340
Less: debt issuance costs and discount	(1,902)
Convertible notes, net	$ 81,438

Note G - Commitments and Cont_3

Note G - Commitments and Contingencies (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Loss Contingency Accrual, Ending Balance	$ 0	$ 0
Operating and Capital Leases, Rent Expense, Net	$ 700	$ 600
Capital Lease One [Member]
Capital Lease, Interest Rate	7.19%
Capital Lease Two [Member]
Capital Lease, Interest Rate		9.57%
FLORIDA
Number of Units Leased	2
Lessee Leasing Arrangements, Operating Leases, Number of Lease Renewals	2
Lessee, Operating Lease, Renewal Term	5 years
IOWA
Lessee, Operating Lease, Renewal Term	1 year
North Carolina 1 [Member]
Lessee, Operating Lease, Renewal Term	3 years

Note G - Commitments and Cont_4

Note G - Commitments and Contingencies - Future Minimum Lease Payments Under Capital Leases and Non-cancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
2,019	$ 254
2,019	714
2,020	251
2,020	499
2,021	163
2,021	449
2,022	11
2,022	461
2,023
2,023	472
Thereafter
Thereafter	903
Total minimum lease payments	679
Total minimum lease payments	3,498
Less: amounts representing interest	(69)
Total minimum capital lease principal payments	$ 610

Note H - Supply Arrangement (De

Note H - Supply Arrangement (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Number of Manufacturing Arrangements	1	1
Supply Arrangement Expense	$ 3,600	$ 0
Supply Arrangement, Automatic Renewal Period	2 years
Supply Arrangement, Period of Prior Notice	1 year

Note I - Preferred Stock and _2

Note I - Preferred Stock and Warrants (Details Textual) - USD ($) $ / shares in Units, $ in Millions	Feb. 28, 2019	Oct. 05, 2018	Jun. 02, 2014	Dec. 31, 2013	Dec. 31, 2018	Dec. 31, 2017	Feb. 09, 2016
Preferred Stock, Shares Authorized					10,000,000	10,000,000
Preferred Stock, Shares Issued, Total					9,577
Preferred Stock, Shares Outstanding, Ending Balance					3,337
Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				143,466
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 5.85
2013 Warrants [Member]
Class of Warrant or Right Issued				1,079,453
Deerfield Warrant [Member]
Class of Warrant or Right Issued			14,423,076
Deerfield Warrant [Member] | Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			1,923,077
Class of Warrant or Right, Exercise Price of Warrants or Rights			$ 5.85
Convertible Notes Payable [Member]
Debt Instrument, Face Amount				$ 3.8
Exchanged 2021 Notes for Series A Preferred Stock [Member]
Debt Conversion, Converted Instrument, Shares Issued		9,577
Preferred Stock, Aggregate Stated Value Per Share		$ 1,000
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized					9,578
Preferred Stock, Aggregate Stated Value Per Share		1,000
Convertible Preferred Stock, Conversion Price		$ 3
Convertible Preferred Stock, Shares Issuable Upon Conversion		3,192,334
Convertible Preferred Stock, Conversion Restriction, Percentage of Common Stock		4.985%
Preferred Stock, Par or Stated Value Per Share		$ 0.0001					$ 0.0001
Series A Preferred Stock [Member] | Subsequent Event [Member]
Preferred Stock, Shares Outstanding, Ending Balance	3,337
Convertible Preferred Stock, Shares Issuable Upon Conversion	1,112,334
Conversion of Stock, Shares Converted	6,240
Conversion of Stock, Shares Issued	2,080,000
Series D Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				1,079,453

Note J - Common Stock and War_3

Note J - Common Stock and Warrants (Details Textual) - USD ($)	Feb. 28, 2019	Oct. 25, 2018	Oct. 10, 2018	Oct. 10, 2018	Oct. 05, 2018	Sep. 04, 2018	Dec. 31, 2018	Dec. 31, 2017	Sep. 04, 2018	Dec. 31, 2016	Dec. 31, 2012
Common Stock, Shares Authorized							250,000,000	250,000,000
Common Stock, Shares, Issued, Total							26,455,352	14,657,430
Common Stock Issued During Period from Warrants Exercised								698
Class of Warrant or Right Exercised							0
Common Stock, Shares, Outstanding, Ending Balance							26,455,352	14,657,430		14,646,982
Warrant Issued to KVK [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		500,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 2.30
Class of Warrant or Right, Additional Shares Exercisable for Each Milestones		125,000
Series A Preferred Stock Converted Into Common Stock [Member]
Conversion of Stock, Shares Converted	6,240
Conversion of Stock, Shares Issued	2,080,000						2,080,000
Exchanged 2021 Notes for Series A Preferred Stock [Member]
Debt Conversion, Converted Instrument, Shares Issued					9,577
Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues							8,333,334
Private Placement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights											595,920
Cowen and Company, LLC [Member]
Stock Issued During Period, Shares, New Issues									762,338
Proceeds from Issuance of Common Stock			$ 25,000,000			$ 4,900,000			$ 4,900,000
RBC Capital Markets, LLC [Member] | Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues				8,333,334	8,333,334

Note J - Common Stock and War_4

Note J - Common Stock and Warrants - Reserved Authorized Shares of Common Stock for Future Issuance (Details) - shares	Dec. 31, 2018	Dec. 31, 2017
Common shares reserved for future issuance (in shares)	13,641,913	12,618,711
Series A Convertible Preferred Stock [Member]
Common shares reserved for future issuance (in shares)	1,112,334
Warrant [Member]
Common shares reserved for future issuance (in shares)	2,527,763	2,027,763
Stock Compensation Plan [Member]
Common shares reserved for future issuance (in shares)	3,704,755	2,853,924
Possible Future Issuances Under Equity Incentive Plans [Member]
Common shares reserved for future issuance (in shares)	648,272	944,700
2021 Notes [Member]
Common shares reserved for future issuance (in shares)	4,481,182	5,040,914
Convertible Notes Payable [Member]
Common shares reserved for future issuance (in shares)	1,167,607	1,751,410

Note J - Common Stock and War_5

Note J - Common Stock and Warrants - Common Stock Activity (Details) - shares	Feb. 28, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance (in shares)		14,657,430	14,646,982
Common stock warrants exercised (in shares)			698
Common stock options exercised (in shares)		23,682	9,750
Common stock issued as a result of Deerfield Convertible Note principal and interest conversion (in shares)		598,568
Balance (in shares)		26,455,352	14,657,430
Series A Preferred Stock Converted Into Common Stock [Member]
Common stock issued as a result of Series A Convertible Preferred Stock conversion (in shares)	2,080,000	2,080,000
First ATM Agreement [Member]
Common stock sold under First ATM Agreement (in shares)		762,338
Underwriting Agreement [Member]
Common stock sold under First ATM Agreement (in shares)		8,333,334

Note K - Stock-based Compensa_3

Note K - Stock-based Compensation (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Increase in Common Stock Reserved for Issuance	1,058,214
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	23,682	9,750
Stock Issued During Period, Value, Stock Options Exercised	$ 68,000	$ 7,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 69,000	$ 32,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value	$ 4.05	$ 2.77
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 5,900,000	$ 4,100,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total	$ 6,000,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 306 days
Allocated Share-based Compensation Expense, Total	$ 6,495,000	4,562,000
Performance Shares [Member]
Allocated Share-based Compensation Expense, Total	$ 0	$ 0
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,018,480
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Reserved for Issuance, Incremental Percentage of Capital Stock Outstanding	4.00%

Note K - Stock-based Compensa_4

Note K - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Stock based compensation expense	$ 6,495	$ 4,562
Research and Development Expense [Member]
Stock based compensation expense	1,608	1,304
General and Administrative Expense [Member]
Stock based compensation expense	3,651	3,258
Severance Expense [Member]
Stock based compensation expense	$ 1,236

Note K - Stock-based Compensa_5

Note K - Stock-based Compensation - Black-Scholes Option-pricing Model (Details)	12 Months Ended
	Dec. 31, 2017
Expected dividend yield	0.00%
Minimum [Member]
Expected dividend yield	0.00%

Note K - Stock-based Compensa_6

Note K - Stock-based Compensation - Schedule of Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Outstanding, number of options (in shares)	2,853,924
Outstanding, weighted average exercise price (in dollars per share)	$ 10.50
Outstanding, weighted average remaining contractual term (Year)	7 years 175 days	7 years 328 days
Outstanding, aggregate intrinsic value	$ 471,539
Granted, number of options (in shares)	898,000
Granted, weighted average exercise price (in dollars per share)	$ 5.54
Exercised, number of options (in shares)	(23,682)	(9,750)
Exercised, weighted average exercise price (in dollars per share)	$ 3.15
Canceled or forfeited, number of options (in shares)	(20,821)
Canceled or forfeited, weighted average exercise price (in dollars per share)	$ 10.63
Expired, number of options (in shares)	(2,666)
Expired, weighted average exercise price (in dollars per share)	$ 3
Outstanding, number of options (in shares)	3,704,755	2,853,924
Outstanding, weighted average exercise price (in dollars per share)	$ 9.35	$ 10.50
Exercisable, number of options (in shares)	1,837,582
Exercisable, weighted average exercise price (in dollars per share)	$ 11.56
Exercisable, weighted average remaining contractual term (Year)	6 years 244 days
Vested and expected to vest, number of options (in shares)	3,656,474
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 9.40
Vested and expected to vest, weighted average remaining contractual term (Year)	7 years 171 days

Note K - Stock-based Compensa_7

Note K - Stock-based Compensation - Information Regarding Currently Outstanding and Exercisable Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Options outstanding, number of shares (in shares)	3,704,755	2,853,924
Outstanding, weighted average remaining contractual term (Year)	7 years 175 days	7 years 328 days
Exercisable, number of options (in shares)	1,837,582
Exercisable, weighted average remaining contractual term (Year)	6 years 244 days
Exercise Price Range One [Member]
Lower range (in dollars per share)	$ 2.75
Upper range (in dollars per share)	$ 5
Options outstanding, number of shares (in shares)	1,024,995
Outstanding, weighted average remaining contractual term (Year)	7 years 324 days
Exercisable, number of options (in shares)	390,244
Exercisable, weighted average remaining contractual term (Year)	7 years 215 days
Exercise Price Range Two [Member]
Lower range (in dollars per share)	$ 5.01
Upper range (in dollars per share)	$ 10
Options outstanding, number of shares (in shares)	1,256,427
Outstanding, weighted average remaining contractual term (Year)	7 years 310 days
Exercisable, number of options (in shares)	437,527
Exercisable, weighted average remaining contractual term (Year)	5 years 182 days
Exercise Price Range Three [Member]
Lower range (in dollars per share)	$ 10.01
Upper range (in dollars per share)	$ 15
Options outstanding, number of shares (in shares)	471,833
Outstanding, weighted average remaining contractual term (Year)	6 years 343 days
Exercisable, number of options (in shares)	285,249
Exercisable, weighted average remaining contractual term (Year)	6 years 310 days
Exercise Price Range Four [Member]
Lower range (in dollars per share)	$ 15.01
Upper range (in dollars per share)	$ 20
Options outstanding, number of shares (in shares)	603,700
Outstanding, weighted average remaining contractual term (Year)	6 years 324 days
Exercisable, number of options (in shares)	463,712
Exercisable, weighted average remaining contractual term (Year)	6 years 321 days
Exercise Price Range Five [Member]
Lower range (in dollars per share)	$ 20.01
Upper range (in dollars per share)	$ 22.12
Options outstanding, number of shares (in shares)	347,800
Outstanding, weighted average remaining contractual term (Year)	6 years 248 days
Exercisable, number of options (in shares)	260,850
Exercisable, weighted average remaining contractual term (Year)	6 years 248 days

Note K - Stock-based Compensa_8

Note K - Stock-based Compensation - Nonvested Stock Option Awards (Details) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Number of unvested shares (in shares)	1,867,173	1,809,532
Exercise Price Range One [Member]
Number of unvested shares (in shares)	634,751	979,000
Exercise Price Range One [Member] | Minimum [Member]
Exercise price (in dollars per share)	$ 2.75
Exercise Price Range One [Member] | Maximum [Member]
Exercise price (in dollars per share)	$ 5
Exercise Price Range Two [Member]
Number of unvested shares (in shares)	818,900	21,301
Exercise Price Range Two [Member] | Minimum [Member]
Exercise price (in dollars per share)	$ 5.01
Exercise Price Range Two [Member] | Maximum [Member]
Exercise price (in dollars per share)	$ 10
Exercise Price Range Three [Member]
Number of unvested shares (in shares)	186,584	282,542
Exercise Price Range Three [Member] | Minimum [Member]
Exercise price (in dollars per share)	$ 10.01
Exercise Price Range Three [Member] | Maximum [Member]
Exercise price (in dollars per share)	$ 15
Exercise Price Range Four [Member]
Number of unvested shares (in shares)	139,988	352,789
Exercise Price Range Four [Member] | Minimum [Member]
Exercise price (in dollars per share)	$ 15.01
Exercise Price Range Four [Member] | Maximum [Member]
Exercise price (in dollars per share)	$ 20
Exercise Price Range Five [Member]
Number of unvested shares (in shares)	86,950	173,900
Exercise Price Range Five [Member] | Minimum [Member]
Exercise price (in dollars per share)	$ 20.01
Exercise Price Range Five [Member] | Maximum [Member]
Exercise price (in dollars per share)	$ 22.12

Note L - Fair Value of Financ_3

Note L - Fair Value of Financial Instruments (Details Textual) - Fair Value, Inputs, Level 3 [Member] - Deerfield Facility Agreement [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deerfield Convertible Notes [Member]
Long-term Debt, Fair Value	$ 6.2	$ 11
Term Notes [Member]
Long-term Debt, Fair Value	$ 51.2	$ 51.9

Note L - Fair Value of Financ_4

Note L - Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial liabilities measured at fair value on recurring basis	$ 2,118	$ 7,709
Financial assets measured at fair value on recurring basis	3,260	34,608
Certificates of Deposit [Member]
Financial assets measured at fair value on recurring basis	246	5,616
US Treasury Securities [Member]
Financial assets measured at fair value on recurring basis	3,014	25,988
US Government Corporations and Agencies Securities [Member]
Financial assets measured at fair value on recurring basis		3,004
Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis
Financial assets measured at fair value on recurring basis	3,260	31,604
Fair Value, Inputs, Level 1 [Member] | Certificates of Deposit [Member]
Financial assets measured at fair value on recurring basis	246	5,616
Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Financial assets measured at fair value on recurring basis	3,014	25,988
Fair Value, Inputs, Level 1 [Member] | US Government Corporations and Agencies Securities [Member]
Financial assets measured at fair value on recurring basis
Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis	273
Financial assets measured at fair value on recurring basis		3,004
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]
Financial assets measured at fair value on recurring basis
Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Financial assets measured at fair value on recurring basis
Fair Value, Inputs, Level 2 [Member] | US Government Corporations and Agencies Securities [Member]
Financial assets measured at fair value on recurring basis		3,004
Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	1,845	7,709
Financial assets measured at fair value on recurring basis
Fair Value, Inputs, Level 3 [Member] | Certificates of Deposit [Member]
Financial assets measured at fair value on recurring basis
Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Financial assets measured at fair value on recurring basis
Fair Value, Inputs, Level 3 [Member] | US Government Corporations and Agencies Securities [Member]
Financial assets measured at fair value on recurring basis
Deerfield Warrant Liability [Member]
Financial liabilities measured at fair value on recurring basis	1,557	5,115
Deerfield Warrant Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis
Deerfield Warrant Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis
Deerfield Warrant Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	1,557	5,115
Embedded Put Option [Member]
Financial liabilities measured at fair value on recurring basis	154	365
Embedded Put Option [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis
Embedded Put Option [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis
Embedded Put Option [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	154	365
Fundamental Change and Make-Whole Interest Provisions Embedded in 2021 Notes [Member]
Financial liabilities measured at fair value on recurring basis		14
Fundamental Change and Make-Whole Interest Provisions Embedded in 2021 Notes [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis
Fundamental Change and Make-Whole Interest Provisions Embedded in 2021 Notes [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis
Fundamental Change and Make-Whole Interest Provisions Embedded in 2021 Notes [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis		14
Embedded Deerfield Note Put Option [Member]
Financial liabilities measured at fair value on recurring basis	134	2,215
Embedded Deerfield Note Put Option [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis
Embedded Deerfield Note Put Option [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis
Embedded Deerfield Note Put Option [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	134	$ 2,215
KVK Warrant Liability [Member]
Financial liabilities measured at fair value on recurring basis	273
KVK Warrant Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis
KVK Warrant Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis	273
KVK Warrant Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis

Note L - Fair Value of Financ_5

Note L - Fair Value of Financial Instruments - Reconciliation of Beginning and Ending Balances for Derivative and Warrant Liability Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Balance as of beginning of period	$ 7,709	$ 4,618
Gain on extinguishment of debt	(2)
Adjustment to fair value	(5,862)	3,091
Balance as of end of period	$ 1,845	$ 7,709

Note M - Income Taxes (Details

Note M - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
State and Local Income Tax Expense (Benefit), Continuing Operations, Total	$ (126,000)	$ (43,000)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(56,592,000)	$ (43,429,000)
Operating Loss Carryforwards, Total	194,251,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	$ 136,000,000
Operating Loss Carryforwards, Expiration, Beginning Year	2,027
Operating Loss Carryforwards, Expiration, Ending Year	2,037

Note M - Income Taxes - Schedul

Note M - Income Taxes - Schedule of Reconciliation of Difference Between Benefit for Income Taxes and Income Taxes at Statutory U.S. Federal Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Federal statutory rate	21.00%	34.00%
Change in valuation allowance	(30.44%)	13.38%
Return to provision and deferred true-up	0.38%	2.18%
Change in rate	0.03%	(49.06%)
State tax benefit (net of federal)	4.35%	2.71%
Warrant liability	2.02%	(2.42%)
State research and development credit	0.22%	0.10%
Federal research and development credit	3.30%	1.50%
Amortization		(1.22%)
Stock-based compensation	(0.63%)	(1.03%)
Other	(0.01%)	(0.04%)
Federal income tax benefit effective rate	0.22%	0.10%

Note M - Income Taxes - Compone

Note M - Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Net operating loss carryforwards	$ 51,269	$ 37,028
Research and development tax carryforward	5,657	3,788
Other deferred tax assets	3,437	2,409
Total gross deferred tax assets	60,363	43,225
Property and equipment	161	260
Other deferred tax liabilities	10
Total gross deferred tax liabilities	171	260
Deferred tax assets less liabilities	60,192	42,965
Valuation allowance	(60,192)	(42,965)
Net deferred tax asset (liability)

Note M - Income Taxes - Federal

Note M - Income Taxes - Federal Net Operating Loss Carryforward and Research Activities Credit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Net Operating Loss Carryforwards	$ 194,251
Research Activities Tax Credit	5,657	$ 3,788
Tax Year 2007 [Member]
Net Operating Loss Carryforwards	454
Research Activities Tax Credit	$ 30
Expiration	2,027
Tax Year 2008 [Member]
Net Operating Loss Carryforwards	$ 1,178
Research Activities Tax Credit	$ 65
Expiration	2,028
Tax Year 2009 [Member]
Net Operating Loss Carryforwards	$ 3,060
Research Activities Tax Credit	$ 176
Expiration	2,029
Tax Year 2010 [Member]
Net Operating Loss Carryforwards	$ 3,423
Research Activities Tax Credit	$ 149
Expiration	2,030
Tax Year 2011 [Member]
Net Operating Loss Carryforwards	$ 9,929
Research Activities Tax Credit	$ 176
Expiration	2,031
Tax Year 2012 [Member]
Net Operating Loss Carryforwards
Research Activities Tax Credit	$ 170
Expiration	2,032
Tax Year 2013 [Member]
Net Operating Loss Carryforwards	$ 4,353
Research Activities Tax Credit	$ 133
Expiration	2,033
Tax Year 2014 [Member]
Net Operating Loss Carryforwards	$ 15,897
Research Activities Tax Credit	$ 894
Expiration	2,034
Tax Year 2015 [Member]
Net Operating Loss Carryforwards	$ 23,496
Research Activities Tax Credit	$ 598
Expiration	2,035
Tax Year 2016 [Member]
Net Operating Loss Carryforwards	$ 41,580
Research Activities Tax Credit	$ 745
Expiration	2,036
Tax Year 2017 [Member]
Net Operating Loss Carryforwards	$ 34,776
Research Activities Tax Credit	$ 652
Expiration	2,037
Tax Year 2018 [Member]
Net Operating Loss Carryforwards	$ 56,105
Research Activities Tax Credit	$ 1,869

Note N - Net Loss Per Share - S

Note N - Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss and Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Net loss - basic and diluted	$ (56,466)	$ (43,386)
Weighted average number of shares of common stock - basic and diluted (in shares)	17,930,023	14,652,898
Net loss per share - basic and diluted (in dollars per share)	$ (3.15)	$ (2.96)

Note N - Net Earnings Per Share

Note N - Net Earnings Per Share - Anti-dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Antidilutive securities (in shares)	12,993,641	11,674,011
Convertible Debt Securities [Member]
Antidilutive securities (in shares)	1,167,607	1,751,410
2021 Notes [Member]
Antidilutive securities (in shares)	4,481,182	5,040,914
Stock Compensation Plan [Member]
Antidilutive securities (in shares)	3,704,755	2,853,924
Warrants to Purchase Common Stock [Member]
Antidilutive securities (in shares)	2,527,763	2,027,763
Series A Convertible Preferred Stock [Member]
Antidilutive securities (in shares)	1,112,334

Note O - Severance Expense (Det

Note O - Severance Expense (Details Textual) - USD ($) $ in Thousands	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Allocated Share-based Compensation Expense, Total		$ 6,495	$ 4,562
Severance Expense [Member]
Allocated Share-based Compensation Expense, Total		1,236
Employee Severance [Member] | Accounts Payable and Accrued Liabilities [Member]
Accrued Severance Expense		$ 200
Employee Severance [Member] | Severance Expense [Member]
Severance Charges	$ 400
Allocated Share-based Compensation Expense, Total	$ 1,200

Note P - Employee Benefit Plan

Note P - Employee Benefit Plan (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Retirement Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 212,000	$ 207,000
Profit Sharing Plan [Member]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 0	$ 0
Defined Contribution Plan, Requisite Service Period	3 years