Vaxart (VXRT) 10-Q 13 Nov 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 12, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Vaxart, Inc.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		7,141,189
Amendment Flag	false
Entity Central Index Key	72,444
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Ex Transition Period	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 17,922	$ 1,571
Short-term investments		1,415
Accounts receivable, net of allowance	256	630
Prepaid expenses and other current assets	989	137
Total current assets	19,167	3,753
Property and equipment, net	1,059	730
Intangible assets, net	20,410	40
Total assets	40,636	4,523
Current liabilities:
Accounts payable	1,301	1,390
Current portion of secured promissory note payable to Oxford Finance	1,667	1,528
Short-term note payable	102
Liability related to sale of future royalties, current portion	3,279
Other accrued liabilities	1,677	1,605
Total current liabilities	8,026	4,523
Convertible promissory notes, long-term, related parties		35,282
Liability related to sale of future royalties, net of current portion	14,301
Secured promissory note payable to Oxford Finance, net of current portion	2,321	3,440
Total liabilities	24,648	43,245
Commitments and contingencies (Note 10)
Stockholders’ equity (deficit):
Preferred Stock: $0.10 par value; 5,000,000 shares authorized; none issued and outstanding as of September 30, 2018; 1,221,064 issued and outstanding as of December 31, 2017, with aggregate liquidation value of $39,956		1
Common Stock: $0.10 par value; 200,000,000 shares authorized; 7,141,189 and 138,492 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	714
Additional paid-in capital	108,361	41,259
Accumulated deficit	(93,087)	(79,982)
Total stockholders’ equity (deficit)	15,988	(38,722)
Total liabilities and stockholders’ equity (deficit)	$ 40,636	$ 4,523

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Preferred stock, par value (in Dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	1,221,064
Preferred stock, shares outstanding	0	1,221,064
Liquidation Preference (in Dollars)	$ 39,956	$ 39,956
Common stock, par value (in Dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	7,141,189	138,492
Common stock, shares outstanding	7,141,189	138,492

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Revenue	$ 281,000	$ 915,000	$ 2,392,000	$ 5,079,000
Operating expenses:
Research and development	4,381,000	2,247,000	12,801,000	10,450,000
General and administrative	1,674,000	624,000	5,455,000	1,955,000
Impairment of intangible assets			1,600,000
Impairment of property and equipment	106,000		106,000
Total operating expenses	6,161,000	2,871,000	19,962,000	12,405,000
Operating loss	(5,880,000)	(1,956,000)	(17,570,000)	(7,326,000)
Other income and (expenses):
Bargain purchase gain			6,660,000
Interest income	11,000	18,000	52,000	51,000
Interest expense	(129,000)	(768,000)	(702,000)	(2,267,000)
Non-cash interest expense related to sale of future royalties	(532,000)		(1,298,000)
Gain on sale of equipment		69,000		69,000
Gain (loss) on revaluation of financial instruments, net		464,000	(3,000)	966,000
Foreign exchange loss	(18,000)		(215,000)
Total other income and (expenses)	(668,000)	(217,000)	4,494,000	(1,181,000)
Net loss before provision for income taxes	(6,548,000)	(2,173,000)	(13,076,000)	(8,507,000)
Provision for income taxes			29,000
Net loss	(6,548,000)	(2,173,000)	(13,105,000)	(8,507,000)
Series B and C preferred dividend		(725,000)	(339,000)	(2,153,000)
Net comprehensive loss attributable to common stockholders	$ (6,548,000)	$ (2,898,000)	$ (13,444,000)	$ (10,660,000)
Net loss per share – basic and diluted (in Dollars per share)	$ (0.92)	$ (21.36)	$ (2.23)	$ (78.58)
Shares used to compute net loss per share – basic and diluted (in Shares)	7,141,189	135,658	6,038,001	135,658
Government Contract [Member]
Revenue:
Revenue	$ 194,000	$ 915,000	$ 1,324,000	$ 5,079,000
Royalty [Member]
Revenue:
Revenue	87,000		1,050,000
Non Cash Royalty Revenue [Member]
Revenue:
Revenue			$ 18,000

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Stockholders` Equity (Deficit) (Unaudited) - 9 months ended Sep. 30, 2018 - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balances at Dec. 31, 2017	$ 1		$ 41,259	$ (79,982)	$ (38,722)
Balances (in Shares) at Dec. 31, 2017	1,221,064	138,492			138,492
Issuance of common stock upon conversion of convertible promissory notes, related parties		$ 157	35,420		$ 35,577
Issuance of common stock upon conversion of convertible promissory notes, related parties (in Shares)		1,571,702
Issuance of common stock upon conversion of convertible preferred stock	$ (1)	$ 192	(191)
Issuance of common stock upon conversion of convertible preferred stock (in Shares)	(1,221,064)	1,918,543
Reclassification of warrant to equity			70		70
Issuance of common stock upon reverse merger		$ 365	31,403		31,768
Issuance of common stock upon reverse merger (in Shares)		3,510,439
Issuance of common stock upon exercise of stock options			13		$ 13
Issuance of common stock upon exercise of stock options (in Shares)		2,013			2,013
Stock-based compensation			387		$ 387
Net loss				(13,105)	(13,105)
Balances at Sep. 30, 2018		$ 714	$ 108,361	$ (93,087)	$ 15,988
Balances (in Shares) at Sep. 30, 2018		7,141,189			7,141,189

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (13,105,000)	$ (8,507,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Bargain purchase gain	(6,660,000)
Depreciation and amortization	2,379,000	295,000
Gain on sale of equipment		(69,000)
Impairment of intangible assets	1,600,000
Impairment of property and equipment	106,000
Stock-based compensation	387,000	374,000
Amortization of discount on short-term investments		20,000
Loss (gain) on revaluation of financial instruments, net	3,000	(966,000)
Non-cash interest expense	408,000	1,918,000
Amortization of note discount	18,000	107,000
Non-cash interest expense related to sale of future royalties	1,298,000
Non-cash revenue related to sale of future royalties	(18,000)
Change in operating assets and liabilities:
Accounts receivable, net of allowance	15,040,000	1,263,000
Prepaid expenses and other assets	(416,000)	(133,000)
Accounts payable	(3,495,000)	(2,160,000)
Accrued liabilities	(6,391,000)	67,000
Net cash used in operating activities	(8,846,000)	(7,791,000)
Cash flows from investing activities:
Purchase of property and equipment	(512,000)	(76,000)
Proceeds from sale of equipment		70,000
Cash acquired in reverse merger	25,525,000
Cash paid for fractional shares in merger	(21,000)
Purchases of short-term investments	(573,000)	(6,771,000)
Proceeds from maturities of short-term investments	1,988,000	8,081,000
Net cash provided by investing activities	26,407,000	1,304,000
Cash flows from financing activities:
Repayment of principal on secured promissory note payable to Oxford Finance	(1,111,000)
Repayment of short-term note	(112,000)
Proceeds from issuance of common stock upon exercise of stock options	13,000
Net cash used in financing activities	(1,210,000)
Net increase (decrease) in cash and cash equivalents	16,351,000	(6,487,000)
Cash and cash equivalents at beginning of the period	1,571,000	8,405,000
Cash and cash equivalents at end of the period	17,922,000	1,918,000
Supplemental disclosure of cash flow information:
Interest paid	276,000	241,000
Supplemental disclosure of non-cash financing activity:
Issuance of common stock upon reverse merger, net of cash paid for partial shares	31,768,000
Conversion of convertible promissory notes, related parties into common stock upon reverse merger	35,577,000
Reclassification of convertible preferred stock warrant liability to equity	70,000
Acquisition of property and equipment included in accounts payable	$ 102,000

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	NOTE 1. Organization and Basis of Presentation General Vaxart Biosciences, Inc. was originally incorporated in California in March 2004, under the name West Coast Biologicals, Inc. The Company changed its name to Vaxart, Inc. (“Private Vaxart”) in July 2007, and reincorporated in the state of Delaware. On February 13, 2018, Private Vaxart completed a business combination Aviragen Therapeutics, Inc. (“Aviragen”) pursuant to which Aviragen merged with Private Vaxart, with Private Vaxart surviving as a wholly-owned subsidiary of Aviragen (the “Merger”). Pursuant to the terms of the Merger, Aviragen changed its name to Vaxart, Inc. (together with its subsidiaries, the “Company” or “Vaxart”) and Private Vaxart changed its name to Vaxart Biosciences, Inc Conversion I mmediately following the completion of the Merger, the Company effected a reverse stock split at a ratio of one new share for every eleven shares of the Company’s common stock outstanding Reverse Stock Split Immediately after the Reverse Stock Split there were approximately 7.1 million shares of the Company’s common stock outstanding. Private Vaxart’s stockholders, warrantholders and optionholders owned approximately 51% of the fully-diluted common stock of the Company, with Aviragen’s stockholders and optionholders immediately prior to the Merger owning approximately 49% of the fully-diluted common stock of the Company . The Company also assumed all of Private Vaxart’s outstanding stock options and warrants with proportionate adjustments to the number of underlying shares and exercise prices based on an exchange ratio, based on the combined impact of the Conversion and the Reverse Stock Split, of approximately 0.0201346 shares of the Company for each share of Private Vaxart. The Company’s principal operations are based in South San Francisco, California, and it operates in one reportable segment, which is the discovery and development of oral recombinant protein vaccines, based on its proprietary oral vaccine platform. Liquidity and Going Concern Since incorporation, the Company has been involved primarily in performing research and development activities, hiring personnel, and raising capital to support these activities. The Company has experienced losses and negative cash flows from operations since its inception. As of September 30, 2018, the Company had an accumulated deficit of $93.1 million and a loan with an outstanding balance of $4.0 million from Oxford Finance, LLC (“Oxford Finance”), repayable in monthly installments by January 2021 (see Note 9). The Company expects to incur increasing costs as research and clinical trials are advanced and, therefore, expects to continue to incur losses and negative operating cash flows for the next several years. Absent additional funding or adjustments to currently planned operating activities, and in view of the uncertainties regarding future royalty revenue on sales of Relenza ® ® The Company reviews its operations and clinical plans on a continuing basis, including its commitments for upcoming clinical trials. The Company plans to finance its operations with royalty revenue on sales of Relenza® and Inavir®, additional equity or debt financing arrangements, and potentially with additional funding from government contracts or strategic alliances with partner companies. The availability and amount of such funding is not certain. The uncertainties inherent in the Company’s future operations and in its ability to obtain additional funding raise substantial doubt about its ability to continue as a going concern beyond one year from the date these financial statements are issued. The financial statements do not include any adjustments that might result from the outcome of this uncertainty. While management believes its plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. If adequate funds are not available, the Company may be required to reduce operating expenses, delay or reduce the scope of its product development programs, obtain funds through arrangements with others that may require the Company to relinquish rights to certain of its technologies or products that the Company would otherwise seek to develop or commercialize itself, or cease operations .

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	NOTE 2. Summary of Significant Accounting Policies Basis of Presentation – The Company has prepared the accompanying condensed consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to these rules and regulations. These condensed consolidated financial statements should be read in conjunction with the audited financial statements of Vaxart Biosciences, Inc. and footnotes related thereto for the year ended December 31, 2017, included in our Form 8-K/A filed with the SEC on April 2, 2018. In the opinion of management, the unaudited condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position and the results of its operations and cash flows. The results of operations for such interim periods are not necessarily indicative of the results to be expected for the full year. Basis of Consolidation – The condensed consolidated financial statements include the financial statements of Vaxart, Inc. and its subsidiaries. All significant transactions and balances between Vaxart, Inc. and its subsidiaries have been eliminated in consolidation. Use of Estimates – The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and disclosure of contingent assets and liabilities in the financial statements and accompanying notes. Actual results and outcomes could differ from these estimates and assumptions . Foreign Currencies – Foreign exchange gains and losses for assets and liabilities of the Company’s non-U.S. foreign exchange gain (loss), net . The Company has no subsidiaries Cash and Cash Equivalents – Short-Term Investments – Concentration of Credit Risk – The primary focus of the Company’s investment strategy is to preserve capital and meet liquidity requirements. The Company’s investment policy addresses the level of credit exposure by limiting the concentration in any one corporate issuer or sector and establishing a minimum allowable credit rating. The Company generally requires no collateral from its customers. Accounts Receivable – net of estimated returns, Inavir ® ® An allowance for uncollectible accounts will be recorded based on a combination of historical experience, aging analysis, and information on specific accounts, with related amounts recorded as a reserve against revenue recognized. Property and Equipment – The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Office and computer equipment 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life Intangible Assets – Intangible assets comprise developed technology, intellectual property and, until it was considered fully impaired (see Note 5), in-process research and development. Intangible assets are carried at cost less accumulated amortization. Amortization is computed using the straight-line method over useful lives ranging from 1.3 to 11.75 years for developed technology and 20 years for intellectual property. In-process research and development is considered to be indefinite-lived and is not amortized, but is subject to impairment testing. The Company assessed its in-process research and development as fully impaired in the three months ended June 30, 2018 (see Note 5). Impairment of Long-Lived Assets – . Accrued Clinical and Manufacturing Expenses – condensed . The Company estimates the amount of services provided through discussions with internal personnel and external service providers as to the progress or stage of completion of the services and the agreed-upon fee to be paid for such services. The Company makes significant judgments and estimates in determining the accrued balance in each reporting period. As actual costs become known, it adjusts its accrued estimates. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed, the number of subjects enrolled, and the rate of enrollment may vary from its estimates and could result in the Company reporting amounts that are too high or too low in any particular period. The Company’s accrued expenses are dependent, in part, upon the receipt of timely and accurate reporting from contract research organizations and other third-party service providers. To date, the Company has not experienced any material differences between accrued costs and actual costs incurred . Convertible Preferred Stock Warrant Liability – condensed . In the event that the terms of the warrant change such that liability accounting is no longer required, the fair value on the date of such change is released to equity. Convertible Promissory Notes Embedded Derivative Liability – financial instruments condensed . Revenue Recognition – The Company recognizes revenue when it transfers control of promised goods or services to its customers, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition, the Company performs the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account. Revenue from royalties earned as a percentage of sales, including milestone payments based on achieving a specified level of sales, where a license is deemed to be the predominant item to which the royalties relate, is recognized as revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). The Company performs research and development work under its cost‑plus‑fixed‑fee contract with HHS BARDA. The Company recognizes revenue under research contracts only when a contract has been executed and the contract price is fixed or determinable. Revenue from the HHS BARDA contract is recognized in the period during which the related costs are incurred and the related services are rendered, provided that the applicable conditions under the contract have been met. Costs of contract revenue are recorded as a component of operating expenses in the condensed consolidated statements of operations . Under the cost reimbursable contract with HHS BARDA, the Company is reimbursed for allowable costs, and recognizes revenue as allowable costs are incurred and the fixed-fee is earned. Reimbursable costs under the contract primarily include direct labor, subcontract costs, materials, equipment, travel, and approved overhead and indirect costs. Fixed fees under cost reimbursable contracts are earned in proportion to the allowable costs incurred in performance of the work relative to total estimated contract costs, with such costs incurred representing a reasonable measurement of the proportional performance of the work completed. Under the HHS BARDA contract, certain activities must be pre-approved in order for their costs to be deemed allowable direct costs. The HHS BARDA contract provides the U.S. government the ability to terminate the contract for convenience or to terminate for default if the Company fails to meet its obligations as set forth in the statement of work. Management believes that if the government were to terminate the HHS BARDA contract for convenience, the costs incurred through the effective date of such termination and any settlement costs resulting from such termination would be allowable costs. Payments to the Company under cost reimbursable contracts, such as this contract, are provisional payments subject to adjustment upon annual audit by the government. Management believes that revenue for periods not yet audited has been recorded in amounts that are expected to be realized upon final audit and settlement. When the final determination of the allowable costs for any year has been made, revenue and billings may be adjusted accordingly in the period that the adjustment is known. Research and Development Costs – Research and development costs are expensed as incurred. Research and development costs consist primarily of salaries and benefits, stock-based compensation, consultant fees, third-party costs for conducting clinical trials and the manufacture of clinical trial materials, certain facility costs and other costs associated with clinical trials. Payments made to other entities are under agreements that are generally cancelable by the Company. Advance payments for research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related services are performed. Stock-Based Compensation – The Company measures the fair value of all stock-based awards, including stock options, to employees and, since April 1, 2018, to nonemployees, on the grant date and records the fair value of these awards, net of estimated forfeitures, to compensation expense over the service period. Prior to April 1, 2018, the fair value of awards to nonemployees was measured on the date of performance at the fair value of the consideration received or the fair value of the equity instruments issued, whichever was more reliably measured. The fair value of options is estimated using the Black-Scholes valuation model . Net Income (Loss) Per Share Attributable to Common Stockholders – Basic net income (loss) per share is computed by dividing net income (loss), as adjusted for dividends on the Series B and Series C convertible preferred stock in the period, by the weighted average number of common shares outstanding during the period, without consideration of potential common shares. Diluted net income (loss) per common share is computed giving effect to all potential dilutive common shares, comprising common stock issuable upon exercise of stock options and warrants. The Company uses the treasury-stock method to compute diluted income (loss) per share with respect to its stock options and warrants. For purposes of this calculation, options and warrants to purchase common stock are considered to be potential common shares and are only included in the calculation of diluted net income per share when their effect is dilutive. In the event of a net loss, the effects of all potentially dilutive shares are excluded from the diluted net loss per share calculation as their inclusion would be antidilutive. Recently Adopted Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting. In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350) Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805) Clarifying the Definition of a Business clarifies the definition of a business to help companies evaluate whether acquisition or disposal transactions should be accounted for as asset groups or as businesses In August 2016, the FASB issued Accounting Standards Update (ASU) 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In May 2014, the FASB issued ASU 2014-09 , Revenue from Contracts with Customers (Topic 606) Revenue Recognition The Company has determined that its HHS BARDA government contract is not within the scope of ASU 2014-09 as the government entity is not a customer under the agreement. . Recent Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02 Leases (Topic 842) The Company has reviewed all other significant newly-issued accounting pronouncements and concluded that they either are not applicable to the Company’s operations or no material effect is expected on its condensed consolidated financial statements as a result of future adoption.

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	NOTE 3. Business Combination On February 13, 2018, the Company acquired Aviragen in a reverse merger (see Note 1). On the date of the Merger, Aviragen had in-process research and development as it was conducting a Phase 2 trial, it had previously developed drugs that were licensed to others who brought them to market and it had a workforce that was considered to have the necessary skills, knowledge, and experience to perform a process that, when applied to the in-process research and development, was critical to the ability to convert it into outputs. Based on this evaluation, the Company determined that the Merger should be accounted for as a business combination. Since the date of the Merger, the results of Aviragen’s operations have been included in the condensed consolidated financial statements. As a result of the acquisition, the Company eliminated the majority of its debt and acquired a significant cash balance in exchange for equity securities. The total purchase price for Aviragen is summarized as follows (in thousands): Common stock $ 31,789 Total $ 31,789 In connection with the Aviragen acquisition, the Company allocated the total purchase consideration to the net assets and liabilities acquired, including identifiable intangible assets, based on their respective fair values at the acquisition date. The following table summarizes the preliminary allocation of the purchase price to the fair value of the respective assets and liabilities acquired, adjustments made since the acquisition date and the allocation as of September 30, 2018: As of February 13, 2018 Adjustments As of September 30, 2018 (in thousands) Cash and cash equivalents $ 25,525 $ — $ 25,525 Accounts receivable 14,666 — 14,666 Prepaid expenses 446 (10) 436 Property and equipment 170 — 170 Intangible assets: Developed technology (1) 22,400 — 22,400 In-process research and development (2) 1,600 — 1,600 Total assets 64,807 (10) 64,797 Accounts payable (3,379) 75 (3,304) Other current liabilities (6,351) (393) (6,744) L iability related to sale of future royalties (16,300) — (16,300) Net assets acquired 38,777 (328) 38,449 Purchase price (31,789) — (31,789) Bargain purchase gain (3) $ 6,988 $ (328) $ 6,660 __________ (1) Developed technology comprises Inavir ® ® (2) In-process research and development (see Note 5) related to teslexivir, or BTA074, a direct-acting antiviral that, at the time of the Merger, was being actively developed as a treatment for genital warts. The preliminary valuation was prepared by an independent third party based on estimated discounted cash flows based on probability-weighted future development expenditures and revenue streams provided by the Company’s management. (3) The bargain purchase gain represents the excess of a preliminary valuation of the fair value of tangible and identified intangible assets, less liabilities, acquired over the purchase price. In addition, the Company incurred and expensed costs directly related to the Merger totaling approximately $1.4 million, of which approximately $0.5 million was incurred in the nine months ended , 2018, substantially all in the three months ended March 31, 2018, and is included in in the condensed consolidated statement of operations and comprehensive loss Selected amounts related to Aviragen’s business included in the Company’s condensed consolidated statement of operations for the three and nine months ended September 30, 2018, are as follows: Period Ended September 30, 2018 Three Months Nine Months (in thousands) Revenue $ 87 $ 1,068 Net loss $ (2,625) $ (5,267) The unaudited pro forma information in the table below summarizes the combined results of operations of Vaxart Biosciences, Inc. with those of Aviragen as though these entities were combined as of January 1, 2017. The results of Aviragen’s business for the three and nine months ended September 30, 2017, are based on the actual unaudited financial statements prepared for the three and nine months ended September 30, 2017, and for the three and nine months ended September 30, 2018, are based on the Company’s results of operations, with the year-to-date results increased by Aviragen’s activities in the forty-three days prior to the closing of the Merger. The pro forma financial information for all periods presented also includes the removal of direct acquisition-related costs, the reduction in interest expense on borrowing converted into equity in the reverse merger, and the actual depreciation and amortization that would have been charged assuming the fair value adjustments to property and equipment and intangible assets had been applied as of January 1, 2017. This unaudited pro forma information is summarized as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) (in thousands) Total revenue $ 281 $ 3,586 $ 13,928 $ 12,640 Net loss $ (6,133) $ (5,854) $ (8,385) $ (23,340) The pro forma financial information as presented above is for informational purposes only and is not indicative of the consolidated results of operations of future periods or the results of operations that would have been achieved had the acquisition had taken place on January 1, 2017.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	NOTE 4. Fair Value of Financial Instruments Fair value accounting is applied for all financial assets and liabilities and nonfinancial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis (at least annually). Financial instruments include cash and cash equivalents, short‑term investments, accounts receivable, accounts payable and accrued liabilities that approximate fair value due to their relatively short maturities. As short‑term investments are classified as held‑to‑maturity, they are recorded at their amortized cost. Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with inputs used to measure their fair values. The accounting guidance for fair value provides a framework for measuring fair value and requires certain disclosures about how fair value is determined. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance also establishes a three‑level valuation hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows : Level 1 – Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 – Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 – Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. The Company’s money market funds are classified within Level 1 of the fair value hierarchy and are valued based on quoted prices in active markets for identical securities. The Company’s corporate bonds and commercial paper are classified within Level 2 of the fair value hierarchy and are valued based on quoted prices for similar assets or prices derived from observable market data. Level 3 liabilities consist of convertible promissory notes embedded derivative liabilities and a convertible preferred stock warrant liability as they are valued by using inputs that are unobservable in the market. The determination of the fair values of the convertible promissory notes embedded derivative is discussed in Note 8. The following tables present the Company’s financial assets and liabilities that are measured at fair value at September 30, 2018 and December 3 1, 2017: Level 1 Level 2 Level 3 Total September 30 , 2018 (in thousands) Recurring Financial Assets: Money Market Funds $ 14 $ — $ — $ 14 Corporate Bonds — — — — Total assets $ 14 $ — $ — $ 14 Level 1 Level 2 Level 3 Total September 30 , 2018 (in thousands) Recurring Financial Liabilities: Convertible promissory notes embedded derivative liability $ — $ — $ — $ — Convertible preferred stock warrant liability — — — — Total liabilities $ — $ — $ — $ — Level 1 Level 2 Level 3 Total December 3 1, 2017 (in thousands) Recurring Financial Assets: Money Market Funds $ 1,192 $ — $ — $ 1,192 Corporate Bonds — 1,415 — 1,415 Total assets $ 1,192 $ 1,415 $ — $ 2,607 Level 1 Level 2 Level 3 Total December 3 1, 2017 (in thousands) Recurring Financial Liabilities: Convertible promissory notes embedded derivative liability $ — $ — $ — $ — Convertible preferred stock warrant liability — — 67 67 Total liabilities $ — $ — $ 67 $ 67 The following tables present a reconciliation of all liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the nine months ended September 30 , 2018 and 2017: Convertible Convertible Promissory Preferred Stock Notes Embedded Warrant Liability Derivative Liability Total (in thousands) Balance at January 1, 2018 $ 67 $ — $ 67 Issuances — — — Revaluation loss included in gain (loss) on revaluation of financial instruments, net 3 — 3 Settlements (70) — (70) Balance at September 30, 2018 $ — $ — $ — Total losses included in other income and (expenses) attributable to liabilities still held as of September 30, 2018 $ — $ — $ — Convertible Convertible Promissory Preferred Stock Notes Embedded Warrant Liability Derivative Liability Total (in thousands) Balance at January 1, 2017 $ 134 $ 3,280 $ 3,414 Issuances — — — Revaluation gains included in gain (loss) on revaluation of financial instruments, net (46) (920) (966) Settlements — — — Balance at September 30, 2017 $ 88 $ 2,360 $ 2,448 Total gains included in other income and (expenses) attributable to liabilities still held as of September 30, 2017 $ 46 $ 920 $ 966

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block Supplement [Abstract]
Supplemental Balance Sheet Disclosures [Text Block]	NOTE 5. Balance Sheet Components (a) Cash Equivalents and Short-Term Investments Cash equivalents and short‑term investments, all of which are classified as held‑to‑maturity securities and mature within one year, consisted of the following: September 30, 2018 Gross Gross Estimated Amortized Unrecognized Unrecognized Fair Carrying Cost Gains Losses Value Value (in thousands) Money market funds $ 14 $ — $ — $ 14 $ 14 Corporate bonds — — — — — Total $ 14 $ — $ — $ 14 $ 14 Reported as: Cash equivalents $ 14 $ — $ — $ 14 $ 14 Short-term investments — — — — — Total $ 14 $ — $ — $ 14 $ 14 December 31, 2017 Gross Gross Estimated Amortized Unrecognized Unrecognized Fair Carrying Cost Gains Losses Value Value (in thousands) Money market funds $ 1,192 $ — $ — $ 1,192 $ 1,192 Corporate bonds 1,415 — — 1,415 1,415 Total $ 2,607 $ — $ — $ 2,607 $ 2,607 Reported as: Cash equivalents $ 1,192 $ — $ — $ 1,192 $ 1,192 Short-term investments 1,415 — — 1,415 1,415 Total $ 2,607 $ — $ — $ 2,607 $ 2,607 (b) Accounts Receivable, Net of Allowance Accounts receivable, net of allowance, comprises the following: September 30, 2018 December 31, 2017 (in thousands) Royalties receivable $ 109 $ — Government contract - billed 65 477 Government contract - unbilled 82 153 Accounts receivable, net of allowance $ 256 $ 630 (c) Property and Equipment, Net Property and equipment, net consists of the following: September 30, 2018 December 31, 2017 (in thousands) Laboratory equipment $ 1,993 $ 1,565 Office and computer equipment 256 175 Leasehold improvements 332 226 Total property and equipment 2,581 1,966 Less: accumulated depreciation (1,522) (1,236) Property and equipment, net $ 1,059 $ 730 Depreciation expense was $130,000 and $91,000 for the three months ended September 30, 2018 and 2017, respectively, and $349,000 and $292,000 for the nine months ended September 30, 2018 and 2017, respectively. Leasehold improvements and furniture at the Company’s leased premises in Georgia, which has been subleased, commencing in November 2018, for less than the rental that the Company is obligated to pay (see Note 10), were assessed as impaired as of September 30, 2018, and accordingly an impairment charge of $106,000 has been charged to operating expenses. (d) Intangible Assets Intangible assets consist of the following: September 30, 2018 February 13, 2018 December 31, 2017 (in thousands) Purchased technology $ 22,400 $ 22,400 $ — In-process research and development — 1,600 — Intellectual property 80 80 80 Total cost 22,480 24,080 80 Less accumulated amortization 2,070 40 40 Intangible assets, net $ 20,410 $ 24,040 $ 40 Intangible asset amortization expense was $812,000 and $1,000 for the three months ended September 30, 2018 and 2017, respectively, and $2,030,000 and $3,000 for the nine months ended September 30, 2018 and 2017, respectively. Following the results of Phase 2 trials in June 2018, the in-process research and development was assessed as fully impaired in the three months ended June 30, 2018, with the $1.6 million acquired in the Merger (see Note 3) being charged to operating expenses. As of September 30, 2018, the estimated future amortization expense by year is as follows (in thousands): Year Ending December 31, 2018 (three months remaining) $ 812 2019 2,254 2020 1,757 2021 1,757 2022 1,757 Thereafter 12,073 Total $ 20,410 (e) Other Accrued Liabilities Accrued liabilities consist of the following: September 30, 2018 December 31, 2017 (in thousands) Accrued compensation $ 1,015 $ 1,320 Accrued clinical and manufacturing expenses 84 69 Accrued professional and consulting services 64 113 Reserve for return of royalties 327 — Deferred rent 38 21 Convertible preferred stock warrant liability — 67 Other 149 15 Total $ 1,677 $ 1,605

Revenue

Revenue	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	NOTE 6. Revenue U.S. Government HHS BARDA Contract In September 2015, HHS BARDA awarded the Company a contract to support the advanced development of a more effective and universal influenza vaccine to improve seasonal and pandemic influenza preparedness. On each of May 25 and July 18, 2017, and June 28, 2018, the Company entered into a Modification of Contract with HHS BARDA, the combined effect being to increase the value of the existing $14 million contract by $1.7 million and to extend it through September 30, 2018. The modified contract is a cost-plus-fixed-fee contract, which reimburses the Company for allowable direct contract costs plus allowable indirect costs and a fixed-fee, totaling $15.7 million. The Company recognized revenue of $194,000 and $915,000 during the three months ended September 30, 2018 and 2017, respectively, and $1,324,000 and $5,079,000 during the nine months ended September 30, 2018 and 2017, respectively. Billings under the contract are based on approved provisional indirect billing rates, which permit recovery of fringe benefits, overhead and general and administrative expenses. Indirect rates as well as allowable costs are subject to audit by HHS BARDA on an annual basis. Management believes that revenues recognized to date have been recorded in amounts that are expected to be realized upon final audit and settlement. When the final determination of the allowable costs for any year has been made, revenue and billings may be adjusted accordingly in the period that the adjustments are known and collection is probable. Costs relating to contract acquisition are expensed as incurred. The Company does not consider any of the revenue recorded as of September 30, 2018 or 2017, to be at risk of reversal. Royalty agreements Aviragen entered into a royalty-bearing research and license agreement with GlaxoSmithKline, plc (“GSK”) in 1990 for the development and commercialization of zanamivir, a neuraminidase inhibitor marketed by GSK as Relenza ® ® ® ® September 30, 2018, was $87,000 and $498,000, respectively. The Company also generates royalty revenue from the sale of Inavir ® ® ® ® September 30, 2018, was $552,000. No such revenue was recognized in the three months ended 30, 2018, and there was no non-cash royalty revenue payable to HealthCare Royalty Partners III, L.P. (“HCRP”) (See Note 7). in Japan, for which $29,000 was included in income tax expense in the nine months ended 30, 2018, all in the six months ended June 30, 2018.

Liabilities Related to Sale of

Liabilities Related to Sale of Future Royalties	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block [Abstract]
Deferred Revenue Disclosure [Text Block]	NOTE 7. Liabilities Related to Sale of Future Royalties In April 2016, Aviragen entered into a Royalty Interest Acquisition Agreement (the “HCRP Agreement”) with HCRP. Under the Agreement, HCRP made a $20.0 million cash payment to Aviragen in consideration for acquiring certain royalty rights (“Royalty Rights”) related to the approved product Inavir ® Under the relevant accounting guidance, due to a limit on the amount of royalties that HCRP can earn under the arrangement, this transaction was accounted for as a liability that will be amortized using the interest method over the life of the arrangement. The Company has no obligation to pay any amounts to HCRP other than to pass through to HCRP its share of royalties as they are received from Daiichi Sankyo. In order to record the amortization of the liability, the Company is required to estimate the total amount of future royalty payments to be received under the License Agreement and the payments that will be passed through to HCRP over the life of this agreement. The sum of the pass-through amounts less the net proceeds received will be recorded as non-cash interest expense over the life of the liability. Consequently, the Company imputes interest on the unamortized portion of the liability and records non-cash interest expense using an estimated effective interest rate. The Company will periodically assess the expected royalty payments, and to the extent such payments are greater or less than the initial estimate, the Company will adjust the amortization of the liability and interest rate. As a result of this accounting, even though the Company does not retain HCRP’s share of the royalties, it will continue to record non-cash revenue related to those royalties until the amount of the associated liability and related interest is fully amortized. The following table shows the activity within the liability account since the Merger (in thousands): Total Liability related to sale of future royalties, February 13, 2018 $ 16,300 Non-cash royalty revenue paid to HCRP (18) Non-cash interest expense recognized 1,298 Total Liability related to sale of future royalties, 30, 2018 $ 17,580

Convertible Promissory Notes, R

Convertible Promissory Notes, Related Parties	9 Months Ended
	Sep. 30, 2018
Convertible Promissory Notes, Related Party [Abstract]
Convertible Promissory Notes, Related Party [Text Block]	NOTE 8. Convertible Promissory Notes, Related Parties On December 10, 2014, the Company entered into a note purchase agreement with certain existing preferred stockholders under which the Company issued convertible promissory notes during December 2014 for total proceeds of $18.4 million. On November 20, 2015, the Company entered into a second note purchase agreement with certain existing preferred stockholders under which the Company issued convertible promissory notes during November and December 2015 for total proceeds of $11.0 million. These notes were issued with the same terms as the notes issued in 2014. As the holders of the convertible promissory notes each have an equity ownership in the Company, the convertible promissory notes were considered to be a related‑party transaction. The convertible promissory notes bore interest at a rate of 8.0% per annum. The principal and accrued interest on the notes were automatically convertible, upon a future issuance of convertible preferred stock having total proceeds of at least $25.0 million, into that same stock at a conversion price equal to 90% of the price paid by other investors in the financing event. Upon a liquidation event, such as an acquisition or initial public offering, at the election of the majority of the noteholders in each issuance, the principal and accrued interest on the notes could either (i) be paid in full at the initial closing of the liquidation event, or (ii) automatically convert into the Company’s Series C convertible preferred stock at a conversion price based on a specified valuation. After two years, if the notes had not been converted, the holders of a majority of the principal amount had the option to require the entire principal balance and accrued interest to become due and payable. However, in December 2016, in conjunction with the loan agreement with Oxford Finance (see note 9), all of the holders of convertible promissory notes signed subordination agreements, under which they agreed not to demand or receive any payment until all amounts owed to Oxford Finance under the loan agreement were fully paid in cash, thus extending the due dates of the promissory notes potentially to January 2021. This change reflected a debt modification that was not considered substantially significant. Accordingly, the Company did not apply extinguishment accounting, but accounted for the modification on a prospective basis. The convertible promissory notes had redemption features that were determined to be a compound embedded derivative requiring bifurcation and separate accounting at estimated fair value. The estimated fair value of the embedded derivative upon issuance was a liability of $1.9 million for the notes issued in 2014 and $1.3 million for the notes issued in 2015. The estimated fair value of these derivative instruments was recognized as a debt discount and as an embedded derivative liability on the balance sheet upon issuance of the convertible promissory notes. The embedded derivative required periodic re‑measurements to fair value while the instruments were still outstanding (see Note 4). There was no beneficial conversion feature as the conversion feature value was accounted for in the embedded derivative. The Company estimated the fair value of the compound embedded derivative utilizing a Monte Carlo Simulation model. The inputs used to determine the estimated fair value of the embedded derivative instrument included the probability of an underlying event triggering the redemption event and its timing prior to the maturity date of the convertible promissory notes. The fair value measurement was based upon significant inputs not observable in the market, including a valuation of the Company performed by an independent third-party at each balance sheet date. By December 31, 2017, the embedded derivative had zero value because the Merger (see Note 1), which was considered 90% probable of occurring, would not have triggered redemption and, had the Merger not occurred, it was unlikely that the Company would have found an alternative source of financing on favorable terms, so there would have been zero redemption value. The embedded derivative was extinguished when the Merger occurred on February 13, 2018. The Company incurred total debt issuance costs of $20,000 in connection with the 2014 issuance and $7,000 in connection with the 2015 issuance. The debt issuance costs, which were recorded as an additional debt discount, were being amortized over the term of the notes. The Company’s accrued interest associated with the convertible promissory notes amounted to $6.3 million and the unamortized debt discount to $0.4 million as of December 31, 2017. On February 13, 2018, the balance of the convertible promissory notes was $35.6 million, comprising accrued interest associated with the convertible promissory notes amounted to $6.6 million plus principal of $29.4 million, offset by the unamortized debt discount to $0.4 million. On that date, in conjunction with the Merger, the convertible promissory notes were exchanged for 1,571,702 shares of the Company’s common stock which, based on the closing stock price of $9.05, had a value of $14.2 million. The difference of $21.4 million was recorded as a capital contribution .

Secured Promissory Note Payable

Secured Promissory Note Payable to Oxford Finance	9 Months Ended
	Sep. 30, 2018
Secured Promissory Note Payable [Abstract]
Secured Promissory Note Payable [Text Block]	NOTE 9. Secured Promissory Note Payable to Oxford Finance On December 22, 2016, the Company entered into a loan and security agreement (the “Loan Agreement”) with Oxford Finance, under which the Company borrowed $5.0 million. The $5.0 million loan, which bears interest at 30-day U.S. LIBOR plus 6.17%, is evidenced by a secured promissory note and is repayable over four years, with interest only payable over the first 12 months and the balance fully amortized over the subsequent 36 months. The loan is secured by substantially all the Company’s assets, except for intellectual property. In conjunction with the execution of the Loan Agreement, all the holders of convertible promissory notes signed subordination agreements, under which they agreed to subordinate in favor of Oxford Finance all amounts due under their promissory notes and any security interest in the Company’s property. In addition, the holders of the notes agreed that they would not demand or receive any payment until all amounts owed to Oxford Finance under the Loan Agreement have been fully paid in cash. Upon repayment, an additional final payment equal to $325,000 is due, which is being accreted as interest expense over the term of the loan using the effective‑interest method. In connection with the Loan Agreement, the Company issued a warrant to Oxford Finance to purchase 7,563 shares of its Series C convertible preferred stock at an exercise price of $33.11 per share (the “Warrant”). The fair value of the Warrant at the date of issuance was approximately $134,000, which was recorded as debt discount and is being amortized as interest expense over the term of the loan using the effective‑interest method. The annual effective interest rate of the note, including the accretion of the final payment and the amortization of the debt discount, is approximately 10.5%. The Company recorded interest expense related to the Loan Agreement of $114,000 and $131,000 during the three months ended September 30, 2018 and 2017, respectively, of which $87,000 and $93,000 was paid, respectively, and recorded interest expense of $366,000 and $386,000 during the nine months ended September 30, 2018 and 2017, respectively, of which $276,000 and $241,000 was paid, respectively. The Warrant provided that if the share price at the next equity financing was less than the Warrant exercise price, then the Warrant would be for the new class of shares, the exercise price would be the new class share price, and the number of shares would be calculated by dividing $250,000 by the new class share price. Due to this anti-dilution protection, the Company determined that the Warrant needed to be recorded as a liability, and therefore estimated the fair value of the Warrant upon issuance and at each balance sheet date, with any changes in the fair value being recorded within the gain (loss) on revaluation of financial instruments line in the statements of operations and comprehensive loss. Due to the antidilution protection, following the Merger, the Warrant was amended to allow the holder to purchase 10,914 shares of common stock at an exercise price of $22.99 per share. Since the amended Warrant contains no non-standard antidilution protections or similar features, the fair value of approximately $70,000 on February 13, 2018, was transferred to equity.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	NOTE 10. Commitments and Contingencies (a) Leases The Company has five office and research and development facilities in South San Francisco, California, under noncancelable operating leases. The principal lease, for office and research and development premises, expires on April 30, 2020, subject to the Company’s option to extend the lease at the then market rate for an additional five year period. The remaining four leases all expire between December 31, 2018 and August 31, 2019. In addition, as a result of the Merger, the Company also leases office space in Alpharetta, Georgia, under a lease expiring on February 28, 2021, which, commencing in November 2018, the Company has subleased for the remainder of the lease term for less than it is required to pay under the head lease and accordingly it will record a lease loss charge of approximately $0.2 million on the cease-use date in the three months ending December 31, 2018 (see Note 5). Rent expense is recognized on a straight‑line basis over the noncancelable term of each operating lease and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability, which is included within accrued expenses. Rent expense was $623,000 and $456,000 for the nine months ended September 30, 2018 and 2017, respectively. Under the terms of the lease agreements, the Company is also responsible for certain insurance, property tax and maintenance expenses. The Company also leases equipment under three operating leases that expire between May and September 2019. Future minimum payments under operating leases as of September 30, 2018, are as follows (in thousands): Year ending December 31, 2018 (three months remaining) $ 271 2019 781 2020 411 2021 56 Thereafter — Total $ 1,519 (b) Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend indemnified parties for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third‑party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance. (c) Litigation From time to time the Company may be involved in claims arising in connection with its business. Based on information currently available, the Company believes that the amount, or range, of reasonably possible losses in connection with any pending actions against it in excess of established reserves, in the aggregate, not to be material to its consolidated financial condition or cash flows. However, losses may be material to the Company’s operating results for any particular future period, depending on the level of income or loss for such period.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	NOTE 11. Stockholders’ Equity (a) Convertible Preferred Stock The Company is authorized to issue 5,000,000 shares of preferred stock, $0.10 par value per share. The Company’s board of directors may, without further action by the stockholders, fix the rights, preferences, privileges and restrictions of up to an aggregate of 5,000,000 shares of preferred stock in one or more series and authorize their issuance. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of our common stock. The issuance of preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deterring or preventing a change of control or other corporate action. No shares of preferred stock are currently outstanding, and we have no present plan to issue any shares of preferred stock. All of Private Vaxart’s convertible preferred stock was converted into common stock on February 13, 2018, in conjunction with the Merger. As of December 31, 2017, convertible preferred stock consisted of the following: Shares Shares Net Liquidation (in thousands) (in thousands) Series A 94,988 94,988 $ 2,949 $ 2,737 Series B 747,095 520,973 16,115 17,219 Series C 820,088 605,103 19,877 20,000 Total 1,662,171 1,221,064 $ 38,941 $ 39,956 Significant provisions of the convertible preferred stock were as follows: Dividends The holders of Series B convertible preferred stock were entitled to receive non-compounding cumulative dividends, in preference to any dividends payable to holders of Series A convertible preferred stock or common stock, at the annual dividend rate of $2.64416 per share, as adjusted for any stock splits, stock dividends, recapitalizations, or the like. Such cumulative dividends were payable within ten days of demand of the holders of at least a majority of the then outstanding Series B convertible preferred stock or automatically upon a liquidation event. Dividends accumulated from the date of issuance and were payable, whether or not declared, before any dividend on Series A convertible preferred stock or common stock could be paid or declared. Series B convertible preferred shares issued as stock dividends were not entitled to cumulative dividends. The holders of Series B convertible preferred stock could elect whether the cumulative dividends would be paid in cash or in shares of Series B convertible preferred stock based on the original issue price of Series B convertible preferred stock of $33.05196 per share. In the event the board of directors declared a cash dividend in addition to the above cumulative dividends (a Special Dividend), the holders of Series B convertible preferred stock would have been entitled to receive, in preference to any dividends payable to the holders of Series A convertible preferred stock or common stock, a per share amount equal to the sum of: (a) the original issue price of Series B convertible preferred stock, and (b) all accrued and/or declared but unpaid dividends on such Series B convertible preferred stock, including the cumulative dividends. No dividends were declared during any of the periods presented. As of February 13, 2018, when the convertible preferred stock was converted into common stock, and December 31, 2017, accumulated and undeclared dividends for Series B convertible preferred stock were $7.6 million and $7.5 million, respectively ($15.78 per share and $15.46 per share, respectively, of the 483,387 shares of outstanding Series B convertible preferred stock on which dividends accrued). On February 13, 2018, in conjunction with the Merger, the Series B convertible preferred stock and the related accumulated dividends were converted into 599,259 and 265,340 shares of common stock, respectively. The holders of Series A convertible preferred stock were entitled to receive noncumulative dividends, in preference to any dividends payable to holders of common stock, at the annual dividend rate of $2.30449 per share, as adjusted for any stock splits, stock dividends, recapitalizations, or the like, if declared by the board of directors. On February 13, 2018, in conjunction with the Merger, the Series A convertible preferred stock was converted into 104,065 shares of common stock. Conversion Liquidation Voting Protective Provisions Redemption (b) Common Stock Except as otherwise required by law or as otherwise provided in any certificate of designation for any series of preferred stock, the holders of common stock possess all voting power for the election of the Company’s directors and all other matters requiring stockholder action. Holders of common stock are entitled to one vote per share on matters to be voted on by stockholders. Holders of common stock are entitled to receive such dividends, if any, as may be declared from time to time by the Company’s board of directors in its discretion out of funds legally available therefore. In no event will any stock dividends or stock splits or combinations of stock be declared or made on common stock unless the shares of common stock at the time outstanding are treated equally and identically. As of September 30, 2018, no dividends had been declared by the board of directors. In the event of the Company’s voluntary or involuntary liquidation, dissolution, distribution of assets or winding-up, the holders of the common stock will be entitled to receive an equal amount per share of all of the Company’s assets of whatever kind available for distribution to stockholders, after the rights of the holders of the preferred stock have been satisfied. There are no sinking fund provisions applicable to the common stock. The Company had shares of common stock reserved for issuance as follows: September 30, 2018 December 31, 2017 Convertible preferred stock outstanding — 1,221,064 Options issued and outstanding 960,888 304,850 Available for future grants of equity awards 127,652 — Cumulative convertible preferred stock dividends — 441,096 Common stock warrants 10,914 10,914 Total 1,099,454 1,977,924

Equity Incentive Plans

Equity Incentive Plans	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	NOTE 12. Equity Incentive Plans Prior to the Merger, the Company issued equity awards for compensation purposes to employees, directors and consultants under the Company’s 2007 Equity Incentive Plan (the “2007 Plan”). The 2007 Plan expired in July 2017. As of September 30, 2018, the Company had no shares of common stock available for issuance under the 2007 Plan. Equity awards under the 2007 Plan do not become available for future issuance if such awards are forfeited or otherwise terminate. Each stock option to acquire shares of Private Vaxart stock, whether vested or unvested, that had not previously been exercised was assumed in the Merger. In November 2016, Aviragen’s stockholders approved the 2016 Equity Incentive Plan (“2016 Equity Plan”), under which all outstanding awards under their previous plans became available for issuance under the 2016 Equity Plan if such awards are forfeited or otherwise terminate. The purpose of the 2016 Equity Plan is to assist the Company in attracting and retaining valued employees, consultants and non-employee directors by offering them a greater stake in the Company’s success and a closer identity with it, and to encourage ownership of the Company’s shares by such persons. Under the 2016 Equity Plan, the Company is authorized to issue incentive stock options (“ISOs”), non-qualified stock options (“NQSOs”), restricted stock (“RSAs”) and restricted stock units (“RSUs”). Awards that expire or are canceled generally become available for issuance again under the 2016 Equity Plan. The number of shares of the Company’s common stock available under the 2016 Equity Plan will be subject to adjustment in the event of a stock split, stock dividend or other extraordinary dividend, or other similar change in the Company’s common stock or capital structure. Awards may vest over varying periods, as specified by the Company’s Board of Directors for each grant, and have a maximum term of ten years from the grant date. A summary of stock option transactions in the nine months ended September 30, 2018, is as follows: Weighted Shares Number of Average Available Options Exercise For Grant Outstanding Price Balance at January 1, 2018 — 304,850 $ 9.50 Assumed on consummation of Merger 291,102 627,106 $ 26.33 Granted (431,100) 431,100 $ 5.17 Exercised — (2,013) $ 6.49 Forfeited 14,000 (32,403) $ 7.19 Canceled 230,923 (367,752) $ 35.11 $ Balance at September 104,925 960,888 $ 8.82 In addition, the 2016 Equity Plan has a reserve of 22,727 shares available for future issuance as RSAs and RSUs. As of September The weighted average grant date fair value of options awarded in the nine months ended September 30, 2018 and 2017, was $3.59 and $2.99, respectively. Fair values were estimated using the following assumptions: Nine Months Ended September 30, 2018 2017 Risk-free interest rate 2.80% 1.87% Expected term 5.96 Years 6.09 Years Expected volatility 79% 91 % Dividend yield 0% 0% Total stock‑based compensation recognized for options was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) (in thousands) Research and development $ 92 $ 69 $ 195 $ 207 General and administrative 91 52 192 167 Total stock-based compensation $ 183 $ 121 $ 387 $ 374 As of September 30, 2018, the unrecognized stock-based compensation cost related to outstanding stock options that are expected to vest was $1.3 million, which the Company expects to recognize over an estimated weighted average period of 2.96 years.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	NOTE 13. Net Loss Per Share Attributable to Common Stockholders The f Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Net loss $ (6,548) $ (2,173) $ (13,105) $ (8,507) Series B and C preferred dividend — (725) (339) (2,153) Net loss attributable to common stockholders $ (6,548) $ (2,898) $ (13,444) $ (10,660) Shares used to compute net loss per share, basic and diluted 7,141,189 135,658 6,038,001 135,658 Net loss per share attributable to common stockholders, basic and diluted $ (0.92) $ (21.36) $ (2.23) $ (78.58) No adjustment has been made to the net loss attributable to common stockholders as the effect would be anti-dilutive due to the net loss. The following potentially dilutive securities were excluded from the computation of diluted weighted average shares outstanding because they would have been antidilutive: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Options to purchase common stock 978,495 321,563 802,885 282,515 Warrant to purchase common stock 10,914 — 9,195 — Warrant to purchase convertible preferred stock — 7,563 1,191 7,563 Series B and C convertible preferred stock outstanding, including cumulative dividends — 1,545,224 285,797 1,545,224 Series A convertible preferred stock outstanding — 94,988 16,391 94,988 Convertible promissory notes, related party (as converted) — 731,899 247,557 731,899 Total potentially dilutive securities excluded from denominator of the diluted earnings per share computation 989,409 2,701,237 1,363,016 2,662,189

Accounting Policies, by Policy

Accounting Policies, by Policy (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation – The Company has prepared the accompanying condensed consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to these rules and regulations. These condensed consolidated financial statements should be read in conjunction with the audited financial statements of Vaxart Biosciences, Inc. and footnotes related thereto for the year ended December 31, 2017, included in our Form 8-K/A filed with the SEC on April 2, 2018. In the opinion of management, the unaudited condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position and the results of its operations and cash flows. The results of operations for such interim periods are not necessarily indicative of the results to be expected for the full year.
Consolidation, Policy [Policy Text Block]	Basis of Consolidation – The condensed consolidated financial statements include the financial statements of Vaxart, Inc. and its subsidiaries. All significant transactions and balances between Vaxart, Inc. and its subsidiaries have been eliminated in consolidation.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates – The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and disclosure of contingent assets and liabilities in the financial statements and accompanying notes. Actual results and outcomes could differ from these estimates and assumptions .
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currencies – Foreign exchange gains and losses for assets and liabilities of the Company’s non-U.S. foreign exchange gain (loss), net . The Company has no subsidiaries
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents –
Investment, Policy [Policy Text Block]	Short-Term Investments –
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentration of Credit Risk – The primary focus of the Company’s investment strategy is to preserve capital and meet liquidity requirements. The Company’s investment policy addresses the level of credit exposure by limiting the concentration in any one corporate issuer or sector and establishing a minimum allowable credit rating. The Company generally requires no collateral from its customers.
Receivables, Policy [Policy Text Block]	Accounts Receivable – net of estimated returns, Inavir ® ® An allowance for uncollectible accounts will be recorded based on a combination of historical experience, aging analysis, and information on specific accounts, with related amounts recorded as a reserve against revenue recognized.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment – The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Office and computer equipment 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life
Goodwill and Intangible Assets, Policy [Policy Text Block]	Intangible Assets – Intangible assets comprise developed technology, intellectual property and, until it was considered fully impaired (see Note 5), in-process research and development. Intangible assets are carried at cost less accumulated amortization. Amortization is computed using the straight-line method over useful lives ranging from 1.3 to 11.75 years for developed technology and 20 years for intellectual property. In-process research and development is considered to be indefinite-lived and is not amortized, but is subject to impairment testing. The Company assessed its in-process research and development as fully impaired in the three months ended June 30, 2018 (see Note 5).
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment of Long-Lived Assets – .
Accrued Clinical And Manufacturing Expenses Policy [Policy Text Block]	Accrued Clinical and Manufacturing Expenses – condensed . The Company estimates the amount of services provided through discussions with internal personnel and external service providers as to the progress or stage of completion of the services and the agreed-upon fee to be paid for such services. The Company makes significant judgments and estimates in determining the accrued balance in each reporting period. As actual costs become known, it adjusts its accrued estimates. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed, the number of subjects enrolled, and the rate of enrollment may vary from its estimates and could result in the Company reporting amounts that are too high or too low in any particular period. The Company’s accrued expenses are dependent, in part, upon the receipt of timely and accurate reporting from contract research organizations and other third-party service providers. To date, the Company has not experienced any material differences between accrued costs and actual costs incurred .
Convertible Preferred Stock Warrant Liability Policy [Policy Text Block]	Convertible Preferred Stock Warrant Liability – condensed . In the event that the terms of the warrant change such that liability accounting is no longer required, the fair value on the date of such change is released to equity.
Derivatives, Policy [Policy Text Block]	Convertible Promissory Notes Embedded Derivative Liability – financial instruments condensed .
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition – The Company recognizes revenue when it transfers control of promised goods or services to its customers, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition, the Company performs the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account. Revenue from royalties earned as a percentage of sales, including milestone payments based on achieving a specified level of sales, where a license is deemed to be the predominant item to which the royalties relate, is recognized as revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). The Company performs research and development work under its cost‑plus‑fixed‑fee contract with HHS BARDA. The Company recognizes revenue under research contracts only when a contract has been executed and the contract price is fixed or determinable. Revenue from the HHS BARDA contract is recognized in the period during which the related costs are incurred and the related services are rendered, provided that the applicable conditions under the contract have been met. Costs of contract revenue are recorded as a component of operating expenses in the condensed consolidated statements of operations . Under the cost reimbursable contract with HHS BARDA, the Company is reimbursed for allowable costs, and recognizes revenue as allowable costs are incurred and the fixed-fee is earned. Reimbursable costs under the contract primarily include direct labor, subcontract costs, materials, equipment, travel, and approved overhead and indirect costs. Fixed fees under cost reimbursable contracts are earned in proportion to the allowable costs incurred in performance of the work relative to total estimated contract costs, with such costs incurred representing a reasonable measurement of the proportional performance of the work completed. Under the HHS BARDA contract, certain activities must be pre-approved in order for their costs to be deemed allowable direct costs. The HHS BARDA contract provides the U.S. government the ability to terminate the contract for convenience or to terminate for default if the Company fails to meet its obligations as set forth in the statement of work. Management believes that if the government were to terminate the HHS BARDA contract for convenience, the costs incurred through the effective date of such termination and any settlement costs resulting from such termination would be allowable costs. Payments to the Company under cost reimbursable contracts, such as this contract, are provisional payments subject to adjustment upon annual audit by the government. Management believes that revenue for periods not yet audited has been recorded in amounts that are expected to be realized upon final audit and settlement. When the final determination of the allowable costs for any year has been made, revenue and billings may be adjusted accordingly in the period that the adjustment is known.
Research and Development Expense, Policy [Policy Text Block]	Research and Development Costs – Research and development costs are expensed as incurred. Research and development costs consist primarily of salaries and benefits, stock-based compensation, consultant fees, third-party costs for conducting clinical trials and the manufacture of clinical trial materials, certain facility costs and other costs associated with clinical trials. Payments made to other entities are under agreements that are generally cancelable by the Company. Advance payments for research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related services are performed.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation – The Company measures the fair value of all stock-based awards, including stock options, to employees and, since April 1, 2018, to nonemployees, on the grant date and records the fair value of these awards, net of estimated forfeitures, to compensation expense over the service period. Prior to April 1, 2018, the fair value of awards to nonemployees was measured on the date of performance at the fair value of the consideration received or the fair value of the equity instruments issued, whichever was more reliably measured. The fair value of options is estimated using the Black-Scholes valuation model .
Earnings Per Share, Policy [Policy Text Block]	Net Income (Loss) Per Share Attributable to Common Stockholders – Basic net income (loss) per share is computed by dividing net income (loss), as adjusted for dividends on the Series B and Series C convertible preferred stock in the period, by the weighted average number of common shares outstanding during the period, without consideration of potential common shares. Diluted net income (loss) per common share is computed giving effect to all potential dilutive common shares, comprising common stock issuable upon exercise of stock options and warrants. The Company uses the treasury-stock method to compute diluted income (loss) per share with respect to its stock options and warrants. For purposes of this calculation, options and warrants to purchase common stock are considered to be potential common shares and are only included in the calculation of diluted net income per share when their effect is dilutive. In the event of a net loss, the effects of all potentially dilutive shares are excluded from the diluted net loss per share calculation as their inclusion would be antidilutive.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting. In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350) Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805) Clarifying the Definition of a Business clarifies the definition of a business to help companies evaluate whether acquisition or disposal transactions should be accounted for as asset groups or as businesses In August 2016, the FASB issued Accounting Standards Update (ASU) 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In May 2014, the FASB issued ASU 2014-09 , Revenue from Contracts with Customers (Topic 606) Revenue Recognition The Company has determined that its HHS BARDA government contract is not within the scope of ASU 2014-09 as the government entity is not a customer under the agreement. . Recent Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02 Leases (Topic 842) The Company has reviewed all other significant newly-issued accounting pronouncements and concluded that they either are not applicable to the Company’s operations or no material effect is expected on its condensed consolidated financial statements as a result of future adoption.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule Of Property Plant And Equipment Useful Life [Table Text Block]	Laboratory equipment 5 years Office and computer equipment 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Schedule of Business Acquisitions by Acquisition, Equity Interest Issued or Issuable [Table Text Block]	Common stock $ 31,789 Total $ 31,789
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	As of February 13, 2018 Adjustments As of September 30, 2018 (in thousands) Cash and cash equivalents $ 25,525 $ — $ 25,525 Accounts receivable 14,666 — 14,666 Prepaid expenses 446 (10) 436 Property and equipment 170 — 170 Intangible assets: Developed technology (1) 22,400 — 22,400 In-process research and development (2) 1,600 — 1,600 Total assets 64,807 (10) 64,797 Accounts payable (3,379) 75 (3,304) Other current liabilities (6,351) (393) (6,744) L iability related to sale of future royalties (16,300) — (16,300) Net assets acquired 38,777 (328) 38,449 Purchase price (31,789) — (31,789) Bargain purchase gain (3) $ 6,988 $ (328) $ 6,660
Business Combination, Separately Recognized Transactions [Table Text Block]	Period Ended September 30, 2018 Three Months Nine Months (in thousands) Revenue $ 87 $ 1,068 Net loss $ (2,625) $ (5,267)
Business Acquisition, Pro Forma Information [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) (in thousands) Total revenue $ 281 $ 3,586 $ 13,928 $ 12,640 Net loss $ (6,133) $ (5,854) $ (8,385) $ (23,340)

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	Level 1 Level 2 Level 3 Total September 30 , 2018 (in thousands) Recurring Financial Assets: Money Market Funds $ 14 $ — $ — $ 14 Corporate Bonds — — — — Total assets $ 14 $ — $ — $ 14 Level 1 Level 2 Level 3 Total December 3 1, 2017 (in thousands) Recurring Financial Assets: Money Market Funds $ 1,192 $ — $ — $ 1,192 Corporate Bonds — 1,415 — 1,415 Total assets $ 1,192 $ 1,415 $ — $ 2,607
Fair Value, Liabilities Measured on Recurring Basis [Table Text Block]	Level 1 Level 2 Level 3 Total September 30 , 2018 (in thousands) Recurring Financial Liabilities: Convertible promissory notes embedded derivative liability $ — $ — $ — $ — Convertible preferred stock warrant liability — — — — Total liabilities $ — $ — $ — $ — Level 1 Level 2 Level 3 Total December 3 1, 2017 (in thousands) Recurring Financial Liabilities: Convertible promissory notes embedded derivative liability $ — $ — $ — $ — Convertible preferred stock warrant liability — — 67 67 Total liabilities $ — $ — $ 67 $ 67
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Convertible Convertible Promissory Preferred Stock Notes Embedded Warrant Liability Derivative Liability Total (in thousands) Balance at January 1, 2018 $ 67 $ — $ 67 Issuances — — — Revaluation loss included in gain (loss) on revaluation of financial instruments, net 3 — 3 Settlements (70) — (70) Balance at September 30, 2018 $ — $ — $ — Total losses included in other income and (expenses) attributable to liabilities still held as of September 30, 2018 $ — $ — $ — Convertible Convertible Promissory Preferred Stock Notes Embedded Warrant Liability Derivative Liability Total (in thousands) Balance at January 1, 2017 $ 134 $ 3,280 $ 3,414 Issuances — — — Revaluation gains included in gain (loss) on revaluation of financial instruments, net (46) (920) (966) Settlements — — — Balance at September 30, 2017 $ 88 $ 2,360 $ 2,448 Total gains included in other income and (expenses) attributable to liabilities still held as of September 30, 2017 $ 46 $ 920 $ 966

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block Supplement [Abstract]
Cash, Cash Equivalents and Investments [Table Text Block]	September 30, 2018 Gross Gross Estimated Amortized Unrecognized Unrecognized Fair Carrying Cost Gains Losses Value Value (in thousands) Money market funds $ 14 $ — $ — $ 14 $ 14 Corporate bonds — — — — — Total $ 14 $ — $ — $ 14 $ 14 Reported as: Cash equivalents $ 14 $ — $ — $ 14 $ 14 Short-term investments — — — — — Total $ 14 $ — $ — $ 14 $ 14 December 31, 2017 Gross Gross Estimated Amortized Unrecognized Unrecognized Fair Carrying Cost Gains Losses Value Value (in thousands) Money market funds $ 1,192 $ — $ — $ 1,192 $ 1,192 Corporate bonds 1,415 — — 1,415 1,415 Total $ 2,607 $ — $ — $ 2,607 $ 2,607 Reported as: Cash equivalents $ 1,192 $ — $ — $ 1,192 $ 1,192 Short-term investments 1,415 — — 1,415 1,415 Total $ 2,607 $ — $ — $ 2,607 $ 2,607
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	September 30, 2018 December 31, 2017 (in thousands) Royalties receivable $ 109 $ — Government contract - billed 65 477 Government contract - unbilled 82 153 Accounts receivable, net of allowance $ 256 $ 630
Property, Plant and Equipment [Table Text Block]	September 30, 2018 December 31, 2017 (in thousands) Laboratory equipment $ 1,993 $ 1,565 Office and computer equipment 256 175 Leasehold improvements 332 226 Total property and equipment 2,581 1,966 Less: accumulated depreciation (1,522) (1,236) Property and equipment, net $ 1,059 $ 730
Schedule of Finite-Lived Intangible Assets [Table Text Block]	September 30, 2018 February 13, 2018 December 31, 2017 (in thousands) Purchased technology $ 22,400 $ 22,400 $ — In-process research and development — 1,600 — Intellectual property 80 80 80 Total cost 22,480 24,080 80 Less accumulated amortization 2,070 40 40 Intangible assets, net $ 20,410 $ 24,040 $ 40
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Year Ending December 31, 2018 (three months remaining) $ 812 2019 2,254 2020 1,757 2021 1,757 2022 1,757 Thereafter 12,073 Total $ 20,410
Schedule of Accrued Liabilities [Table Text Block]	September 30, 2018 December 31, 2017 (in thousands) Accrued compensation $ 1,015 $ 1,320 Accrued clinical and manufacturing expenses 84 69 Accrued professional and consulting services 64 113 Reserve for return of royalties 327 — Deferred rent 38 21 Convertible preferred stock warrant liability — 67 Other 149 15 Total $ 1,677 $ 1,605

Liabilities Related to Sale o_2

Liabilities Related to Sale of Future Royalties (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block [Abstract]
Deferred Revenue, by Arrangement, Disclosure [Table Text Block]	Total Liability related to sale of future royalties, February 13, 2018 $ 16,300 Non-cash royalty revenue paid to HCRP (18) Non-cash interest expense recognized 1,298 Total Liability related to sale of future royalties, 30, 2018 $ 17,580

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Year ending December 31, 2018 (three months remaining) $ 271 2019 781 2020 411 2021 56 Thereafter — Total $ 1,519

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Schedule Of Convertible Preferred Stock [Table Text Block]	Shares Shares Net Liquidation (in thousands) (in thousands) Series A 94,988 94,988 $ 2,949 $ 2,737 Series B 747,095 520,973 16,115 17,219 Series C 820,088 605,103 19,877 20,000 Total 1,662,171 1,221,064 $ 38,941 $ 39,956
Schedule Of Common Stock Reserved For Issuance [Table Text Block]	September 30, 2018 December 31, 2017 Convertible preferred stock outstanding — 1,221,064 Options issued and outstanding 960,888 304,850 Available for future grants of equity awards 127,652 — Cumulative convertible preferred stock dividends — 441,096 Common stock warrants 10,914 10,914 Total 1,099,454 1,977,924

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation, Stock Options, Activity [Table Text Block]	Weighted Shares Number of Average Available Options Exercise For Grant Outstanding Price Balance at January 1, 2018 — 304,850 $ 9.50 Assumed on consummation of Merger 291,102 627,106 $ 26.33 Granted (431,100) 431,100 $ 5.17 Exercised — (2,013) $ 6.49 Forfeited 14,000 (32,403) $ 7.19 Canceled 230,923 (367,752) $ 35.11 $ Balance at September 104,925 960,888 $ 8.82
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Nine Months Ended September 30, 2018 2017 Risk-free interest rate 2.80% 1.87% Expected term 5.96 Years 6.09 Years Expected volatility 79% 91 % Dividend yield 0% 0%
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) (in thousands) Research and development $ 92 $ 69 $ 195 $ 207 General and administrative 91 52 192 167 Total stock-based compensation $ 183 $ 121 $ 387 $ 374

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Net loss $ (6,548) $ (2,173) $ (13,105) $ (8,507) Series B and C preferred dividend — (725) (339) (2,153) Net loss attributable to common stockholders $ (6,548) $ (2,898) $ (13,444) $ (10,660) Shares used to compute net loss per share, basic and diluted 7,141,189 135,658 6,038,001 135,658 Net loss per share attributable to common stockholders, basic and diluted $ (0.92) $ (21.36) $ (2.23) $ (78.58)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Options to purchase common stock 978,495 321,563 802,885 282,515 Warrant to purchase common stock 10,914 — 9,195 — Warrant to purchase convertible preferred stock — 7,563 1,191 7,563 Series B and C convertible preferred stock outstanding, including cumulative dividends — 1,545,224 285,797 1,545,224 Series A convertible preferred stock outstanding — 94,988 16,391 94,988 Convertible promissory notes, related party (as converted) — 731,899 247,557 731,899 Total potentially dilutive securities excluded from denominator of the diluted earnings per share computation 989,409 2,701,237 1,363,016 2,662,189

Organization and Basis of Pre_2

Organization and Basis of Presentation (Details) $ in Thousands	Feb. 13, 2018shares	Sep. 30, 2018USD ($)shares	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Organization and Basis of Presentation (Details) [Line Items]
Stockholders' Equity, Reverse Stock Split	the Company effected a reverse stock split at a ratio of one new share for every eleven shares of the Company’s common stock outstanding
Stock Issued During Period, Shares, Reverse Stock Splits | shares		7,100,000
Exchange Ratio, Number of Shares Exchanged Per Share | shares		0.0201346
Number of Reportable Segments		1
Retained Earnings (Accumulated Deficit) | $		$ (93,087)	$ (79,982)
Cash and Cash Equivalents, at Carrying Value | $		$ 17,922	$ 1,571	$ 1,918	$ 8,405
Private Vaxarts Stockholders Warrantholders And Optionsholders [Member]
Organization and Basis of Presentation (Details) [Line Items]
Equity Method Investment, Ownership Percentage		51.00%
Aviragens Stockholderrs And Optionsholders [Member]
Organization and Basis of Presentation (Details) [Line Items]
Equity Method Investment, Ownership Percentage		49.00%
Oxford Finance [Member]
Organization and Basis of Presentation (Details) [Line Items]
Loan Agreement, Borrowed Amount | $		$ 4,000
Common Stock [Member]
Organization and Basis of Presentation (Details) [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion | shares	0.22148

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Summary of Significant Accounting Policies (Details) [Line Items]
Restricted Cash (in Dollars)	$ 50,000	$ 50,000
Minimum [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year 109 days
Maximum [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	11 years 9 months
Developed Technology Rights [Member] | Minimum [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year 109 days
Developed Technology Rights [Member] | Maximum [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	11 years 9 months
Intellectual Property [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - Estimated Useful Lives	9 Months Ended
	Sep. 30, 2018
Laboratory Equipment [Member]
Summary of Significant Accounting Policies (Details) - Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Lives	5 years
Office Equipment [Member]
Summary of Significant Accounting Policies (Details) - Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Lives	3 years
Leasehold Improvements [Member]
Summary of Significant Accounting Policies (Details) - Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Lives, Description	Shorter of remaining lease term or estimated useful life

Business Combination (Details)

Business Combination (Details) - USD ($) $ in Millions	Feb. 13, 2018	Sep. 30, 2018
Business Combination (Details) [Line Items]
Business Combination, Acquisition Related Costs	$ 1.4	$ 0.5
Maximum [Member]
Business Combination (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life		11 years 9 months
Minimum [Member]
Business Combination (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life		1 year 109 days

Business Combination (Details)

Business Combination (Details) - Total purchase price for Aviragen $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Total purchase price for Aviragen [Abstract]
Common stock	$ 31,789
Total	$ 31,789

Business Combination (Details_2

Business Combination (Details) - Allocation of the purchase price to the fair value of the respective assets and liabilities acquired - USD ($) $ in Thousands	2 Months Ended	3 Months Ended		9 Months Ended
	Feb. 13, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Combination (Details) - Allocation of the purchase price to the fair value of the respective assets and liabilities acquired [Line Items]
Cash and cash equivalents		$ 25,525		$ 25,525
Accounts receivable		14,666		14,666
Prepaid expenses		436		436
Property and equipment		170		170
Developed technology (1)		22,400		22,400
In-process research and development (2)		1,600		1,600
Total assets		64,797		64,797
Accounts payable		(3,304)		(3,304)
Other current liabilities		(6,744)		(6,744)
Liability related to sale of future royalties		(16,300)		(16,300)
Net assets acquired		38,449		38,449
Purchase price				(31,789)
Bargain purchase gain (3)				6,660
Previously Reported [Member]
Business Combination (Details) - Allocation of the purchase price to the fair value of the respective assets and liabilities acquired [Line Items]
Cash and cash equivalents	$ 25,525
Accounts receivable	14,666
Prepaid expenses	446
Property and equipment	170
Developed technology (1)	22,400
In-process research and development (2)	1,600
Total assets	64,807
Accounts payable	(3,379)
Other current liabilities	(6,351)
Liability related to sale of future royalties	(16,300)
Net assets acquired	38,777
Purchase price	(31,789)
Bargain purchase gain (3)	$ 6,988
Restatement Adjustment [Member]
Business Combination (Details) - Allocation of the purchase price to the fair value of the respective assets and liabilities acquired [Line Items]
Cash and cash equivalents
Accounts receivable
Prepaid expenses		(10)		(10)
Property and equipment
Developed technology (1)
In-process research and development (2)
Total assets		(10)		(10)
Accounts payable		75		75
Other current liabilities		(393)		(393)
Liability related to sale of future royalties
Net assets acquired		(328)		$ (328)
Purchase price
Bargain purchase gain (3)		$ (328)

Business Combination (Details_3

Business Combination (Details) - Selected amounts related to Aviragen's business included in the Company's condensed consolidated statement - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Selected amounts related to Aviragen's business included in the Company's condensed consolidated statement [Abstract]
Revenue	$ 87,000	$ 1,068,000
Net loss	$ (2,625)	$ (5,267)

Business Combination (Details_4

Business Combination (Details) - Unaudited pro forma information is summarized - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Unaudited pro forma information is summarized [Abstract]
Total revenue	$ 281	$ 3,586	$ 13,928	$ 12,640
Net loss	$ (6,133)	$ (5,854)	$ (8,385)	$ (23,340)

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - Company's financial assets measured at fair value - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Recurring Financial Assets:
Financial Assets	$ 14	$ 2,607
Fair Value, Inputs, Level 1 [Member]
Recurring Financial Assets:
Financial Assets	14	1,192
Fair Value, Inputs, Level 2 [Member]
Recurring Financial Assets:
Financial Assets		1,415
Fair Value, Inputs, Level 3 [Member]
Recurring Financial Assets:
Financial Assets
Money Market Funds [Member]
Recurring Financial Assets:
Financial Assets	14	1,192
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Recurring Financial Assets:
Financial Assets	14	1,192
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Recurring Financial Assets:
Financial Assets
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Recurring Financial Assets:
Financial Assets
Corporate Bonds [Member]
Recurring Financial Assets:
Financial Assets		1,415
Corporate Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Recurring Financial Assets:
Financial Assets
Corporate Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Recurring Financial Assets:
Financial Assets		1,415
Corporate Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Recurring Financial Assets:
Financial Assets

Fair Value of Financial Instr_4

Fair Value of Financial Instruments (Details) - Company's financial liabilities measured at fair value - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Recurring Financial Liabilities:
Financial Liability		$ 67
Fair Value, Inputs, Level 1 [Member]
Recurring Financial Liabilities:
Financial Liability
Fair Value, Inputs, Level 2 [Member]
Recurring Financial Liabilities:
Financial Liability
Fair Value, Inputs, Level 3 [Member]
Recurring Financial Liabilities:
Financial Liability		67
Convertible Promissory Notes Embedded Derivative Liability [Member]
Recurring Financial Liabilities:
Financial Liability
Convertible Promissory Notes Embedded Derivative Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Recurring Financial Liabilities:
Financial Liability
Convertible Promissory Notes Embedded Derivative Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Recurring Financial Liabilities:
Financial Liability
Convertible Promissory Notes Embedded Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Recurring Financial Liabilities:
Financial Liability
Convertible Preferred Stock Warrant Liability [Member]
Recurring Financial Liabilities:
Financial Liability		67
Convertible Preferred Stock Warrant Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Recurring Financial Liabilities:
Financial Liability
Convertible Preferred Stock Warrant Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Recurring Financial Liabilities:
Financial Liability
Convertible Preferred Stock Warrant Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Recurring Financial Liabilities:
Financial Liability		$ 67

Fair Value of Financial Instr_5

Fair Value of Financial Instruments (Details) - A reconciliation of all liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 67	$ 3,414
Issuances
Revaluation (gains) loss included in (loss) gain on revaluation of financial instruments, net	3	(966)
Settlements	(70)
Balance		2,448
Total gains or loss included in other income and (expenses) attributable to liabilities still held		966
Convertible Preferred Stock Warrant Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	67	134
Issuances
Revaluation (gains) loss included in (loss) gain on revaluation of financial instruments, net	3	(46)
Settlements	(70)
Balance		88
Total gains or loss included in other income and (expenses) attributable to liabilities still held		46
Convertible Promissory Notes Embedded Derivative Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance		3,280
Issuances
Revaluation (gains) loss included in (loss) gain on revaluation of financial instruments, net		(920)
Settlements
Balance		2,360
Total gains or loss included in other income and (expenses) attributable to liabilities still held		$ 920

Balance Sheet Components (Detai

Balance Sheet Components (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disclosure Text Block Supplement [Abstract]
Depreciation	$ 130,000	$ 91,000	$ 349,000	$ 292,000
Impairment of Property And Equipment	106,000		106,000
Amortization of Intangible Assets	812,000	$ 1,000	$ 2,030,000	$ 3,000
Research and Development in Process	$ 1,600,000

Balance Sheet Components (Det_2

Balance Sheet Components (Details) - Cash equivalents and short-term investments - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Balance Sheet Components (Details) - Cash equivalents and short-term investments [Line Items]
Amortized Cost	$ 14	$ 2,607
Gross Unrecognized Gains
Gross Unrecognized Losses
Estimated Fair Value	14	2,607
Carrying Value	14	2,607
Corporate Bonds [Member]
Balance Sheet Components (Details) - Cash equivalents and short-term investments [Line Items]
Amortized Cost		1,415
Gross Unrecognized Gains
Gross Unrecognized Losses
Estimated Fair Value		1,415
Carrying Value		1,415
Short-term Investments [Member]
Balance Sheet Components (Details) - Cash equivalents and short-term investments [Line Items]
Amortized Cost		1,415
Gross Unrecognized Gains
Gross Unrecognized Losses
Estimated Fair Value		1,415
Carrying Value		1,415
Money Market Funds [Member]
Balance Sheet Components (Details) - Cash equivalents and short-term investments [Line Items]
Amortized Cost	14	1,192
Gross Unrecognized Gains
Gross Unrecognized Losses
Estimated Fair Value	14	1,192
Carrying Value	14	1,192
Cash Equivalents [Member]
Balance Sheet Components (Details) - Cash equivalents and short-term investments [Line Items]
Amortized Cost	14	1,192
Gross Unrecognized Gains
Gross Unrecognized Losses
Estimated Fair Value	14	1,192
Carrying Value	$ 14	$ 1,192

Balance Sheet Components (Det_3

Balance Sheet Components (Details) - Accounts receivable net of allowance - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts receivable net of allowance [Abstract]
Royalties receivable	$ 109
Government contract - billed	65	477
Government contract - unbilled	82	153
Accounts receivable, net of allowance	$ 256	$ 630

Balance Sheet Components (Det_4

Balance Sheet Components (Details) - Property and equipment, net - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property and equipment, net [Abstract]
Laboratory equipment	$ 1,993	$ 1,565
Office and computer equipment	256	175
Leasehold improvements	332	226
Total property and equipment	2,581	1,966
Less: accumulated depreciation	(1,522)	(1,236)
Property and equipment, net	$ 1,059	$ 730

Balance Sheet Components (Det_5

Balance Sheet Components (Details) - Intangible assets - USD ($) $ in Thousands	Sep. 30, 2018	Feb. 13, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 22,480	$ 24,080	$ 80
Less accumulated amortization	2,070	40	40
Intangible assets, net	20,410	24,040	40
Purchased Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	22,400	22,400
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross		1,600
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 80	$ 80	$ 80

Balance Sheet Components (Det_6

Balance Sheet Components (Details) - The estimated future amortization expense by year $ in Thousands	Sep. 30, 2018USD ($)
The estimated future amortization expense by year [Abstract]
2018 (three months remaining)	$ 812
2,019	2,254
2,020	1,757
2,021	1,757
2,022	1,757
Thereafter	12,073
Total	$ 20,410

Balance Sheet Components (Det_7

Balance Sheet Components (Details) - Accrued liabilities - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued liabilities [Abstract]
Accrued compensation	$ 1,015	$ 1,320
Accrued clinical and manufacturing expenses	84	69
Accrued professional and consulting services	64	113
Reserve for return of royalties	327
Deferred rent	38	21
Convertible preferred stock warrant liability		67
Other	149	15
Total	$ 1,677	$ 1,605

Revenue (Details)

Revenue (Details) ¥ in Billions	May 25, 2017USD ($)	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2018JPY (¥)	Sep. 30, 2017USD ($)
Entity Loan Modification Program [Member] | HHSBARDA [Member]
Revenue (Details) [Line Items]
Contract with Customer, Liability	$ 14,000,000
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract	1,700,000
Cost of Goods and Services Sold	$ 15,700,000
Contract with Customer, Liability, Revenue Recognized		$ 194,000		$ 915,000	$ 1,324,000		$ 5,079,000
Royalty [Member] | Relenza Recognized [Member]
Revenue (Details) [Line Items]
Revenues		$ 87,000			498,000
Royalty [Member] | Aviragen Therapeutics Inc [Member]
Revenue (Details) [Line Items]
Revenues			$ 5,000,000		$ 5,000,000	¥ 20
Royalty Percentage					4.00%	4.00%
Royalty [Member] | Inavir Recognized [Member]
Revenue (Details) [Line Items]
Revenues					$ 552,000
Royalty [Member] | JAPAN
Revenue (Details) [Line Items]
Revenues					$ 29,000
Royalty Percentage					5.00%	5.00%

Liabilities Related to Sale o_3

Liabilities Related to Sale of Future Royalties (Details) - HCRP [Member] - Royalty Arrangement [Member] $ in Millions	1 Months Ended
	Apr. 30, 2016USD ($)
Liabilities Related to Sale of Future Royalties (Details) [Line Items]
Debt, Additions	$ 20
HCRP Agreement, Revenue Terms	HCRP is entitled to the first $3.0 million plus 15% of the next $1.0 million in royalties earned in each year commencing on April 1
Revenues	$ 3
Royalty Percentage	15.00%
Royalty Income, Nonoperating	$ 1

Liabilities Related to Sale o_4

Liabilities Related to Sale of Future Royalties (Details) - Liability related to sale of future Royalties $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Liability related to sale of future Royalties [Abstract]
Total Liability related to sale of future royalties, February 13, 2018	$ 16,300
Non-cash royalty revenue paid to HCRP	(18)
Non-cash interest expense recognized	1,298
TotalLiability related to sale of future royalties, September 30, 2018	$ 17,580

Convertible Promissory Notes,_2

Convertible Promissory Notes, Related Parties (Details) - USD ($)	Feb. 13, 2018	Nov. 20, 2015	Dec. 10, 2014	Sep. 30, 2018	Dec. 31, 2017
Convertible Promissory Notes, Related Parties (Details) [Line Items]
Proceeds from Convertible Debt				$ 25,000,000
Debt Instrument, Interest Rate, Stated Percentage				8.00%
Debt Instrument, Increase, Accrued Interest					$ 6,300,000
Debt Instrument, Unamortized Discount					$ 400,000
Debt Conversion, Converted Instrument, Shares Issued (in Shares)	1,571,702
Debt Instrument, Convertible, Conversion Price (in Dollars per share)	$ 9.05
Debt Conversion, Converted Instrument, Amount	$ 14,200,000
Other Ownership Interests, Contributed Capital	21,400,000
Note Purchase Agreement [Member]
Convertible Promissory Notes, Related Parties (Details) [Line Items]
Proceeds from Convertible Debt			$ 18,400,000
Second Note Purchase Agreement [Member]
Convertible Promissory Notes, Related Parties (Details) [Line Items]
Proceeds from Convertible Debt		$ 11,000,000
Convertible Promissory Notes [Member]
Convertible Promissory Notes, Related Parties (Details) [Line Items]
Debt Instrument, Unamortized Discount	400,000
Debt Instrument, Face Amount	35,600,000
Debt Instrument, Periodic Payment, Interest	6,600,000
Debt Instrument, Periodic Payment, Principal	$ 29,400,000
Notes Issued In 2014 [Member]
Convertible Promissory Notes, Related Parties (Details) [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability				$ 1,900,000
Debt Issuance Costs, Net				20,000
Notes Issued In 2015 [Member]
Convertible Promissory Notes, Related Parties (Details) [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability				1,300,000
Debt Issuance Costs, Net				$ 7,000

Secured Promissory Note Payab_2

Secured Promissory Note Payable to Oxford Finance (Details) - Loan Agreement [Member] - Oxford Finance [Member] - USD ($)	Dec. 22, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Secured Promissory Note Payable to Oxford Finance (Details) [Line Items]
Long-term Debt, Gross	$ 5,000,000
Debt Instrument, Payment Terms	a secured promissory note and is repayable over four years, with interest only payable over the first 12 months and the balance fully amortized over the subsequent 36 months.
Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid		$ 325,000		$ 325,000
Interest Expense, Debt		114,000	$ 131,000	366,000	$ 386,000
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		$ 87,000	$ 93,000	276,000	$ 241,000
Debt Conversion, Converted Instrument, Amount				$ 250,000
Convertible Preferred Stock [Member] | Series C Preferred Stock [Member]
Secured Promissory Note Payable to Oxford Finance (Details) [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in Shares)		7,563		7,563
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per share)		$ 33.11		$ 33.11
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 134,000		$ 134,000
Debt Instrument, Interest Rate, Stated Percentage		10.50%		10.50%
London Interbank Offered Rate (LIBOR) [Member]
Secured Promissory Note Payable to Oxford Finance (Details) [Line Items]
Debt Instrument, Description of Variable Rate Basis	30-day U.S. LIBOR plus 6.17%
Debt Instrument, Basis Spread on Variable Rate	6.17%
Warrant [Member] | Common Stock [Member]
Secured Promissory Note Payable to Oxford Finance (Details) [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per share)		$ 22.99		$ 22.99
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 70,000		$ 70,000
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in Shares)		10,914		10,914
Debt Conversion, Converted Instrument, Issuance Date				Feb. 13, 2018

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($)	3 Months Ended	9 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017
Commitments and Contingencies (Details) [Line Items]
Operating Leases, Rent Expense		$ 623,000	$ 456,000
Office Space In Alpharetta Georgia [Member]
Commitments and Contingencies (Details) [Line Items]
Lease Expiration Date		Feb. 28, 2021
Subsequent Event [Member]
Commitments and Contingencies (Details) [Line Items]
Operating Lease, Impairment Loss	$ 200,000
The First Lease [Member] | Office Space In San Francisco California [Member]
Commitments and Contingencies (Details) [Line Items]
Lease Expiration Date		Apr. 30, 2020
Remaining Four Leases [Member] | Minimum [Member] | Office Space In San Francisco California [Member]
Commitments and Contingencies (Details) [Line Items]
Lease Expiration Date		Dec. 31, 2018
Remaining Four Leases [Member] | Maximum [Member] | Office Space In San Francisco California [Member]
Commitments and Contingencies (Details) [Line Items]
Lease Expiration Date		Aug. 31, 2019

Commitments and Contingencies_3

Commitments and Contingencies (Details) - The future minimum lease payments $ in Thousands	Sep. 30, 2018USD ($)
The future minimum lease payments [Abstract]
2018 (three months remaining)	$ 271
2,019	781
2,020	411
2,021	56
Thereafter
Total	$ 1,519

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 13, 2018	Dec. 31, 2017	Sep. 30, 2018
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Authorized (in Shares)		5,000,000	5,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.10	$ 0.10
Preferred Stock, Shares Outstanding (in Shares)		1,221,064	0
Convertible Preferred Stock, Terms of Conversion			At the option of the holder, each share of convertible preferred stock was convertible, one‑for‑one, subject to adjustment for anti‑dilution protection, into shares of common stock. Each share automatically converted into the number of shares of common stock into which the shares were convertible at the then applicable conversion ratio upon: (1) the closing of the sale of the Company’s common stock in a public offering provided the offering price per share was not less than three times the Series C convertible preferred stock original issue price of $33.05196 and the aggregate gross proceeds were not less than $30.0 million, or (2) upon receipt of a written consent of the holders of a majority of the then outstanding shares of convertible preferred stock voting as a single class on an as‑converted basis
Convertible Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Authorized (in Shares)		1,662,171
Preferred Stock, Shares Outstanding (in Shares)		1,221,064
Preferred Stock, Voting Rights			The holders of convertible preferred stock were entitled to the number of votes equal to the number of shares of common stock into which each share of Series A, Series B, and Series C convertible preferred stock could have been converted on the record date for the vote or consent of the stockholders, except as otherwise required by law, and had voting rights and powers equal to the voting rights and powers of the common stockholders. The holders of Series A convertible preferred stock, voting as a separate class, were entitled to elect one member of the board of directors. As long as a specified investor held at least one share of Series C convertible preferred stock, the specified investor was able to designate one member of the board of directors, who would have been elected by the holders of Series C convertible preferred stock voting as a separate class. As long as a specified investor held least one share of Series B convertible preferred stock, the specified investor was able to designate one member of the board of directors, who would have been elected by the holders of Series B convertible preferred stock voting as a separate class. The holders of common stock, voting as a separate class, were entitled to elect two members of the board of directors, one of whom was the duly appointed chief executive officer of the Company
Convertible Preferred Stock [Member] | Series C Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Authorized (in Shares)		820,088
Preferred Stock, Dividend Rate, Per-Dollar-Amount			$ 2.64416
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears			33.05196
Dividends, Preferred Stock (in Dollars)	$ 7.3	$ 7.1
Preferred Stock, Dividends Per Share, Declared	$ 12.06	$ 11.74
Preferred Stock, Shares Outstanding (in Shares)		605,103
Shares Issued, Price Per Share			33.05196
Preferred Stock, Liquidation Preference Per Share			$ 33.05196
Convertible Preferred Stock [Member] | Series C Preferred Stock [Member] | Minimum [Member]
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Outstanding (in Shares)			20,134
Proceeds from Issuance of Convertible Preferred Stock (in Dollars)			$ 30
Convertible Preferred Stock [Member] | Series B Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Authorized (in Shares)		747,095
Preferred Stock, Dividend Rate, Per-Dollar-Amount			$ 2.64416
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 15.78		33.05196
Dividends, Preferred Stock (in Dollars)	$ 7.6	$ 7.5
Preferred Stock, Dividends Per Share, Declared		$ 15.46
Preferred Stock, Shares Outstanding (in Shares)	483,387	520,973
Preferred Stock, Liquidation Preference Per Share			$ 33.05196
Convertible Preferred Stock [Member] | Series B Preferred Stock [Member] | Minimum [Member]
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Outstanding (in Shares)			20,134
Convertible Preferred Stock [Member] | Series A Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Authorized (in Shares)		94,988
Preferred Stock, Dividend Rate, Per-Dollar-Amount			$ 2.30449
Preferred Stock, Shares Outstanding (in Shares)		94,988
Preferred Stock, Liquidation Preference Per Share			$ 28.80613
Common Stock [Member]
Stockholders' Equity (Details) [Line Items]
Stock Issued During Period, Shares, Acquisitions (in Shares)			3,510,439
Common Stock, Voting Rights			Holders of common stock are entitled to one vote per share on matters to be voted on by stockholders
Common Stock [Member] | Convertible Preferred Stock [Member] | Series C Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Stock Issued During Period, Shares, Acquisitions (in Shares)	696,028
Common Stock [Member] | Convertible Preferred Stock [Member] | Series C Preferred Stock [Member] | Dividend Paid [Member]
Stockholders' Equity (Details) [Line Items]
Stock Issued During Period, Shares, Acquisitions (in Shares)	253,851
Common Stock [Member] | Convertible Preferred Stock [Member] | Series B Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Stock Issued During Period, Shares, Acquisitions (in Shares)	599,259
Common Stock [Member] | Convertible Preferred Stock [Member] | Series B Preferred Stock [Member] | Dividend Paid [Member]
Stockholders' Equity (Details) [Line Items]
Stock Issued During Period, Shares, Acquisitions (in Shares)	265,340
Common Stock [Member] | Convertible Preferred Stock [Member] | Series A Preferred Stock [Member]
Stockholders' Equity (Details) [Line Items]
Stock Issued During Period, Shares, Acquisitions (in Shares)	104,065

Stockholders' Equity (Details)

Stockholders' Equity (Details) - Convertible preferred stock - Convertible Preferred Stock [Member] - USD ($) $ in Thousands	Feb. 13, 2018	Dec. 31, 2017
Stockholders' Equity (Details) - Convertible preferred stock [Line Items]
Preferred stock, shares authorized		1,662,171
Preferred stock, shares outstanding		1,221,064
Preferred stock, net carrying value		$ 38,941
Preferred stock, liquidation preference		$ 39,956
Series A Preferred Stock [Member]
Stockholders' Equity (Details) - Convertible preferred stock [Line Items]
Preferred stock, shares authorized		94,988
Preferred stock, shares outstanding		94,988
Preferred stock, net carrying value		$ 2,949
Preferred stock, liquidation preference		$ 2,737
Series B Preferred Stock [Member]
Stockholders' Equity (Details) - Convertible preferred stock [Line Items]
Preferred stock, shares authorized		747,095
Preferred stock, shares outstanding	483,387	520,973
Preferred stock, net carrying value		$ 16,115
Preferred stock, liquidation preference		$ 17,219
Series C Preferred Stock [Member]
Stockholders' Equity (Details) - Convertible preferred stock [Line Items]
Preferred stock, shares authorized		820,088
Preferred stock, shares outstanding		605,103
Preferred stock, net carrying value		$ 19,877
Preferred stock, liquidation preference		$ 20,000

Stockholders' Equity (Details_2

Stockholders' Equity (Details) - Common stock reserved for issuance - shares	Sep. 30, 2018	Dec. 31, 2017
Stockholders' Equity (Details) - Common stock reserved for issuance [Line Items]
Common stock reserved for issuance	1,099,454	1,977,924
Convertible Preferred Stock Outstanding [Member]
Stockholders' Equity (Details) - Common stock reserved for issuance [Line Items]
Common stock reserved for issuance		1,221,064
Options Issued And Outstanding [Member]
Stockholders' Equity (Details) - Common stock reserved for issuance [Line Items]
Common stock reserved for issuance	960,888	304,850
Options Available For Future Grants [Member]
Stockholders' Equity (Details) - Common stock reserved for issuance [Line Items]
Common stock reserved for issuance	127,652
Cumulative Convertible Preferred Stock Dividends [Member]
Stockholders' Equity (Details) - Common stock reserved for issuance [Line Items]
Common stock reserved for issuance		441,096
Common Stock Warrants [Member]
Stockholders' Equity (Details) - Common stock reserved for issuance [Line Items]
Common stock reserved for issuance	10,914	10,914

Equity Incentive Plans (Details

Equity Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Employee Stock Option [Member]
Equity Incentive Plans (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 3.59	$ 2.99
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 1.3
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 350 days
Restricted Stock [Member]
Equity Incentive Plans (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	22,727
Maximum [Member] | Employee Stock Option [Member]
Equity Incentive Plans (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	10 years

Equity Incentive Plans (Detai_2

Equity Incentive Plans (Details) - Summary of stock option	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Summary of stock option [Abstract]
Balance at January 1, 2018
Balance at January 1, 2018	304,850
Balance at January 1, 2018 (in Dollars per share) | $ / shares	$ 9.50
Assumed on consummation of Merger	291,102
Assumed on consummation of Merger	627,106
Assumed on consummation of Merger (in Dollars per share) | $ / shares	$ 26.33
Granted	(431,100)
Granted	431,100
Granted (in Dollars per share) | $ / shares	$ 5.17
Exercised	(2,013)
Exercised (in Dollars per share) | $ / shares	$ 6.49
Forfeited	14,000
Forfeited	(32,403)
Forfeited (in Dollars per share) | $ / shares	$ 7.19
Canceled	230,923
Canceled	(367,752)
Canceled (in Dollars per share) | $ / shares	$ 35.11
Balance at September 30, 2018	104,925
Balance at September 30, 2018	960,888
Balance at September 30, 2018 (in Dollars per share) | $ / shares	$ 8.82

Equity Incentive Plans (Detai_3

Equity Incentive Plans (Details) - Fair values estimated assumptions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Fair values estimated assumptions [Abstract]
Risk-free interest rate	2.80%	1.87%
Expected term	5 years 350 days	6 years 32 days
Expected volatility	79.00%	91.00%
Dividend yield	0.00%	0.00%

Equity Incentive Plans (Detai_4

Equity Incentive Plans (Details) - Total stock-based compensation recognized for options - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 183	$ 121	$ 387	$ 374
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	92	69	195	207
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 91	$ 52	$ 192	$ 167

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders (Details) - Calculation of basic and diluted net income (loss) per share - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Loss Per Share Attributable to Common Stockholders (Details) - Calculation of basic and diluted net income (loss) per share [Line Items]
Net loss	$ (6,548)	$ (2,173)	$ (13,105)	$ (8,507)
Net loss attributable to common stockholders	$ (6,548)	$ (2,898)	$ (13,444)	$ (10,660)
Shares used to compute net loss per share, basic and diluted (in Shares)	7,141,189	135,658	6,038,001	135,658
Net loss per share attributable to common stockholders, basic and diluted (in Dollars per share)	$ (0.92)	$ (21.36)	$ (2.23)	$ (78.58)
Series B And C Preferred Stock [Member]
Net Loss Per Share Attributable to Common Stockholders (Details) - Calculation of basic and diluted net income (loss) per share [Line Items]
Series B and C preferred dividend		$ (725)	$ (339)	$ (2,153)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders (Details) - Potentially dilutive securities excluded from the computation of diluted weighted average shares - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation	989,409	2,701,237	1,363,016	2,662,189
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation	978,495	321,563	802,885	282,515
Warrant [Member] | Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation	10,914		9,195
Warrant [Member] | Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation		7,563	1,191	7,563
Cumulative Convertible Preferred Stock Dividends [Member] | Series B And C Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation		1,545,224	285,797	1,545,224
Convertible Preferred Stock Outstanding [Member] | Series A Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation		94,988	16,391	94,988
Convertible Promissory Notes Related Party [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation		731,899	247,557	731,899