NVN Liquidation (NOVNQ) 10-Q 15 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 06, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	NOVN
Entity Registrant Name	NOVAN, INC.
Entity Central Index Key	0001467154
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding (in shares)		26,069,734

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 6,077	$ 8,194
Deferred offering costs	49	49
Prepaid expenses and other current assets	1,062	1,107
Total current assets	7,188	9,350
Restricted cash	539	539
Intangible assets	75	75
Other assets	501	530
Property and equipment, net	11,657	15,868
Right-of-use lease assets	1,833	0
Total assets	21,793	26,362
Current liabilities:
Accounts payable	1,510	1,250
Accrued compensation	2,082	1,467
Accrued outside research and development services	817	563
Accrued legal and professional fees	258	498
Other accrued expenses	516	871
Deferred revenue, current portion	4,401	4,401
Lease liabilities, current portion	1,139	11
Total current liabilities	10,723	9,061
Deferred revenue, net of current portion	5,926	2,566
Lease liabilities, net of current portion	5,544	10
Warrant liability	1,628	1,240
Other long-term liabilities	335	289
Facility financing obligation	0	7,998
Total liabilities	24,156	21,164
Commitments and contingencies (Notes 3, 4, 7, 10 and 11)
Stockholders’ (deficit) equity
Common stock $0.0001 par value; 200,000,000 shares authorized as of March 31, 2019 and December 31, 2018; 26,079,234 and 26,066,235 shares issued as of March 31, 2019 and December 31, 2018, respectively; 26,069,734 and 26,056,735 shares outstanding as of March 31, 2019 and December 31, 2018, respectively	3	3
Additional paid-in capital	177,855	177,677
Treasury stock at cost, 9,500 shares as of March 31, 2019 and December 31, 2018	(155)	(155)
Accumulated deficit	(180,066)	(172,327)
Total stockholders’ (deficit) equity	(2,363)	5,198
Total liabilities and stockholders’ (deficit) equity	$ 21,793	$ 26,362

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	26,079,234	26,066,235
Common stock, shares outstanding (in shares)	26,069,734	26,056,735
Treasury stock (in shares)	9,500	9,500

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Total revenue	$ 1,100	$ 658
Operating expenses:
Research and development	4,827	6,335
General and administrative	2,994	2,880
Total operating expenses	7,821	9,215
Operating loss	(6,721)	(8,557)
Other (expense) income, net:
Interest income	28	44
Interest expense	0	(262)
Change in fair value of warrant liability	(388)	3,558
Other income, net	56	0
Total other (expense) income, net	(304)	3,340
Net loss	(7,025)	(5,217)
Comprehensive loss	$ (7,025)	$ (5,217)
Net loss per share, basic and diluted (in USD per share)	$ (0.27)	$ (0.21)
Weighted-average common shares outstanding, basic and diluted (in shares)	26,066,064	25,026,890
License and collaboration revenue
Total revenue	$ 1,100	$ 649
Research and development services revenue
Total revenue	$ 0	$ 9

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' (Deficit) Equity) (unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit
Beginning balance, shares (in shares) at Dec. 31, 2017		16,005,408
Beginning balance at Dec. 31, 2017	$ (1,716)	$ 2	$ 158,091	$ (155)	$ (159,654)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	887		887
Exercise of stock options (in shares)		33,334
Exercise of stock options	37		37
Net loss	(5,217)				(5,217)
Common stock issued through public offering, net of underwriting discounts, warrants, commissions and offering costs (Note 1) (in shares)		10,000,000
Common stock issued through public offering, net of underwriting discounts, warrants, commissions and offering costs (Note 1)	17,388	$ 1	17,387
Ending balance, in shares (in shares) at Mar. 31, 2018		26,038,742
Ending balance at Mar. 31, 2018	11,379	$ 3	176,402	(155)	(164,871)
Beginning balance, shares (in shares) at Dec. 31, 2018		26,056,735
Beginning balance at Dec. 31, 2018	5,198	$ 3	177,677	(155)	(172,327)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	$ 168		168
Exercise of stock options (in shares)	12,999	12,999
Exercise of stock options	$ 10		10
Net loss	(7,025)				(7,025)
Ending balance, in shares (in shares) at Mar. 31, 2019		26,069,734
Ending balance at Mar. 31, 2019	(2,363)	$ 3	$ 177,855	$ (155)	(180,066)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards (Note 1)	$ (714)				$ (714)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flow from operating activities:
Net loss	$ (7,025)	$ (5,217)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	503	401
Share-based compensation	214	887
Change in fair value of warrant liability	388	(3,558)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	45	(6)
Accounts payable	242	353
Accrued compensation	615	(1,191)
Accrued outside research and development services	254	(134)
Accrued legal and professional fees	(199)	67
Other accrued expenses	(406)	(621)
Deferred revenue	3,360	(645)
Other long-term assets	(101)	16
Net cash used in operating activities	(2,110)	(9,648)
Cash flow from investing activities:
Purchases of property and equipment	(17)	(140)
Proceeds from the sale of property and equipment	0	0
Net cash used in investing activities	(17)	(140)
Cash flow from financing activities:
Proceeds from public offering, net of underwriting fees and commissions	0	35,625
Payments related to public offering costs	0	(296)
Proceeds from exercise of stock options	10	37
Payments on capital lease obligation	0	(2)
Net cash provided by financing activities	10	35,364
Net (decrease) increase in cash, cash equivalents and restricted cash	(2,117)	25,576
Cash, cash equivalents and restricted cash as of beginning of period	8,733	3,063
Cash, cash equivalents and restricted cash as of end of period	6,616	28,639
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment with accounts payable and accrued expenses	69	191
Non-cash addition to deferred offering costs	0	25
Deferred offering costs reclassified to additional paid-in capital	0	431
Reconciliation to condensed consolidated balance sheets:
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 8,733	$ 3,063

Organization and Significant Ac

Organization and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Organization and Significant Accounting Policies	Organization and Significant Accounting Policies Business Description and Basis of Presentation Novan, Inc. (“Novan” and together with its subsidiaries, the “Company”), is a North Carolina-based clinical development-stage biotechnology company focused on leveraging nitric oxide’s naturally occurring anti-microbial and immunomodulatory mechanisms of action to treat a range of diseases with significant unmet needs. Novan was incorporated in January 2006 under the state laws of Delaware. The wholly-owned subsidiary, Novan Therapeutics, LLC was organized in 2015 under the state laws of North Carolina. On March 14, 2019, the Company completed registration of a wholly-owned Ireland-based subsidiary, Novan Therapeutics, Limited. The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The December 31, 2018 year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. Additionally, the Company’s independent registered public accounting firm report for the December 31, 2018 financial statements included an explanatory paragraph indicating that there is substantial doubt about the Company’s ability to continue as a going concern. Basis of Consolidation The accompanying condensed consolidated financial statements reflect the operations of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Liquidity and Ability to Continue as a Going Concern The Company’s condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The accompanying condensed consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from uncertainty related to the Company’s ability to continue as a going concern. The Company has evaluated principal conditions and events that may raise substantial doubt about its ability to continue as a going concern within one year from the date that these financial statements are issued. The Company identified the following conditions: • The Company has reported a net loss in all fiscal periods since inception and, as of March 31, 2019 , the Company had an accumulated deficit of $ 180,066 . • As described in Note 13—Subsequent Events, in April 2019 and May 2019 the Company entered into (i) a royalty and milestone payments purchase agreement with a stockholder providing $25,000 of immediate funding, with an additional $10,000 contingent upon achieving successful top-line results of the SB206 Phase 3 clinical trials no later than March 31, 2020; and (ii) a development funding and royalties agreement with a corporate partner providing $12,000 of immediate funding. The Company believes that its existing cash and cash equivalents, expected contractual payments to be received in connection with previous licensing agreements, and the addition of the $25,000 and $12,000 received through these funding transactions will (i) provide the Company with adequate liquidity to fund its planned operating needs into the first quarter of 2020, including through expected top-line results of the Phase 3 molluscum clinical program targeted in the first quarter of 2020, or before; and (ii) into the second quarter of 2020, if paired with the potential $10,000 funding contingent upon achieving successful top-line results of the SB206 Phase 3 clinical trials no later than March 31, 2020. As of May 7, 2019, the total of $37,000 of immediate funds related to these two agreements had been received by the Company. • The Company’s primary use of cash is to fund its operating expenses, which consist principally of research and development expenditures necessary to advance its product candidates. The Company has evaluated its expected, probable future cash flow needs and has determined that it expects to incur substantial losses in the future as it conducts planned operating activities. As such, the Company has concluded that the prevailing conditions and ongoing liquidity risks it faces raise substantial doubt about its ability to continue as a going concern. The Company will need substantial additional funding to continue its operating activities and make further advancements in its drug development programs beyond those planned in 2019 and certain activities in the first half of 2020. The failure of the Company to obtain sufficient funds on acceptable terms, or the failure to trigger the $10,000 contingent payment under the Company’s royalty and milestone payments purchase agreement, could have a material adverse effect on the Company’s business and cause the Company to alter or reduce its planned operating activities, including but not limited to delaying, reducing, terminating or eliminating planned product candidate development activities, to conserve its cash and cash equivalents. The Company intends to secure additional capital as needed from non-dilutive sources, including partnerships, collaborations, licensing, grants or other strategic relationships, or through equity or debt financings, which could result in dilution. January 2018 Offering On January 9, 2018, the Company completed a public offering of its common stock and warrants pursuant to the Company’s effective shelf registration statement (the “January 2018 Offering”). The Company sold an aggregate of 10,000,000 shares of common stock and warrants to purchase up to 10,000,000 shares of the Company’s common stock at a public offering price of $3.80 per share of common stock and accompanying warrant. The warrant exercise price is $4.66 per share and will expire four years from the date of issuance. Net proceeds from the offering were approximately $35,194 after deducting underwriting discounts and commissions and offering expenses of approximately $2,806 . The Company incurred costs directly related to (i) the shelf registration statement filing totaling $110 and (ii) the January 2018 Offering completed in January 2018 totaling $370 , all of which were initially capitalized and included in deferred offering costs. A pro-rata portion of the shelf registration offering costs and all of the January 2018 Offering costs were reclassified to additional paid-in capital upon completion of the January 2018 Offering. 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 and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from these estimates. Unaudited Interim Condensed Consolidated Financial Statements The accompanying interim condensed consolidated financial statements and the related footnote disclosures are unaudited. These unaudited condensed consolidated financial statements have been prepared in accordance with U.S. GAAP and applicable rules and regulations of the Securities and Exchange Commission’s (“SEC”) Rule 10-01 of Regulation S-X for interim financial information. The condensed consolidated financial statements were prepared on the same basis as the audited consolidated financial statements and in the opinion of management, reflect all adjustments of a normal, recurring nature that are necessary for the fair statement of the Company’s financial position and its results of operations and cash flows. The results of operations for interim periods are not necessarily indicative of the results expected for the full fiscal year or any future period. These interim financial statements should be read in conjunction with the financial statements and notes for the year ended December 31, 2018 set forth in the Company’s Annual Report on Form 10-K filed with the SEC on March 27, 2019 . Restricted Cash Restricted cash of $539 as of March 31, 2019 and December 31, 2018 , consisted of funds maintained in a separate deposit account to secure a letter of credit for the benefit of the lessor of facility space leased by the Company. Leases The Company’s significant accounting policies regarding leases are described in Note 1 of the Notes to the Consolidated Financial Statements included in its Annual Report on Form 10-K for the year ended December 31, 2018. Updates to the Company’s accounting policies, including impacts from the adoption of new accounting standards, are discussed within the section below, “Accounting Pronouncements Adopted” , and within Note 7—Commitments and Contingencies. Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted average shares outstanding during the period, without consideration of common stock equivalents. Diluted net loss per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are anti-dilutive for all periods presented. The following securities, presented on a common stock equivalent basis, have been excluded from the calculation of weighted average common shares outstanding for the three months ended March 31, 2019 and 2018 because the effect is anti-dilutive due to the net loss reported in each of those periods. All share amounts presented in the table below represent the total number outstanding as of the end of each period. In addition, as described in Note 10—Share-Based Compensation, the Company’s board granted 1,000,000 stock appreciation rights (“SARs”) on a contingent basis in the third quarter of 2018. These securities are subject to stockholder approval and therefore are not considered outstanding as of March 31, 2019; however, if such securities were to be approved by stockholders, their effect would be anti-dilutive. March 31, 2019 2018 Warrants to purchase common stock associated with January 2018 public offering (Note 9) 10,000,000 10,000,000 Stock options outstanding under the 2008 and 2016 Plans (Note 10) 1,544,857 1,560,134 Inducement options outstanding (Note 10) 100,500 — Segment and Geographic Information The Company has determined that it operates in one segment. The Company uses its nitric oxide-based technology to develop product candidates. The Chief Executive Officer, who is the Company’s chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. The Company has only had limited revenue since its inception, but all revenue was derived from licensing agreements originating in the United States. All of the Company’s long-lived assets are maintained in the United States. Although all operations are based in the United States, the Company generated revenue from its licensing partner in Japan of $1,100 and $649 during the three months ended March 31, 2019 and 2018 , respectively. During the three months ended March 31, 2019 and 2018 , substantially all revenue was generated from the Company’s licensing partner in Japan. Recently Issued Accounting Standards Accounting Pronouncements Adopted In February 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) . This guidance revises the accounting related to leases by requiring lessees to recognize a lease liability and a right-of-use asset for all leases. The new lease guidance also simplifies the accounting for sale and leaseback transactions. In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases and ASU 2018-11, Leases (Topic 842): Targeted Improvements, and in March 2019, the FASB issued ASU 2019-01, Leases (Topic 842): Codification Improvements. These additional ASUs were issued to provide expanded or clarifying guidance associated with the application of certain principles . Under the guidance, lessees are required to recognize assets and lease liabilities on the balance sheet for most leases including operating leases and provide enhanced disclosures. There are optional practical expedients that a company may elect to apply. The guidance was effective for the Company beginning in its first quarter of 2019. The Company adopted Topic 842 as of January 1, 2019 using the modified alternative retrospective transition method and initially applied the transition provisions as of January 1, 2019. This transition method allowed the Company to continue to apply the legacy guidance in ASC 840 for periods prior to 2019 and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit as of the date of adoption. The Company elected the package of transition practical expedients, which, among other things, allowed the Company to keep the historical lease classifications and not have to reassess the lease classification and initial direct costs for any existing or expired leases as of the date of adoption. The Company also made an accounting policy election to apply the short-term lease exception, which allows the Company to exclude leases with an initial term of twelve months or less from the consolidated balance sheets. Lease expense for leases with an initial term of twelve months or less will be recognized over the lease term, similar to the accounting treatment under ASC 840. As a result of the adoption of Topic 842, the Company derecognized $10,557 of building assets (property, plant and equipment), and the $7,998 facility financing obligation associated with the previously existing build-to-suit arrangement related to its sole corporate and manufacturing facility. The Company also capitalized leasehold improvements and ROU assets of $5,885 and $1,827 , respectively, and recorded lease liabilities for operating leases totaling $6,786 , as of January 1, 2019. The capitalized leasehold improvement assets recorded as part of the adoption of Topic 842 were previously included within the derecognized building asset as part of the previous build-to-suit arrangement. The Company also recognized an increase of $714 to accumulated deficit related to its de-recognition of its previously recorded build-to-suit arrangement. The impact of the adoption of this guidance is non-cash in nature and did not affect the Company’s cash flows. See Note 7—Commitments and Contingencies, for additional information related to the adoption of Topic 842. In June 2018, the FASB issued ASU No. 2018-07 Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting . This guidance simplifies the accounting for non-employee share-based payment transactions by expanding the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. Under the new standard, most of the guidance on stock compensation payments to non-employees would be aligned with the requirements for share-based payments granted to employees. This standard is effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within those annual reporting periods, with early adoption permitted. This ASU was effective for the Company as of January 1, 2019. The adoption of this new accounting guidance did not have a material impact on the Company’s condensed consolidated financial statements. Accounting Pronouncements Being Evaluated In August 2018, the FASB issued ASU No. 2018-13 Fair Value Measurement (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement. This guidance is intended to improve the effectiveness of disclosure requirements on fair value measurements in Topic 820. The new standard modifies certain disclosure requirements and will be effective for annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact of adoption of this ASU and does not expect the adoption of this new standard to have a material impact on its condensed consolidated financial statements. In October 2018, the FASB issued ASU No. 2018-17 Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. This guidance is intended to improve the accounting for variable interest entities and whether the entity should be consolidated. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim reporting periods within those annual reporting periods, with early adoption permitted. The Company is evaluating the impact of adoption of this ASU and does not currently expect the adoption of this new standard to have a material impact on its condensed consolidated financial statements.

KNOW Bio, LLC

KNOW Bio, LLC	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
KNOW Bio, LLC	KNOW Bio, LLC On December 30, 2015, the Company completed the distribution of 100% of the outstanding member interests of KNOW Bio, LLC (“KNOW Bio”), a former wholly owned subsidiary of the Company, to Novan’s stockholders (the “Distribution”), pursuant to which KNOW Bio became an independent privately held company. KNOW Bio is an independent, privately held company with a portfolio of operating subsidiaries that are advancing nitric oxide-based therapies using technology that is proprietary and/or in fields where they have exclusive intellectual property rights. The Company does not own any equity interest in KNOW Bio, has no common management or board representation at KNOW Bio, and the contractual arrangements between the two entities do not provide the Company with decision-making authority or power to influence KNOW Bio’s drug and medical device development activities. The Company conducted an initial assessment of KNOW Bio under the variable interest consolidation model pursuant to FASB ASC 810, Consolidation , at the time of the Distribution in 2015 and has monitored KNOW Bio during each subsequent reporting period, including two required ASC 810 reassessments performed during 2017. The Company has consistently determined that KNOW Bio should not be consolidated in its consolidated financial statements. In the fourth quarter of 2018, KNOW Bio and its operating subsidiaries received significant additional equity investments that enable progression of their technology. These events required the Company to conduct another reassessment of variable interest entity characteristics, pursuant to FASB ASC 810-10, Consolidation , in which it determined that KNOW Bio should not be consolidated in its consolidated financial statements. KNOW Bio Technology Agreements In connection with the Distribution, the Company entered into exclusive license agreements and sublicense agreements with KNOW Bio, as described below. The agreements will continue for so long as there is a valid patent claim under the respective agreement, unless earlier terminated, and upon expiration, will continue as perpetual non-exclusive licenses. KNOW Bio has the right to terminate each such agreement, for any reason upon 90 days advance written notice to the Company. License of existing and potential future intellectual property to KNOW Bio. The Company granted to KNOW Bio exclusive licenses, with the right to sublicense, to certain U.S. and foreign patents and patent applications controlled by the Company as of December 29, 2015 (the “KNOW Bio License Agreement”). The Company also granted to KNOW Bio an exclusive license, with the right to sublicense, to any patents and patent applications that became controlled by the Company during the three -year period between the agreement’s effective date and December 29, 2018 related to nitric oxide-releasing compositions and methods of manufacturing thereof, including methods of manufacturing Nitricil compounds and other nitric oxide-based therapeutics. Sublicense of UNC and other third party intellectual property to KNOW Bio. The Company also granted to KNOW Bio exclusive sublicenses, with the ability to further sublicense, under certain of the U.S. and foreign patents and patent applications exclusively licensed to the Company from UNC (the “UNC License Agreement”) and another third party directed towards nitric oxide-releasing compositions, to develop and commercialize products utilizing the licensed technology (the “KNOW Bio Sublicense Agreements”). Under the exclusive sublicense to the UNC patents and applications (the “UNC Sublicense Agreement”), KNOW Bio is subject to the terms and conditions under the UNC License Agreement, including milestone and diligence payment obligations. However, pursuant to the terms of the UNC License Agreement, the Company is directly obligated to pay UNC any future milestones or royalties, including those resulting from actions conducted by the Company’s sublicensees, including KNOW Bio. Therefore, in the event of KNOW Bio non-performance with respect to its obligations under the UNC Sublicense Agreement, the Company would be obligated to make such payments to UNC. KNOW Bio would then become obligated to repay the Company pursuant to the UNC Sublicense Agreement, otherwise KNOW Bio would be in breach of its agreements with the Company and intellectual property rights would revert back to the Company. There were no milestone or royalty payments required during the three months ended March 31, 2019 and 2018 . Amendments to License and Sublicense Agreements with KNOW Bio The Company and KNOW Bio entered into certain amendments dated October 13, 2017 (the “KNOW Bio Amendments”) to the KNOW Bio License Agreement and KNOW Bio Sublicense Agreements (the “Original KNOW Bio Agreements”) described above. Pursuant to the terms of the KNOW Bio Amendments, the Company re-acquired from KNOW Bio exclusive, worldwide rights under certain U.S. and foreign patents and patent applications controlled by the Company as of the execution date of the Original KNOW Bio Agreements, and patents and patent applications which became controlled by the Company during the three -year period between the execution date of the Original KNOW Bio Agreements and December 29, 2018, directed towards nitric oxide-releasing compositions and methods of manufacturing thereof, including methods of manufacturing Nitricil compounds, and other nitric oxide-based therapeutics, to develop and commercialize products for all diagnostic, therapeutic, prophylactic and palliative uses for any disease, condition or disorder caused by certain oncoviruses (the “Oncovirus Field”). The Company also obtained a three -year exclusive option, subject to payment of separate option exercise fees, to include up to four additional specified oncoviruses in the Oncovirus Field. KNOW Bio also granted to the Company an exclusive license, with the right to sublicense, under any patents and patent applications which became controlled by KNOW Bio during the three -year period between the execution date of the Original KNOW Bio Agreements and December 29, 2018 and directed towards nitric oxide-releasing compositions and methods of manufacturing thereof, including methods of manufacturing Nitricil compounds, and other nitric oxide-based therapeutics, but not towards medical devices, to develop and commercialize products for use in the Oncovirus Field. Additionally, KNOW Bio agreed that KNOW Bio would not commercialize any products in the Oncovirus Field during the three -year period between the execution date of the Original KNOW Bio Agreements and December 29, 2018. Upon execution of the KNOW Bio Amendments, in exchange for the Oncovirus Field rights, the Company paid a non-refundable upfront payment of $250 . Products the Company develops in the Oncovirus Field based on Nitricil will not be subject to any further milestones, royalties or sublicensing payment obligations to KNOW Bio under the KNOW Bio Amendments. However, if the Company develops products in the Oncovirus Field that incorporate a certain nitric oxide-releasing composition specified in the KNOW Bio Amendments and (i) are covered by KNOW Bio patents or (ii) materially use or incorporate know-how of KNOW Bio or the Company related to such composition that is created during the three -year period between the execution date of the Original KNOW Bio Agreements and December 29, 2018, the Company would be obligated to make certain contingent milestone and royalty payments to KNOW Bio under the KNOW Bio Amendments. The rights granted to the Company in the Oncovirus Field in the KNOW Bio Amendments continue for so long as there is a valid patent claim under the Original KNOW Bio Agreements, and upon expiration continue on a perpetual non-exclusive basis, and are subject to the termination rights of KNOW Bio and the Company that are set forth in the Original KNOW Bio Agreements. In addition, under the KNOW Bio Amendments, KNOW Bio may terminate the rights granted to the Company in the Oncovirus Field if: (i) the Company does not file a first investigational new drug (“IND”) application with the FDA for a product in the Oncovirus Field by October 2020; or (ii) the Company does not file a first new drug application (“NDA”) with the FDA by October 2025 for a product in the Oncovirus Field and does not otherwise have any active clinical programs related to the Oncovirus Field at such time. The KNOW Bio Amendments also provide a mechanism whereby either party can cause a new chemical entity (“NCE”) covered by the Original KNOW Bio Agreements to become exclusive to such party by filing an IND on the NCE. An NCE that becomes exclusive to a party under this provision may not be commercialized by the other party until the later of expiration of patents covering the NCE or regulatory exclusivity covering the NCE. A party who obtains exclusivity for an NCE must advance development of the NCE pursuant to terms of the KNOW Bio Amendments in order to maintain such exclusivity; otherwise, such exclusivity will expire. The terms of the KNOW Bio Amendments were negotiated at arms-length and do not provide the Company with an ability to significantly influence KNOW Bio or its operations.

Research and Development Licens

Research and Development Licenses	3 Months Ended
	Mar. 31, 2019
Research and Development [Abstract]
Research and Development Licenses	Research and Development Licenses The Company has entered into various licensing agreements with universities and other research institutions under which the Company receives the rights, and in some cases substantially all of the rights, of the inventors, assignees or co-assignees to produce and market technology protected by certain patents and patent applications. The Company’s primary license agreement is with UNC and has been described in further detail within the subsection below. The counterparties to the Company’s various other licensing agreements are the University of Akron Research Foundation, Hospital for Special Surgery, Strakan International S.a.r.l., which is a licensee of the University of Aberdeen, KIPAX AB and KNOW Bio. The Company is generally required to make milestone payments based on development milestones and will be required to make royalty payments based on a percentage of future sales of covered products or a percentage of sublicensing revenue. As future royalty payments are directly related to future revenues (either sales or sublicensing), future commitments cannot be determined. No accrual for future payments under these agreements has been recorded, as the Company cannot estimate if, when or in what amount payments may become due. UNC License Agreement The Amended, Restated and Consolidated License Agreement dated June 27, 2012, as amended, (the “UNC Agreement”) provides the Company with an exclusive license to issued patents and pending applications directed to the Company’s library of Nitricil compounds, including patents issued in the U.S., Japan and Australia, with claims intended to cover NVN1000, the NCE for the Company’s current product candidates. The UNC Agreement requires the Company to pay UNC up to $425 in regulatory and commercial milestones on a licensed product by licensed product basis and a running royalty percentage in the low single digits on net sales of licensed products. Licensed products include any products being developed by the Company or by its sublicensees. Unless earlier terminated by the Company at its election, or if the Company materially breaches the agreement or becomes bankrupt, the UNC Agreement remains in effect on a country by country and licensed product by licensed product basis until the expiration of the last to expire issued patent covering such licensed product in the applicable country.

Licensing Arrangements

Licensing Arrangements	3 Months Ended
	Mar. 31, 2019
Collaboration Arrangements [Abstract]
Licensing Arrangements	Licensing Arrangements Sato License Agreement Significant Terms On January 12, 2017, the Company entered into a license agreement, and related amendment, with Sato Pharmaceutical Co., Ltd. (“Sato”), relating to SB204, its drug candidate for the treatment of acne vulgaris in Japan (the “Sato Agreement”). Pursuant to the Sato Agreement, the Company granted to Sato an exclusive, royalty-bearing, non-transferable right and license under certain of the Company’s intellectual property rights, with the right to sublicense with the Company’s prior written consent, to develop, use and sell products in Japan that incorporate SB204 in certain topical dosage forms for the treatment of acne vulgaris, and to make the finished form of such products. On October 5, 2018, the Company and Sato entered into the second amendment (the “Sato Amendment”) to the Sato Agreement (collectively, the “Amended Sato Agreement”). The Sato Amendment expanded the Sato Agreement to include SB206, the Company’s drug candidate for the treatment of viral skin infections. Pursuant to the Amended Sato Agreement, the Company granted to Sato an exclusive, royalty-bearing, non-transferable license under certain of its intellectual property rights, with the right to sublicense with the Company’s prior written consent, to develop, use and sell products in Japan that incorporate SB204 or SB206 in certain topical dosage forms for the treatment of acne vulgaris or viral skin infections, respectively, and to make the finished form of such products. The Company or its designated contract manufacturer will supply finished product to Sato for use in the development of SB204 and SB206 in the licensed territory. The rights granted to Sato do not include the right to manufacture the active pharmaceutical ingredient (“API”) of SB204 or SB206; rather, the parties agreed to negotiate a commercial supply agreement pursuant to which the Company or its designated contract manufacturer would be the exclusive supplier to Sato of the API for the commercial manufacture of licensed products in the licensed territory. Under the terms of the Amended Sato Agreement, the Company also has exclusive rights to certain intellectual property that may be developed by Sato in the future, which the Company could choose to use for its own development and commercialization of SB204 or SB206 outside of Japan. Under the Amended Sato Agreement, in exchange for the SB204 and SB206 license rights granted to Sato, Sato agreed to pay the Company the following: • An upfront payment of 1.25 billion Japanese Yen, or “JPY”, payable in installments of 0.25 billion JPY, 0.5 billion JPY and 0.5 billion JPY on October 5, 2018, February 14, 2019 and September 13, 2019 , respectively. This is in addition to the 1.25 billion JPY (approximately $ 10,813 USD) paid on January 19, 2017 following the execution of the Sato Amendment on January 12, 2017. On October 23, 2018, the Company received the first installment from the Amended Sato Agreement of 0.25 billion JPY (approximately $2,224 USD). On March 14, 2019, the Company received the second installment payment related to the Amended Sato Agreement of 0.5 billion JPY (approximately $4,460 USD). • Up to an aggregate of 1.75 billion JPY (adjusted from 2.75 billion JPY in the Sato Agreement) upon the achievement of various development and regulatory milestones, including (i) a 0.25 billion JPY (approximately $2,162 USD) milestone payment received during the fourth quarter of 2018 following Sato’s initiation of a Phase 1 trial in Japan and (ii) an aggregate of 1.0 billion JPY that becomes payable upon the earlier occurrence of specified fixed future dates or the achievement of milestone events. • Up to an aggregate of 3.9 billion JPY (adjusted from 0.9 billion JPY in the Sato Agreement) upon the achievement of various commercial milestones. • A tiered royalty ranging from a mid-single digit to a low-double digit percentage (adjusted from a mid-single digit percentage in the Sato Agreement) of net sales of licensed products in the licensed territory, subject to a reduction in the royalty payments in certain circumstances. The term of the Amended Sato Agreement (and the period during which Sato must pay royalties under the amended license agreement) expires on the twentieth anniversary of the first commercial sale of a licensed product in the licensed field in the licensed territory (adjusted from the tenth anniversary of the first commercial sale in the license agreement). The term of the Amended Sato Agreement may be renewed with respect to a licensed product by mutual written agreement of the parties for additional two year periods following expiration of the initial term. All other material terms of the license agreement remain unchanged by the Sato Amendment. Sato is responsible for funding the development and commercial costs for the program that are specific to Japan. The Company is obligated to perform certain oversight, review and supporting activities for Sato, including: (i) using commercially reasonable efforts to obtain marketing approval of SB204 and SB206 in the U.S., (ii) sharing all future scientific information the Company may obtain during the term of the Amended Sato Agreement pertaining to SB204 and SB206, (iii) performing certain additional preclinical studies if such studies are deemed necessary by the Japanese regulatory authority, up to and not to exceed a total cost of $1,000 and (iv) participating in a joint committee that oversees, reviews and approves Sato’s development and commercialization activities under the Amended Sato Agreement. Additionally, the Company has granted Sato the option to use the Company’s trademarks in connection with the commercialization of licensed products in the licensed territory for no additional consideration, subject to the Company’s approval of such use. The Amended Sato Agreement may be terminated by (i) Sato without cause upon 120 days ’ advance written notice to the Company, (ii) either party in the event of the other party’s uncured material breach upon 60 days ’ advance written notice, (iii) force majeure, (iv) either party in the event of the other party’s dissolution, liquidation, bankruptcy or insolvency and (v) the Company immediately upon written notice if Sato challenges the validity, patentability, or enforceability of any of the Company’s patents or patent applications licensed to Sato under the Amended Sato Agreement. In the event of a termination, no portion of the upfront fees received from Sato are refundable.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Sato Agreement The Company assessed the Sato Agreement in accordance with Topic 606 and concluded that the contract counterparty, Sato, is a customer within the scope of Topic 606. The Company identified the following promises under the Sato Agreement: (i) the grant of the intellectual property license to Sato, (ii) the obligation to participate in a joint committee that oversees, reviews, and approves Sato’s research and development activities and provides advisory support during Sato’s development process, (iii) the obligation to manufacture and supply Sato with all quantities of licensed product required for development activities in Japan, and (iv) the stand-ready obligation to perform any necessary repeat preclinical studies, up to $1,000 in cost. The Company determined that these promises were not individually distinct because Sato can only benefit from these licensed intellectual property rights and services when bundled together; they do not have individual benefit or utility to Sato. As a result, all promises have been combined into a single performance obligation. The Sato Agreement also provides that the two parties agree to negotiate in good faith the terms of a commercial supply agreement pursuant to which the Company or a third party manufacturer would be the exclusive supplier to Sato of the API for the commercial manufacture of licensed products in the licensed territory. The Company concluded this obligation to negotiate the terms of a commercial supply agreement does not create (i) a legally enforceable obligation under which the Company may have to perform and supply Sato with API for commercial manufacturing or (ii) a material right because the incremental commercial supply fee consideration agreed upon between the parties in the Sato Agreement is representative of a stand-alone selling price for the supply of API and does not represent a discount. Therefore, this contract provision is not considered to be a promise to deliver goods or services and is not a performance obligation or part of the combined single performance obligation described above. Amended Sato Agreement On October 5, 2018, the Company and Sato entered into the Amended Sato Agreement. The Sato Amendment expanded the Sato Agreement to include SB206, the Company’s drug candidate for the treatment of viral skin infections. The Company assessed the Amended Sato Agreement in accordance with Topic 606 and concluded the contract modification should incorporate the additional goods and services provided for in the Amendment into the existing, partially satisfied single bundled performance obligation that will continue to be delivered to Sato over the remaining development period. This contract modification accounting is concluded to be appropriate as the additional goods and services conveyed under the Sato Amendment were determined to not be distinct from the single performance obligation, and the additional consideration provided did not reflect the standalone selling price of those additional goods and services. As such, the Company recorded a cumulative adjustment as of the amendment execution date to reflect revenue that would have been recognized cumulatively for the partially completed bundled performance obligation. The Company concluded that the following consideration would be included in the transaction price as they were (i) received prior to March 31, 2019 , or (ii) payable upon specified fixed dates in the future and are not contingent upon clinical or regulatory success in Japan: • The 1.25 billion JPY (approximately $10,813 USD) original upfront payment received on January 19, 2017 following the execution of the Sato Agreement on January 12, 2017. • A milestone payment of 0.25 billion JPY (approximately $2,162 USD) received during the fourth quarter of 2018 following Sato’s initiation of a Phase 1 trial in Japan. • The Sato Amendment upfront payment of 1.25 billion JPY, payable in installments of 0.25 billion JPY, 0.5 billion JPY and 0.5 billion JPY on October 5, 2018, February 14, 2019 and September 13, 2019, respectively. On October 23, 2018, the Company received the first installment from the Amended Sato Agreement of 0.25 billion JPY (approximately $2,224 USD). On March 14, 2019, the Company received the second installment payment related to the Amended Sato Agreement of 0.5 billion JPY (approximately $4,460 USD). • An aggregate of 1.0 billion JPY in non-contingent milestone payments that become payable upon the earlier occurrence of specified fixed dates in the future or the achievement of specified milestone events. The following table presents the Company’s contract assets and contract liabilities balances for the periods indicated. Contract Asset Contract Liability Net Deferred Revenue December 31, 2018 $ 17,790 $ 24,757 $ 6,967 March 31, 2019 $ 13,330 $ 23,657 $ 10,327 Short-term Deferred Revenue Long-term Deferred Revenue Net Deferred Revenue December 31, 2018 $ 4,401 $ 2,566 $ 6,967 March 31, 2019 $ 4,401 $ 5,926 $ 10,327 The Company has recorded the Sato Agreement and Amended Sato Agreement transaction price, including the upfront payments received and the unconstrained variable consideration, as deferred revenue (comprised of (i) a contract liability; net of (ii) a contract asset). The change in the net deferred revenue balance during the three months ended March 31, 2019 was associated with the receipt of the second installment payment of 0.5 billion JPY (approximately $4,460 USD, and recognition of license and collaboration revenue associated with the Company’s performance during the period (continued amortization of deferred revenue). During the three months ended March 31, 2019 and 2018 , the Company recognized $1,100 and $649 , respectively, in license and collaboration revenue under this agreement. The Company has concluded that the above consideration is probable of not resulting in a significant revenue reversal and therefore included in the transaction price and is allocated to the single performance obligation. No other variable consideration under the Amended Sato Agreement is probable of not resulting in a significant revenue reversal as of March 31, 2019 and therefore, is currently fully constrained and excluded from the transaction price. The Company evaluated the timing of delivery for each of the obligations and concluded that a time-based input method is most appropriate because Sato is accessing and benefiting from the intellectual property and technology (the predominant items of the combined performance obligation) ratably over the duration of Sato’s estimated development period in Japan. Although the Company concluded that the intellectual property is functional rather than symbolic, the services provided under the performance obligation are provided over time. Therefore, the allocated transaction price will be recognized using a time-based input method that results in straight-line recognition over the Company’s performance period. Prior to the Sato Amendment, the Company estimated the Sato Agreement development time line for the SB204 product candidate to be approximately 5 years , starting in February 2017 and completing in the first quarter of 2022. With the Amended Sato Agreement, the Company and Sato are now advancing both the SB204 and SB206 product candidates for the Japan territory. The parties are working collaboratively to reach agreement with respect to the Japan territory development plan, including a corresponding time line and estimated duration for the development programs in whole. As of March 31, 2019 , the estimated time line is 7.5 years . The Company notes that it monitors and reassesses the estimated performance period for purposes of revenue recognition during each reporting period. Therefore, if the duration of the development program time line is affected by the establishment or subsequent adjustments to a mutually agreed upon SB204 and SB206 development plan in the Japan territory, the Company will adjust its estimated performance period for revenue recognition purposes accordingly, as needed. In future periods, the Company will lift the variable consideration constraint from each contingent payment when there is no longer a probable likelihood of significant revenue reversal. When the constraint is lifted from a milestone payment, the Company will recognize the incremental transaction price using the same time-based input method that is being used to recognize the revenue, which results in straight-line recognition over the performance period. If the Company’s performance is not yet completed at the time that the constraint is lifted, a cumulative catch-up adjustment will be recognized in the period. If no other performance is required by the Company at the time the constraint is lifted, the Company expects to recognize all revenue associated with such milestone payments at the time that the constraint is lifted. Contract costs—Sato Agreement The Company has incurred certain fees and costs in the process of obtaining the Amended Sato Agreement that were payable upon contract execution and, therefore, have been recognized as other assets and amortized as general and administrative expense on a straight-line basis over the same estimated performance period being used to recognize the associated revenue. These fees are associated with the following two arrangements and are described as follows: • The Company entered into an agreement with a third party to assist the Company in exploring the licensing opportunity which led to the execution of the Sato Agreement. The Company is obligated to pay the third party a low-single-digit percentage of all upfront and milestone payments the Company receives from Sato under the Amended Sato Agreement. • The intellectual property rights granted to Sato under the Sato Agreement include certain intellectual property rights which the Company has licensed from UNC. Under the Company’s license agreement with UNC described in Note 3—Research and Development Licenses, the Company is obligated to pay UNC a running royalty percentage in the low single digits on net sales of licensed products, including net sales that may be generated by Sato. Additionally, the Company is obligated to make payments to UNC that represent the portion of the Sato upfront and milestone payments that were estimated to be directly attributable to the UNC intellectual property rights included in the license to Sato. Performance Obligations under the Sato Agreement The net amount of existing performance obligations under long-term contracts unsatisfied as of March 31, 2019 was $10,327 . The Company expects to recognize approximately 19% of the remaining performance obligations as revenue over the next 12 months , and the balance thereafter. The Company applied the practical expedient and does not disclose information about variable consideration related to sales-based or usage-based royalties promised in exchange for a license of intellectual property. This expedient specifically applied to the sales-based milestone payments that are present in the Amended Sato Agreement ( 3.9 billion JPY), as well as percentage-based royalty payments in the Sato Agreement that are contingent upon future sales. Research and Development Services to KNOW Bio As described in Note 2—Know Bio, LLC, the Company entered the KNOW Bio Services Agreement during 2017 and provided research and development services on a fee-for-service basis. After assessing revenue according to the five-step model of ASC 606, the Company determined that contract research and development services revenue should be recognized in the period in which the services are performed. During the three months ended March 31, 2019 and 2018, the Company recognized $0 and $9 , respectively, in research and development services revenue for services performed under the KNOW Bio Services Agreement.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment consisted of the following: March 31, December 31, Computer equipment $ 575 $ 577 Furniture and fixtures 312 312 Laboratory equipment 7,494 7,442 Office equipment 400 400 Building related to facility lease obligation — 10,557 Leasehold improvements 7,053 1,168 Property and equipment, gross 15,834 20,456 Less: Accumulated depreciation and amortization (4,177 ) (4,588 ) Total property and equipment, net $ 11,657 $ 15,868 Depreciation and amortization expense was $503 and $401 for the three months ended March 31, 2019 and 2018 , respectively. See Note 1—Organization and Significant Accounting Policies and Note 7—Commitments and Contingencies regarding the adoption of Topic 842, Leases , and its impact to property and equipment, net for the three month ended March 31, 2019 .

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Obligations The Company leases office space and certain equipment under non-cancelable lease agreements. Prior to January 1, 2019, the Company applied the accounting guidance in ASC 840, Leases , to its lease agreements. The leases were reviewed for classification as operating or capital leases. For operating leases, rent was recognized on a straight-line basis over the lease period. For capital leases, the Company recorded the leased asset with a corresponding liability and amortized the asset over the lease term. Payments were recorded as reductions to the liability with an appropriate interest charge recorded based on the then-outstanding remaining liability. The Company considered the nature of the renovations and the Company’s involvement during the construction period of previously leased office space to determine if it is considered to be the owner of the construction project during the construction period. If the Company determined that it was the owner of the construction project, it was required to capitalize the fair value of the building as well as the construction costs incurred, including capitalized interest, on its consolidated balance sheet along with a corresponding financing liability (“build-to-suit accounting”). Upon completion of the construction of the facility under a build-to-suit lease, the Company assessed whether the circumstances qualified for sales recognition under the sale-leaseback accounting guidance. If the lease met the sale-leaseback criteria, the Company would remove the asset and related financial obligation from the balance sheet and evaluate the lease for treatment as a capital or operating lease. If upon completion of construction, the project did not meet the sale-leaseback criteria, the leased property was treated as an asset financing for financial reporting purposes. The portion of the facility financing obligation representing the principal that was to be repaid in the following 12 months was classified as a current liability in the condensed consolidated balance sheets, with the remaining portion of the obligation classified as a noncurrent liability. Beginning January 1, 2019, the Company applies the accounting guidance in ASC 842, Leases. As such, the Company assesses all arrangements, that convey the right to control the use of property, plant and equipment, at inception, to determine if it is, or contains, a lease based on the unique facts and circumstances present in that arrangement. For those leases identified, the Company determines the lease classification, recognition, and measurement at the lease commencement date. For arrangements that contain a lease the Company: (i) identifies lease and non-lease components; (ii) determines the consideration in the contract; (iii) determines whether the lease is an operating or financing lease; and (iv) recognizes lease Right of Use (“ROU”) assets and corresponding lease liabilities. Lease liabilities are recorded based on the present value of lease payments over the expected lease term. The corresponding ROU asset is measured from the initial lease liability, adjusted by (i) accrued or prepaid rents; (ii) remaining unamortized initial direct costs and lease incentives; and (iii) any impairments of the ROU asset. The interest rate implicit in the Company’s lease contracts is typically not readily determinable and as such, the Company uses its incremental borrowing rate based on the information available at the lease commencement date, which represents an internally developed rate that would be incurred to borrow, on a collateralized basis, over a similar term, an amount equal to the lease payments in a similar economic environment. The weighted average discount rate utilized on our operating lease liabilities as of March 31, 2019 was 9.85% . The weighted average remaining lease term for our operating leases as of March 31, 2019 was 7.25 years. Primary Facility Lease In August 2015, the Company entered into a lease agreement for approximately 51,000 rentable square feet of facility space in Morrisville, North Carolina, commencing in April 2016 (the “Primary Facility Lease”). The initial term of the Primary Facility Lease extends through June 30, 2026 . The Company has an option to extend the Primary Facility Lease by five years upon completion of the initial lease term; however, the renewal period was not included in the calculation of the lease obligation. Current contractual base rent payments are $95 per month, subject to a three percent increase annually over the term of the Primary Facility Lease. Prior to January 1, 2019, the Company applied the accounting guidance in ASC 840. Based on that guidance, the facility was accounted for as an asset financing, with the building asset and related facility financing obligation remaining on the Company’s balance sheet. The building asset was being depreciated over a 25 year period and the facility financing obligation was amortized so that the net carrying value of the building asset and the facility financing obligation were to be equivalent at the end of the initial term of the lease agreement. Monthly rental payments were allocated between principal and interest expense associated with the facility financing obligation, as well as grounds rent expense of $8 per month. The Company had recorded an asset related to the building and construction costs within property and equipment of $10,557 as of December 31, 2018. The non-current facility lease obligation on the Company’s condensed consolidated balance sheet was $7,998 as of December 31, 2018 . During the three months ended March 31, 2018 , the Company recognized interest expense related to the primary facility lease of $261 , and there was $41 of accrued interest included in other accrued expenses as of December 31, 2018 . The Company adopted Topic 842 as of January 1, 2019 using the modified retrospective transition method and initially applied the transition provisions as of January 1, 2019. This transition method allowed the Company to continue to apply the legacy guidance in ASC 840 for periods prior to 2019 and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit as of the date of adoption. The Company elected the package of transition practical expedients, which, among other things, allowed the Company to keep the historical lease classifications and not have to reassess the lease classification for any existing leases as of the date of adoption. The Company also made an accounting policy election to apply the short-term lease exception, which allows the Company to exclude leases with an initial term of twelve months or less from the consolidated balance sheets. As a result of the adoption of Topic 842, the Company derecognized $10,557 of building asset (property, plant and equipment), and $7,998 of facility financing obligation associated with previously existing build-to-suit arrangement related to its sole corporate and manufacturing facility. The Company also capitalized leasehold improvements and ROU assets of $5,885 and $1,827 , respectively, and recorded lease liabilities for operating leases totaling $6,786 , as of January 1, 2019. The capitalized leasehold improvement assets recorded as part of the adoption of Topic 842 were previously included within the derecognized building asset as part of the previous build-to-suit arrangement. The Company also recognized an increase of $714 to accumulated deficit related to its de-recognition of its previously recorded build-to-suit arrangement. The Company has elected to separate lease components (fixed rent payments) with non-lease components (common-area maintenance costs) on our real estate assets. Fixed lease payments on operating leases are recognized over the expected term of the lease on a straight-line basis. Variable lease expenses that are not considered fixed are expensed as incurred. Fixed and variable lease expense on operating leases is recognized within operating expenses within our condensed consolidated statements of operations. We have elected the short-term lease exemption and, therefore, do not recognize a ROU asset or corresponding liability for lease arrangements with an original term of 12 months or less. Rent expense, including both short-term and variable lease components associated with the primary facility lease, was $157 and $42 for the three months ended March 31, 2019 and 2018, respectively. The Company’s supplemental non-cash disclosure for its ROU assets obtained in exchange for lease liabilities was $1,827 for the three months ended March 31, 2019. At January 1, 2019, maturities of operating lease liabilities over each of the next five years and thereafter were as follows: Operating Leases 2019 $ 1,170 2020 1,205 2021 1,241 2022 1,278 2023 1,317 Thereafter 3,467 Total minimum lease payments $ 9,678 Less imputed interest (2,871 ) Total lease liability $ 6,807 Primary Facility Sublease In July 2018, the Company and a third-party tenant entered into a sublease of approximately 6,400 square feet of office space at the Company’s headquarters. The sublease has a three -year, non-cancellable term and provides for monthly rental income to the Company of approximately $12 per month through July 2021. The Company has classified the sublease as an operating lease pursuant to classification criteria in ASC 842 and is recognizing the rental income on a straight-line basis over the lease term. Contingencies From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. See Legal Proceedings below for further discussion of pending legal claims. The Company has entered into, and expects to continue to enter into, contracts in the normal course of business with various third parties who support its clinical trials, preclinical research studies and other services related to its development activities. The scope of the services under these agreements can generally be modified at any time, and these agreements can generally be terminated by either party after a period of notice and receipt of written notice. There have been no material contract terminations as of March 31, 2019 . Legal Proceedings In prior filings, the Company reported that it was subject to putative stockholder class action lawsuits that were filed in November 2017 in the United States District Court for the Middle District of North Carolina against the Company and certain of its current and former directors and officers, which were consolidated under the case name In re Novan, Inc. Securities Litigation . The consolidated amended complaint filed by the designated lead plaintiff asserted claims for violation of Sections 11 and 15 of the Securities Act of 1933 and Sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 promulgated thereunder, in connection with statements related to the Company’s Phase 3 clinical trials of SB204. On June 14, 2018, the Company filed a motion to dismiss the consolidated amended complaint. On November 30, 2018, a federal magistrate judge entered an order recommending that the district court grant the Company’s motion. The plaintiff filed objections to this recommendation and the Company filed a response. On January 28, 2019, the district court adopted the magistrate judge’s recommendation, dismissed the action with prejudice and entered judgment in favor of the Company and against the plaintiff. The plaintiff did not appeal this dismissal and judgment. As such, the Company has concluded that this matter is closed. Other than as described above, the Company is not currently a party to any material legal proceedings and is not aware of any claims or actions pending or threatened against the Company that the Company believes could have a material adverse effect on the Company’s business, operating results, cash flows or financial statements. In the future, the Company might from time to time become involved in litigation relating to claims arising from its ordinary course of business. Compensatory Obligations In conjunction with the departures of three former Company officers in 2019 and 2018, the Company entered into separation and general release agreements that included separation benefits consistent with the Company’s obligations under their previously existing employment agreements for “separation from service” for “good reason.” The Company recognized related severance expense of $878 and $332 during the three months ended March 31, 2019 and 2018, respectively. The remaining accrued severance obligation in respect of the three former officers was $621 as of March 31, 2019 , which is included in accrued compensation in the accompanying condensed consolidated balance sheet. The Company also recognized non-cash stock compensation expense of $0 and $212 during the three months ended March 31, 2019 and 2018, respectively, related to the accelerated vesting of the former officers’ stock options. In November 2018, the Company realigned its overall employee headcount to reduce certain fixed costs. Total employee severance costs associated with this action are expected to be $306 , of which $61 was expensed during the three months ended March 31, 2019 . As of March 31, 2019 , severance costs of $82 were accrued in the accompanying consolidated balance sheet. See Note 10—Share-Based Compensation regarding the contingent award of Stock Appreciation Rights granted in August 2018. See Note 11—Tangible Stockholder Return Plan regarding the Tangible Stockholder Return Plan adopted in August 2018.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Capital Structure In conjunction with the completion of the Company’s initial public offering in September 2016, the Company further amended its amended and restated certificate of incorporation and amended and restated its bylaws. The amendment provides for 210,000,000 authorized shares of capital stock, of which 200,000,000 shares have been designated as $0.0001 par value common stock and 10,000,000 shares have been designated as $0.0001 par value preferred stock. Common Stock The Company’s common stock has a par value of $0.0001 per share and consists of 200,000,000 authorized shares as of March 31, 2019 and December 31, 2018 . There were 26,069,734 and 26,056,735 shares of voting common stock outstanding as of March 31, 2019 and December 31, 2018 , respectively. The Company had reserved shares of common stock for future issuance as follows: March 31, 2019 December 31, 2018 Outstanding stock options (Note 10) 1,645,357 1,671,666 Warrants to purchase common stock issued in January 2018 Offering (Note 9) 10,000,000 10,000,000 For possible future issuance under 2016 Stock Plan (Note 10) 703,519 699,376 12,348,876 12,371,042 Preferred Stock The Company’s amended and restated certificate of incorporation provides the Company’s board of directors with the authority to issue $0.0001 par value preferred stock from time to time in one or more series by adopting a resolution and filing a certificate of designations. Voting powers, designations, preferences, dividend rights, conversion rights and liquidation preferences shall be stated and expressed in such resolutions. There were 10,000,000 shares designated as preferred stock and no shares outstanding as of March 31, 2019 and December 31, 2018 .

Warrants

Warrants	3 Months Ended
	Mar. 31, 2019
Warrants and Rights Note Disclosure [Abstract]
Warrants	Warrants The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in which to classify them for each reporting period, pursuant to the fair value measurements policy described in Note 1—Organization and Significant Accounting Policies. This determination requires significant judgments to be made. On January 9, 2018, the Company sold an aggregate of 10,000,000 shares of common stock and issued warrants to purchase up to 10,000,000 shares of common stock at a public offering price of $3.80 per share of common stock and accompanying warrant. Pursuant to the warrant agreement and form of warrant dated January 9, 2018 (the “Warrant Agreement”), the warrant exercise price is $4.66 per share and the warrants will expire four years from the date of issuance. The Warrant Agreement includes a provision whereby the exercisability of the warrants may be limited if, upon exercise, the warrant holder or any of its affiliates would beneficially own more than 4.99% (or an amount up to 9.99% if the holder so elects) of the Company’s common stock. The Warrant Agreement also provides that the aforementioned exercise limitation provision is not applicable to any warrant holder that beneficially owns 10.0% or more of the Company’s outstanding common stock immediately following the closing of the January 2018 Offering and the issuance of the accompanying warrants. If, at any time the warrants are outstanding, any fundamental transaction occurs, as described in the Warrant Agreement and generally including any consolidation or merger whereby another entity acquires more than 50% of the Company’s outstanding common stock, or the sale of all or substantially all of its assets, the successor entity must assume in writing all of the obligations to the warrant holders. Additionally, in the event of a fundamental transaction, the Warrant Agreement provides that each warrant holder will have the right to require the Company, or its successor, to repurchase the warrants for an amount of cash equal to the Black-Scholes value of the remaining unexercised portion of the warrants. Further, the Warrant Agreement states that the volatility input used to derive such Black-Scholes value is the greater of the Company’s historical volatility or 100% . Due to the provision that the warrant holder has the option to receive a cash settlement, equal to the Black-Scholes fair value of the remaining unexercised portion of the warrant, in the event that there is a fundamental transaction, the Company has classified the warrants as liabilities in accordance with ASC 480, Distinguishing Liabilities from Equity . There were no exercises of warrants during the three months ended March 31, 2019 and 2018 . The following table presents the Company’s warrant liability measured at fair value on a recurring basis as of March 31, 2019 and December 31, 2018 : March 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Liabilities: Warrant liability $ — $ — $ 1,628 $ 1,628 Total liabilities at fair value $ — $ — $ 1,628 $ 1,628 December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Liabilities: Warrant liability $ — $ — $ 1,240 $ 1,240 Total liabilities at fair value $ — $ — $ 1,240 $ 1,240 The fair value of the common stock warrants is estimated using a valuation model that approximates a Monte Carlo simulation model, which takes into consideration the probability of a fundamental transaction occurring during the contractual term of the warrants. This valuation model, which includes inputs classified as Level 3 in the fair value hierarchy, estimated a fair value of $0.16 and $0.12 per common stock warrant as of March 31, 2019 and December 31, 2018 , respectively. The inputs to the valuation model that approximates a Monte Carlo simulation model are presented below. March 31, 2019 December 31, 2018 Estimated dividend yield — — Expected volatility 81.21%-100% 77.74%-100% Risk-free interest rate 2.21 % 2.46 % Expected term (years) 2.78 3.02 Fair value per share of common stock underlying the warrant $ 0.96 $ 0.83 Warrant exercise price $ 4.66 $ 4.66 Due to the Company’s limited historical stock price data, the Company estimates stock price volatility based on the actual historical volatility of a group of comparable publicly traded companies observed over a historical period equal to the expected life of the warrant. The increase of $388 and decrease of $3,558 in fair value of the warrants for the three months ended March 31, 2019 and 2018 , respectively, are included as components of other income and expense in the Company’s condensed consolidated statements of operations and comprehensive loss. The change in the warrant liability and the corresponding unrealized loss/gain recognized during the three months ended March 31, 2019 and 2018 is primarily due to the fluctuations in the market price of the Company’s underlying common stock from the date of issuance to March 31, 2019 , in addition to fluctuations in the other valuation model inputs. The following table summarizes the change in the fair value of the warrant liability, which is valued using significant unobservable Level 3 inputs, for the three months ended March 31, 2019 and 2018 : Three Months Ended March 31, 2019 2018 Beginning Balance $ 1,240 $ — Issuance $ — $ 17,806 Revaluations Included In Earnings $ 388 $ (3,558 ) Exercises $ — $ — Expirations $ — $ — Ending Balance $ 1,628 $ 14,248

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation 2016 Stock Plan During the three months ended March 31, 2019 , the Company continued to administer and grant awards under the 2016 Incentive Award Plan (the “2016 Plan”), the Company’s only active equity incentive plan. Certain of the Company’s outstanding and exercisable stock options remain subject to the terms of the Company’s 2008 Stock Plan (the “2008 Plan”), which is the predecessor to the 2016 Plan and became inactive upon adoption of the 2016 Plan effective September 20, 2016. On August 16, 2018, the board of directors approved an amendment to the 2016 Plan, subject to stockholder approval, to increase the number of shares reserved under the 2016 Plan by 1,000,000 and to increase the award limit on the maximum aggregate number of shares of the Company’s common stock that may be granted to any one person during any calendar year from 250,000 to 1,000,000 shares of the Company’s common stock. All other material terms of the 2016 Plan otherwise remain unchanged. Stock Appreciation Rights On August 8, 2018 , the Company entered into an employment agreement with G. Kelly Martin (the “Employment Agreement”). The Employment Agreement provided for 1,000,000 SARs granted on a contingent basis that shall be considered irrevocably forfeited and voided in full if the Company fails to obtain stockholder approval for an amendment to the 2016 Plan, described above. If such approval is not obtained, the Company will pay Mr. Martin the cash equivalent of the value of the SARs. The SARs entitle Mr. Martin to a payment (in cash, shares of common stock or a combination of both) equal to the fair market value of one share of the Company’s common stock on the date of exercise less the exercise price of $3.80 per share. The SARs will vest in full on February 1, 2020. The SARs will be deemed automatically exercised and settled as of February 1, 2020, provided Mr. Martin remains continuously employed with the Company through such date unless vesting is otherwise expressly accelerated pursuant to the SAR Agreement. Due to the cash settlement feature of the SAR grant, subject to stockholder approval, these share-based payment awards should be classified as liabilities and the amount of compensation cost recognized must be based on the fair value of those liabilities. Therefore, the obligation is recorded as a liability on the Company’s condensed consolidated balance sheet at the estimated fair value on the date of issuance and is re-valued each subsequent reporting period with adjustments to the fair value recognized as share-based compensation expense in the condensed consolidated statements of operations. During the three months ended March 31, 2019 , the Company recorded employee share-based compensation expense related to the SARs of $7 . There was no share-based compensation expense related to SARs during the three months ended March 31, 2018 . In addition, the corresponding obligation is recorded within other long-term liabilities on the Company’s condensed consolidated balance sheet as of March 31, 2019 . Inducement Grants In May 2018, the Company awarded nonstatutory stock options to purchase an aggregate of 100,500 shares of common stock to newly-hired employees, not previously employees or directors of the Company, as inducements material to the individuals’ entering into employment with the Company within the meaning of Nasdaq Listing Rule 5635(c)(4) (the “Inducement Grants”). The Inducement Grants have a grant date of May 31, 2018 and an exercise price of $3.15 per share. The Inducement Grants were awarded outside of the Company’s 2016 Plan, pursuant to Nasdaq Listing Rule 5635(c)(4), but have terms and conditions generally consistent with the Company’s 2016 Plan and vest over three years, with one-third of the award vesting on each annual anniversary of the employee’s employment commencement date, subject to the employee’s continued service as an employee through the vesting period. Stock Compensation Expense During the three months ended March 31, 2019 and 2018 , the Company recorded employee share-based compensation expense for equity-based awards of $214 and $887 , respectively. Total share-based compensation expense for equity-based awards included in the condensed consolidated statements of operations and comprehensive loss is as follows: Three Months Ended March 31, 2019 2018 Research and development $ 61 $ 420 General and administrative 153 467 $ 214 $ 887 Stock option activity for the three months ended March 31, 2019 is as follows: Shares Subject to Outstanding Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Options outstanding as of December 31, 2018 1,671,666 $ 5.42 Options granted 147,500 1.31 Options forfeited (160,810 ) 4.64 Options exercised (12,999 ) 0.76 Options outstanding as of March 31, 2019 1,645,357 $ 5.17 7.37 $ — As of March 31, 2019 , there were a total of 1,645,357 stock options outstanding, including 100,500 inducement grants awarded in May 2018. In addition, there were 703,519 shares available for future issuance under the 2016 Plan as of March 31, 2019 . Tangible Stockholder Return Plan Performance Plan On August 2, 2018, the Company’s board of directors approved and established the Tangible Stockholder Return Plan, which is a performance-based long-term incentive plan (the “Performance Plan”). The Performance Plan was effective immediately upon approval and expires on March 1, 2022 . The Performance Plan covers all employees, including the Company’s executive officers, consultants and other persons deemed eligible by the Company’s compensation committee. The core underlying metric of the Performance Plan is the achievement of two share price goals for the Company’s common stock, which if achieved, would represent measurable increases in stockholder value. The Performance Plan is tiered, with two separate tranches, each of which has a distinct share price target (measured as the average publicly traded share price of the Company’s common stock on the Nasdaq stock exchange for a 30 consecutive trading day period) that will, if achieved, trigger a distinct fixed bonus pool. The share price target for the first tranche and related bonus pool are $11.17 per share and $25,000 , respectively. The share price target for the second tranche and related bonus pool are $25.45 per share and $50,000 , respectively. The compensation committee has discretion to distribute the bonus pool related to each tranche among eligible participants by establishing individual minimum bonus amounts before, as well as by distributing the remainder of the applicable pool after, the achievement of each tranche specific share price target. Otherwise, if the Company does not achieve one or both related share price targets, as defined, no portion of the bonus pools will be paid. The Performance Plan provides for the distinct fixed bonus pools to be paid in the form of cash. However, the compensation committee has discretion to pay any bonus due under the Performance Plan in the form of cash, shares of the Company’s common stock or a combination thereof, provided that the Company’s stockholders have approved the reservation of shares of the Company’s common stock for such payment. The Performance Plan permits the compensation committee to make bonus awards subject to varying payment terms, including awards that vest and are payable immediately upon achieving an applicable share price target as well as awards that pay over an extended period (either with or without ongoing employment requirements). The Performance Plan contemplates that no bonus award payments will be delayed beyond 24 months for named executive officers or more than 12 months for all other participants. For purposes of determining whether a share price target has been met, the share price targets will be adjusted in the event of any stock splits, cash dividends, stock dividends, combinations, reorganizations, reclassifications or similar events. In the event of a change in control, as defined in the Performance Plan, during the term of the Performance Plan, a performance bonus pool will be generated based on pro-rata progress toward achievement of the applicable share price target through the date of the change in control. The Company has concluded that the Performance Plan is within the scope of ASC 718 , Compensation — Stock Compensation as the underlying plan obligations are based on the potential attainment of certain market share price targets of the Company’s common stock. Any awards under the Performance Plan would be payable, at the discretion of the Company’s compensation committee following the achievement of the applicable share price target, in cash, shares of the Company’s common stock, or a combination thereof, provided that, prior to any payment in common stock, the Company’s stockholders have approved the reservation of shares of the Company’s common stock for such payment. ASC 718 requires that a liability-based award should be classified as a liability on the Company’s condensed consolidated balance sheets and the amount of compensation cost recognized should be based on the fair value of the liability. When a liability-based award includes both a service and market condition, the market condition is taken into account when determining the appropriate method to estimate fair value and the compensation cost is amortized over the estimated service period. Therefore, the liability associated with the Performance Plan obligation is recorded within other long-term liabilities on the Company’s condensed consolidated balance sheets at the estimated fair value on the date of issuance and is re-valued each subsequent reporting period end. The Company recognizes share-based compensation expense within operating expenses in the condensed consolidated statements of operations, including adjustments to the fair value of the liability-based award, on a straight-line basis over the requisite service period. The fair value of obligations under the Performance Plan are estimated using a Monte Carlo simulation approach. The Company’s common stock price is simulated under the Geometric Brownian Motion framework under each simulation path. The other assumptions for the Monte Carlo simulation include the risk-free interest rate, estimated volatility and the expected term. Expected stock price volatility is based on the actual historical volatility of a group of comparable publicly traded companies observed over a historical period equal to the expected remaining life of the plan. The fair value of the underlying common stock is the published closing market price on the Nasdaq Global Market as of each reporting date. The risk-free interest rate is based on the U.S. Treasury yield curve in effect on the date of valuation equal to the remaining expected life of the plan. The dividend yield percentage is zero because the Company does not currently pay dividends, nor does it intend to do so during the expected term of the plan. The expected life of bonus awards under the Performance Plan is assumed to be equivalent to the remaining contractual term based on the estimated service period including the service inception date of the plan participants and the contractual end of the Performance Plan. During the three months ended March 31, 2019 , the Company recorded employee share-based compensation expense related to the Performance Plan of $39 .

Tangible Stockholder Return Pla

Tangible Stockholder Return Plan	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Tangible Shareholder Return Plan	Share-Based Compensation 2016 Stock Plan During the three months ended March 31, 2019 , the Company continued to administer and grant awards under the 2016 Incentive Award Plan (the “2016 Plan”), the Company’s only active equity incentive plan. Certain of the Company’s outstanding and exercisable stock options remain subject to the terms of the Company’s 2008 Stock Plan (the “2008 Plan”), which is the predecessor to the 2016 Plan and became inactive upon adoption of the 2016 Plan effective September 20, 2016. On August 16, 2018, the board of directors approved an amendment to the 2016 Plan, subject to stockholder approval, to increase the number of shares reserved under the 2016 Plan by 1,000,000 and to increase the award limit on the maximum aggregate number of shares of the Company’s common stock that may be granted to any one person during any calendar year from 250,000 to 1,000,000 shares of the Company’s common stock. All other material terms of the 2016 Plan otherwise remain unchanged. Stock Appreciation Rights On August 8, 2018 , the Company entered into an employment agreement with G. Kelly Martin (the “Employment Agreement”). The Employment Agreement provided for 1,000,000 SARs granted on a contingent basis that shall be considered irrevocably forfeited and voided in full if the Company fails to obtain stockholder approval for an amendment to the 2016 Plan, described above. If such approval is not obtained, the Company will pay Mr. Martin the cash equivalent of the value of the SARs. The SARs entitle Mr. Martin to a payment (in cash, shares of common stock or a combination of both) equal to the fair market value of one share of the Company’s common stock on the date of exercise less the exercise price of $3.80 per share. The SARs will vest in full on February 1, 2020. The SARs will be deemed automatically exercised and settled as of February 1, 2020, provided Mr. Martin remains continuously employed with the Company through such date unless vesting is otherwise expressly accelerated pursuant to the SAR Agreement. Due to the cash settlement feature of the SAR grant, subject to stockholder approval, these share-based payment awards should be classified as liabilities and the amount of compensation cost recognized must be based on the fair value of those liabilities. Therefore, the obligation is recorded as a liability on the Company’s condensed consolidated balance sheet at the estimated fair value on the date of issuance and is re-valued each subsequent reporting period with adjustments to the fair value recognized as share-based compensation expense in the condensed consolidated statements of operations. During the three months ended March 31, 2019 , the Company recorded employee share-based compensation expense related to the SARs of $7 . There was no share-based compensation expense related to SARs during the three months ended March 31, 2018 . In addition, the corresponding obligation is recorded within other long-term liabilities on the Company’s condensed consolidated balance sheet as of March 31, 2019 . Inducement Grants In May 2018, the Company awarded nonstatutory stock options to purchase an aggregate of 100,500 shares of common stock to newly-hired employees, not previously employees or directors of the Company, as inducements material to the individuals’ entering into employment with the Company within the meaning of Nasdaq Listing Rule 5635(c)(4) (the “Inducement Grants”). The Inducement Grants have a grant date of May 31, 2018 and an exercise price of $3.15 per share. The Inducement Grants were awarded outside of the Company’s 2016 Plan, pursuant to Nasdaq Listing Rule 5635(c)(4), but have terms and conditions generally consistent with the Company’s 2016 Plan and vest over three years, with one-third of the award vesting on each annual anniversary of the employee’s employment commencement date, subject to the employee’s continued service as an employee through the vesting period. Stock Compensation Expense During the three months ended March 31, 2019 and 2018 , the Company recorded employee share-based compensation expense for equity-based awards of $214 and $887 , respectively. Total share-based compensation expense for equity-based awards included in the condensed consolidated statements of operations and comprehensive loss is as follows: Three Months Ended March 31, 2019 2018 Research and development $ 61 $ 420 General and administrative 153 467 $ 214 $ 887 Stock option activity for the three months ended March 31, 2019 is as follows: Shares Subject to Outstanding Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Options outstanding as of December 31, 2018 1,671,666 $ 5.42 Options granted 147,500 1.31 Options forfeited (160,810 ) 4.64 Options exercised (12,999 ) 0.76 Options outstanding as of March 31, 2019 1,645,357 $ 5.17 7.37 $ — As of March 31, 2019 , there were a total of 1,645,357 stock options outstanding, including 100,500 inducement grants awarded in May 2018. In addition, there were 703,519 shares available for future issuance under the 2016 Plan as of March 31, 2019 . Tangible Stockholder Return Plan Performance Plan On August 2, 2018, the Company’s board of directors approved and established the Tangible Stockholder Return Plan, which is a performance-based long-term incentive plan (the “Performance Plan”). The Performance Plan was effective immediately upon approval and expires on March 1, 2022 . The Performance Plan covers all employees, including the Company’s executive officers, consultants and other persons deemed eligible by the Company’s compensation committee. The core underlying metric of the Performance Plan is the achievement of two share price goals for the Company’s common stock, which if achieved, would represent measurable increases in stockholder value. The Performance Plan is tiered, with two separate tranches, each of which has a distinct share price target (measured as the average publicly traded share price of the Company’s common stock on the Nasdaq stock exchange for a 30 consecutive trading day period) that will, if achieved, trigger a distinct fixed bonus pool. The share price target for the first tranche and related bonus pool are $11.17 per share and $25,000 , respectively. The share price target for the second tranche and related bonus pool are $25.45 per share and $50,000 , respectively. The compensation committee has discretion to distribute the bonus pool related to each tranche among eligible participants by establishing individual minimum bonus amounts before, as well as by distributing the remainder of the applicable pool after, the achievement of each tranche specific share price target. Otherwise, if the Company does not achieve one or both related share price targets, as defined, no portion of the bonus pools will be paid. The Performance Plan provides for the distinct fixed bonus pools to be paid in the form of cash. However, the compensation committee has discretion to pay any bonus due under the Performance Plan in the form of cash, shares of the Company’s common stock or a combination thereof, provided that the Company’s stockholders have approved the reservation of shares of the Company’s common stock for such payment. The Performance Plan permits the compensation committee to make bonus awards subject to varying payment terms, including awards that vest and are payable immediately upon achieving an applicable share price target as well as awards that pay over an extended period (either with or without ongoing employment requirements). The Performance Plan contemplates that no bonus award payments will be delayed beyond 24 months for named executive officers or more than 12 months for all other participants. For purposes of determining whether a share price target has been met, the share price targets will be adjusted in the event of any stock splits, cash dividends, stock dividends, combinations, reorganizations, reclassifications or similar events. In the event of a change in control, as defined in the Performance Plan, during the term of the Performance Plan, a performance bonus pool will be generated based on pro-rata progress toward achievement of the applicable share price target through the date of the change in control. The Company has concluded that the Performance Plan is within the scope of ASC 718 , Compensation — Stock Compensation as the underlying plan obligations are based on the potential attainment of certain market share price targets of the Company’s common stock. Any awards under the Performance Plan would be payable, at the discretion of the Company’s compensation committee following the achievement of the applicable share price target, in cash, shares of the Company’s common stock, or a combination thereof, provided that, prior to any payment in common stock, the Company’s stockholders have approved the reservation of shares of the Company’s common stock for such payment. ASC 718 requires that a liability-based award should be classified as a liability on the Company’s condensed consolidated balance sheets and the amount of compensation cost recognized should be based on the fair value of the liability. When a liability-based award includes both a service and market condition, the market condition is taken into account when determining the appropriate method to estimate fair value and the compensation cost is amortized over the estimated service period. Therefore, the liability associated with the Performance Plan obligation is recorded within other long-term liabilities on the Company’s condensed consolidated balance sheets at the estimated fair value on the date of issuance and is re-valued each subsequent reporting period end. The Company recognizes share-based compensation expense within operating expenses in the condensed consolidated statements of operations, including adjustments to the fair value of the liability-based award, on a straight-line basis over the requisite service period. The fair value of obligations under the Performance Plan are estimated using a Monte Carlo simulation approach. The Company’s common stock price is simulated under the Geometric Brownian Motion framework under each simulation path. The other assumptions for the Monte Carlo simulation include the risk-free interest rate, estimated volatility and the expected term. Expected stock price volatility is based on the actual historical volatility of a group of comparable publicly traded companies observed over a historical period equal to the expected remaining life of the plan. The fair value of the underlying common stock is the published closing market price on the Nasdaq Global Market as of each reporting date. The risk-free interest rate is based on the U.S. Treasury yield curve in effect on the date of valuation equal to the remaining expected life of the plan. The dividend yield percentage is zero because the Company does not currently pay dividends, nor does it intend to do so during the expected term of the plan. The expected life of bonus awards under the Performance Plan is assumed to be equivalent to the remaining contractual term based on the estimated service period including the service inception date of the plan participants and the contractual end of the Performance Plan. During the three months ended March 31, 2019 , the Company recorded employee share-based compensation expense related to the Performance Plan of $39 .

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Members of the Company’s board of directors held 782,083 shares of the Company’s common stock as of March 31, 2019 and December 31, 2018 . In June 2017, G. Kelly Martin was appointed as the Company’s Interim Chief Executive Officer before being named as the Company’s Chief Executive Officer in April 2018. Mr. Martin continues to serve as a member of the Company’s board of directors and previously served as chief executive officer of Malin Corporation plc until October 1, 2017. Malin Corporation plc is the parent company of Malin Life Sciences Holdings Limited (“Malin”), which beneficially owns approximately 10% of the Company’s outstanding common stock. Two of the Company’s directors during 2018 were also affiliated with Malin. Sean Murphy, who resigned from the Company’s board in September 2018, was an executive officer and a director of Malin, and an executive vice president of Malin Corporation plc. In addition, Robert A. Ingram, the Company’s executive chairman of the board, was also a director of Malin Corporation plc until July 2018. Cilatus BioPharma During the three months ended March 31, 2019 and 2018 , the Company incurred costs of $94 and $198 , respectively, in relation to a development and manufacturing consulting agreement with Cilatus BioPharma AG, which is majority-owned by Malin Corporation plc. These costs are expensed as incurred and are classified as research and development expenses in the accompanying condensed consolidated statements of operations and comprehensive loss. Estimated fees remaining under the current statements of work are approximately $140 , and are expected to be incurred throughout the remainder of 2019. Health Decisions On October 25, 2018, the Company announced the formation of a dedicated women’s health business unit as well as a foundational collaboration with Health Decisions, Inc. (“Health Decisions”). Health Decisions is a full-service contract research organization specializing in clinical studies of therapeutics for women’s health indications. The Company’s women’s health business unit is led by Paula Brown Stafford, who also is a shareholder and serves on the board of directors of Health Decisions.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Royalty and Milestone Payments Purchase Agreement with Reedy Creek Investments LLC On April 29, 2019, the Company entered into a royalty and milestone payments purchase agreement (the “Purchase Agreement”) with Reedy Creek Investments LLC (“Reedy Creek”), pursuant to which Reedy Creek provided funding to the Company in an initial amount of $25,000 , which the Company will use primarily to pursue the development, regulatory approval and commercialization (including through out-license agreements and other third party arrangements) activities for SB206, a topical anti-viral gel being developed for the treatment of molluscum contagiosum, and advancing programmatically such activities with respect to SB204, a once-daily, topical monotherapy being developed for the treatment of acne vulgaris, and SB414, a topical cream-based product candidate being developed for the treatment of atopic dermatitis. Reedy Creek will also provide additional funding to the Company of $10,000 contingent upon the achievement by the Company of SB206 clinical trial success, defined as (i) the achievement, no later than March 31, 2020, of statistically significant rates of complete clearance of lesions for molluscum contagiosum in humans at week 12 in each of the two Phase 3 clinical trials or any other primary endpoint required or accepted by the FDA for the SB206 product, or (ii) equivalent achievement (as agreed upon by the parties). Pursuant to the Purchase Agreement, the Company will pay Reedy Creek ongoing quarterly payments, calculated based on an applicable percentage per product of any upfront fees, milestone payments, royalty payments or equivalent payments received by the Company pursuant to any out-license agreement for SB204, SB206 or SB414 in the United States, Mexico or Canada, net of any upfront fees, milestone payments, royalty payments or equivalent payments paid by the Company to third parties pursuant to any agreements under which the Company has in-licensed intellectual property with respect to such products in the United States, Mexico or Canada. The applicable percentage used for determining the ongoing quarterly payments for each product ranges from 10% for SB206 to 20% for SB204 and SB414, provided that the applicable percentage for each product will be 25% for fees or milestone payments received by the Company (but not royalty payments received by the Company) until Reedy Creek has received payments under the Purchase Agreement equal to the total funding amount provided by Reedy Creek under the Purchase Agreement. If the Company decides to commercialize any product on its own following regulatory approval, as opposed to commercializing through an out-license agreement or other third party arrangement, the Company will be obligated to pay Reedy Creek a low single digits royalty on net sales of such products. Reedy Creek beneficially owns approximately 15% of the Company’s outstanding common stock and approximately 3.9 million warrants, all of which was acquired during the Company’s public offering of common stock and accompanying warrants in January 2018. Accordingly, Reedy Creek is a related party of the Company. The aforementioned transaction was evaluated and approved pursuant to the Company’s existing related party transactions policy. The terms of the Purchase Agreement were determined by the Company’s audit committee to be negotiated at arms-length and approximate market terms between third parties. Development Funding and Royalties Agreement with Ligand Pharmaceuticals Incorporated On May 4, 2019, the Company entered into a development funding and royalties agreement (the “Funding Agreement”) with Ligand Pharmaceuticals Incorporated (“Ligand”), pursuant to which Ligand provided funding to the Company of $12,000 , which the Company will use to pursue the development and regulatory approval of SB206, a topical anti-viral gel being developed for the treatment of molluscum contagiosum. Pursuant to the Funding Agreement, the Company will pay Ligand up to $20,000 in milestone payments upon the achievement by the Company of certain regulatory and commercial milestones associated with SB206 or any product that incorporates or uses NVN1000, the active pharmaceutical ingredient for the Company’s clinical stage product candidates, for the treatment of molluscum contagiosum. In addition to the milestone payments, the Company will pay Ligand tiered royalties ranging from 7% to 10% based on aggregate annual net sales of such products in the United States, Mexico or Canada.

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation and Unaudited Interim Condensed Consolidated Financial Statements	Unaudited Interim Condensed Consolidated Financial Statements The accompanying interim condensed consolidated financial statements and the related footnote disclosures are unaudited. These unaudited condensed consolidated financial statements have been prepared in accordance with U.S. GAAP and applicable rules and regulations of the Securities and Exchange Commission’s (“SEC”) Rule 10-01 of Regulation S-X for interim financial information. The condensed consolidated financial statements were prepared on the same basis as the audited consolidated financial statements and in the opinion of management, reflect all adjustments of a normal, recurring nature that are necessary for the fair statement of the Company’s financial position and its results of operations and cash flows. The results of operations for interim periods are not necessarily indicative of the results expected for the full fiscal year or any future period. These interim financial statements should be read in conjunction with the financial statements and notes for the year ended December 31, 2018 set forth in the Company’s Annual Report on Form 10-K filed with the SEC on March 27, 2019 . The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The December 31, 2018 year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. Additionally, the Company’s independent registered public accounting firm report for the December 31, 2018 financial statements included an explanatory paragraph indicating that there is substantial doubt about the Company’s ability to continue as a going concern.
Basis of Consolidation	Basis of Consolidation The accompanying condensed consolidated financial statements reflect the operations of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Liquidity and Ability to Continue as a Going Concern	Liquidity and Ability to Continue as a Going Concern The Company’s condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The accompanying condensed consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from uncertainty related to the Company’s ability to continue as a going concern. The Company has evaluated principal conditions and events that may raise substantial doubt about its ability to continue as a going concern within one year from the date that these financial statements are issued. The Company identified the following conditions: • The Company has reported a net loss in all fiscal periods since inception and, as of March 31, 2019 , the Company had an accumulated deficit of $ 180,066 . • As described in Note 13—Subsequent Events, in April 2019 and May 2019 the Company entered into (i) a royalty and milestone payments purchase agreement with a stockholder providing $25,000 of immediate funding, with an additional $10,000 contingent upon achieving successful top-line results of the SB206 Phase 3 clinical trials no later than March 31, 2020; and (ii) a development funding and royalties agreement with a corporate partner providing $12,000 of immediate funding. The Company believes that its existing cash and cash equivalents, expected contractual payments to be received in connection with previous licensing agreements, and the addition of the $25,000 and $12,000 received through these funding transactions will (i) provide the Company with adequate liquidity to fund its planned operating needs into the first quarter of 2020, including through expected top-line results of the Phase 3 molluscum clinical program targeted in the first quarter of 2020, or before; and (ii) into the second quarter of 2020, if paired with the potential $10,000 funding contingent upon achieving successful top-line results of the SB206 Phase 3 clinical trials no later than March 31, 2020. As of May 7, 2019, the total of $37,000 of immediate funds related to these two agreements had been received by the Company. • The Company’s primary use of cash is to fund its operating expenses, which consist principally of research and development expenditures necessary to advance its product candidates. The Company has evaluated its expected, probable future cash flow needs and has determined that it expects to incur substantial losses in the future as it conducts planned operating activities. As such, the Company has concluded that the prevailing conditions and ongoing liquidity risks it faces raise substantial doubt about its ability to continue as a going concern. The Company will need substantial additional funding to continue its operating activities and make further advancements in its drug development programs beyond those planned in 2019 and certain activities in the first half of 2020. The failure of the Company to obtain sufficient funds on acceptable terms, or the failure to trigger the $10,000 contingent payment under the Company’s royalty and milestone payments purchase agreement, could have a material adverse effect on the Company’s business and cause the Company to alter or reduce its planned operating activities, including but not limited to delaying, reducing, terminating or eliminating planned product candidate development activities, to conserve its cash and cash equivalents. The Company intends to secure additional capital as needed from non-dilutive sources, including partnerships, collaborations, licensing, grants or other strategic relationships, or through equity or debt financings, which could result in dilution.
Use of Estimates	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 and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from these estimates.
Restricted Cash	Restricted Cash Restricted cash of $539 as of March 31, 2019 and December 31, 2018 , consisted of funds maintained in a separate deposit account to secure a letter of credit for the benefit of the lessor of facility space leased by the Company.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted average shares outstanding during the period, without consideration of common stock equivalents. Diluted net loss per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are anti-dilutive for all periods presented.
Segment and Geographic Information	Segment and Geographic Information The Company has determined that it operates in one segment. The Company uses its nitric oxide-based technology to develop product candidates. The Chief Executive Officer, who is the Company’s chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. The Company has only had limited revenue since its inception, but all revenue was derived from licensing agreements originating in the United States. All of the Company’s long-lived assets are maintained in the United States.
Recently Issued Accounting Standards	Recently Issued Accounting Standards Accounting Pronouncements Adopted In February 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) . This guidance revises the accounting related to leases by requiring lessees to recognize a lease liability and a right-of-use asset for all leases. The new lease guidance also simplifies the accounting for sale and leaseback transactions. In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases and ASU 2018-11, Leases (Topic 842): Targeted Improvements, and in March 2019, the FASB issued ASU 2019-01, Leases (Topic 842): Codification Improvements. These additional ASUs were issued to provide expanded or clarifying guidance associated with the application of certain principles . Under the guidance, lessees are required to recognize assets and lease liabilities on the balance sheet for most leases including operating leases and provide enhanced disclosures. There are optional practical expedients that a company may elect to apply. The guidance was effective for the Company beginning in its first quarter of 2019. The Company adopted Topic 842 as of January 1, 2019 using the modified alternative retrospective transition method and initially applied the transition provisions as of January 1, 2019. This transition method allowed the Company to continue to apply the legacy guidance in ASC 840 for periods prior to 2019 and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit as of the date of adoption. The Company elected the package of transition practical expedients, which, among other things, allowed the Company to keep the historical lease classifications and not have to reassess the lease classification and initial direct costs for any existing or expired leases as of the date of adoption. The Company also made an accounting policy election to apply the short-term lease exception, which allows the Company to exclude leases with an initial term of twelve months or less from the consolidated balance sheets. Lease expense for leases with an initial term of twelve months or less will be recognized over the lease term, similar to the accounting treatment under ASC 840. As a result of the adoption of Topic 842, the Company derecognized $10,557 of building assets (property, plant and equipment), and the $7,998 facility financing obligation associated with the previously existing build-to-suit arrangement related to its sole corporate and manufacturing facility. The Company also capitalized leasehold improvements and ROU assets of $5,885 and $1,827 , respectively, and recorded lease liabilities for operating leases totaling $6,786 , as of January 1, 2019. The capitalized leasehold improvement assets recorded as part of the adoption of Topic 842 were previously included within the derecognized building asset as part of the previous build-to-suit arrangement. The Company also recognized an increase of $714 to accumulated deficit related to its de-recognition of its previously recorded build-to-suit arrangement. The impact of the adoption of this guidance is non-cash in nature and did not affect the Company’s cash flows. See Note 7—Commitments and Contingencies, for additional information related to the adoption of Topic 842. In June 2018, the FASB issued ASU No. 2018-07 Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting . This guidance simplifies the accounting for non-employee share-based payment transactions by expanding the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. Under the new standard, most of the guidance on stock compensation payments to non-employees would be aligned with the requirements for share-based payments granted to employees. This standard is effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within those annual reporting periods, with early adoption permitted. This ASU was effective for the Company as of January 1, 2019. The adoption of this new accounting guidance did not have a material impact on the Company’s condensed consolidated financial statements. Accounting Pronouncements Being Evaluated In August 2018, the FASB issued ASU No. 2018-13 Fair Value Measurement (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement. This guidance is intended to improve the effectiveness of disclosure requirements on fair value measurements in Topic 820. The new standard modifies certain disclosure requirements and will be effective for annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact of adoption of this ASU and does not expect the adoption of this new standard to have a material impact on its condensed consolidated financial statements. In October 2018, the FASB issued ASU No. 2018-17 Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. This guidance is intended to improve the accounting for variable interest entities and whether the entity should be consolidated. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim reporting periods within those annual reporting periods, with early adoption permitted. The Company is evaluating the impact of adoption of this ASU and does not currently expect the adoption of this new standard to have a material impact on its condensed consolidated financial statements.
Leases	The Company has elected to separate lease components (fixed rent payments) with non-lease components (common-area maintenance costs) on our real estate assets. Fixed lease payments on operating leases are recognized over the expected term of the lease on a straight-line basis. Variable lease expenses that are not considered fixed are expensed as incurred. Fixed and variable lease expense on operating leases is recognized within operating expenses within our condensed consolidated statements of operations. We have elected the short-term lease exemption and, therefore, do not recognize a ROU asset or corresponding liability for lease arrangements with an original term of 12 months or less. Prior to January 1, 2019, the Company applied the accounting guidance in ASC 840, Leases , to its lease agreements. The leases were reviewed for classification as operating or capital leases. For operating leases, rent was recognized on a straight-line basis over the lease period. For capital leases, the Company recorded the leased asset with a corresponding liability and amortized the asset over the lease term. Payments were recorded as reductions to the liability with an appropriate interest charge recorded based on the then-outstanding remaining liability. The Company considered the nature of the renovations and the Company’s involvement during the construction period of previously leased office space to determine if it is considered to be the owner of the construction project during the construction period. If the Company determined that it was the owner of the construction project, it was required to capitalize the fair value of the building as well as the construction costs incurred, including capitalized interest, on its consolidated balance sheet along with a corresponding financing liability (“build-to-suit accounting”). Upon completion of the construction of the facility under a build-to-suit lease, the Company assessed whether the circumstances qualified for sales recognition under the sale-leaseback accounting guidance. If the lease met the sale-leaseback criteria, the Company would remove the asset and related financial obligation from the balance sheet and evaluate the lease for treatment as a capital or operating lease. If upon completion of construction, the project did not meet the sale-leaseback criteria, the leased property was treated as an asset financing for financial reporting purposes. The portion of the facility financing obligation representing the principal that was to be repaid in the following 12 months was classified as a current liability in the condensed consolidated balance sheets, with the remaining portion of the obligation classified as a noncurrent liability. Beginning January 1, 2019, the Company applies the accounting guidance in ASC 842, Leases. As such, the Company assesses all arrangements, that convey the right to control the use of property, plant and equipment, at inception, to determine if it is, or contains, a lease based on the unique facts and circumstances present in that arrangement. For those leases identified, the Company determines the lease classification, recognition, and measurement at the lease commencement date. For arrangements that contain a lease the Company: (i) identifies lease and non-lease components; (ii) determines the consideration in the contract; (iii) determines whether the lease is an operating or financing lease; and (iv) recognizes lease Right of Use (“ROU”) assets and corresponding lease liabilities. Lease liabilities are recorded based on the present value of lease payments over the expected lease term. The corresponding ROU asset is measured from the initial lease liability, adjusted by (i) accrued or prepaid rents; (ii) remaining unamortized initial direct costs and lease incentives; and (iii) any impairments of the ROU asset. The interest rate implicit in the Company’s lease contracts is typically not readily determinable and as such, the Company uses its incremental borrowing rate based on the information available at the lease commencement date, which represents an internally developed rate that would be incurred to borrow, on a collateralized basis, over a similar term, an amount equal to the lease payments in a similar economic environment. The Company elected the package of transition practical expedients, which, among other things, allowed the Company to keep the historical lease classifications and not have to reassess the lease classification for any existing leases as of the date of adoption. The Company also made an accounting policy election to apply the short-term lease exception, which allows the Company to exclude leases with an initial term of twelve months or less from the consolidated balance sheets.
Fair Value of Financial Instruments	The fair value of the common stock warrants is estimated using a valuation model that approximates a Monte Carlo simulation model, which takes into consideration the probability of a fundamental transaction occurring during the contractual term of the warrants. Due to the Company’s limited historical stock price data, the Company estimates stock price volatility based on the actual historical volatility of a group of comparable publicly traded companies observed over a historical period equal to the expected life of the warrant.
Share-based Compensation	Due to the cash settlement feature of the SAR grant, subject to stockholder approval, these share-based payment awards should be classified as liabilities and the amount of compensation cost recognized must be based on the fair value of those liabilities. Therefore, the obligation is recorded as a liability on the Company’s condensed consolidated balance sheet at the estimated fair value on the date of issuance and is re-valued each subsequent reporting period with adjustments to the fair value recognized as share-based compensation expense in the condensed consolidated statements of operations. ASC 718 requires that a liability-based award should be classified as a liability on the Company’s condensed consolidated balance sheets and the amount of compensation cost recognized should be based on the fair value of the liability. When a liability-based award includes both a service and market condition, the market condition is taken into account when determining the appropriate method to estimate fair value and the compensation cost is amortized over the estimated service period. Therefore, the liability associated with the Performance Plan obligation is recorded within other long-term liabilities on the Company’s condensed consolidated balance sheets at the estimated fair value on the date of issuance and is re-valued each subsequent reporting period end. The Company recognizes share-based compensation expense within operating expenses in the condensed consolidated statements of operations, including adjustments to the fair value of the liability-based award, on a straight-line basis over the requisite service period. The fair value of obligations under the Performance Plan are estimated using a Monte Carlo simulation approach. The Company’s common stock price is simulated under the Geometric Brownian Motion framework under each simulation path. The other assumptions for the Monte Carlo simulation include the risk-free interest rate, estimated volatility and the expected term. Expected stock price volatility is based on the actual historical volatility of a group of comparable publicly traded companies observed over a historical period equal to the expected remaining life of the plan. The fair value of the underlying common stock is the published closing market price on the Nasdaq Global Market as of each reporting date. The risk-free interest rate is based on the U.S. Treasury yield curve in effect on the date of valuation equal to the remaining expected life of the plan. The dividend yield percentage is zero because the Company does not currently pay dividends, nor does it intend to do so during the expected term of the plan. The expected life of bonus awards under the Performance Plan is assumed to be equivalent to the remaining contractual term based on the estimated service period including the service inception date of the plan participants and the contractual end of the Performance Plan.

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Anti-dilutive Securities Excluded from Calculation of Weighted Average Common Shares Outstanding	The following securities, presented on a common stock equivalent basis, have been excluded from the calculation of weighted average common shares outstanding for the three months ended March 31, 2019 and 2018 because the effect is anti-dilutive due to the net loss reported in each of those periods. All share amounts presented in the table below represent the total number outstanding as of the end of each period. In addition, as described in Note 10—Share-Based Compensation, the Company’s board granted 1,000,000 stock appreciation rights (“SARs”) on a contingent basis in the third quarter of 2018. These securities are subject to stockholder approval and therefore are not considered outstanding as of March 31, 2019; however, if such securities were to be approved by stockholders, their effect would be anti-dilutive. March 31, 2019 2018 Warrants to purchase common stock associated with January 2018 public offering (Note 9) 10,000,000 10,000,000 Stock options outstanding under the 2008 and 2016 Plans (Note 10) 1,544,857 1,560,134 Inducement options outstanding (Note 10) 100,500 —

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Schedule of Contract Assets and Contract Liabilities	The following table presents the Company’s contract assets and contract liabilities balances for the periods indicated. Contract Asset Contract Liability Net Deferred Revenue December 31, 2018 $ 17,790 $ 24,757 $ 6,967 March 31, 2019 $ 13,330 $ 23,657 $ 10,327 Short-term Deferred Revenue Long-term Deferred Revenue Net Deferred Revenue December 31, 2018 $ 4,401 $ 2,566 $ 6,967 March 31, 2019 $ 4,401 $ 5,926 $ 10,327

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Components of Property and Equipment	Property and equipment consisted of the following: March 31, December 31, Computer equipment $ 575 $ 577 Furniture and fixtures 312 312 Laboratory equipment 7,494 7,442 Office equipment 400 400 Building related to facility lease obligation — 10,557 Leasehold improvements 7,053 1,168 Property and equipment, gross 15,834 20,456 Less: Accumulated depreciation and amortization (4,177 ) (4,588 ) Total property and equipment, net $ 11,657 $ 15,868

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments	At January 1, 2019, maturities of operating lease liabilities over each of the next five years and thereafter were as follows: Operating Leases 2019 $ 1,170 2020 1,205 2021 1,241 2022 1,278 2023 1,317 Thereafter 3,467 Total minimum lease payments $ 9,678 Less imputed interest (2,871 ) Total lease liability $ 6,807

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Future Issuance	The Company had reserved shares of common stock for future issuance as follows: March 31, 2019 December 31, 2018 Outstanding stock options (Note 10) 1,645,357 1,671,666 Warrants to purchase common stock issued in January 2018 Offering (Note 9) 10,000,000 10,000,000 For possible future issuance under 2016 Stock Plan (Note 10) 703,519 699,376 12,348,876 12,371,042

Warrants (Tables)

Warrants (Tables)	3 Months Ended
	Mar. 31, 2019
Warrants and Rights Note Disclosure [Abstract]
Summary of Warrant Liability Measured at Fair Value on a Recurring Basis	The following table presents the Company’s warrant liability measured at fair value on a recurring basis as of March 31, 2019 and December 31, 2018 : March 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Liabilities: Warrant liability $ — $ — $ 1,628 $ 1,628 Total liabilities at fair value $ — $ — $ 1,628 $ 1,628 December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Liabilities: Warrant liability $ — $ — $ 1,240 $ 1,240 Total liabilities at fair value $ — $ — $ 1,240 $ 1,240
Summary of Fair Value Assumptions for Common Stock Warrants	The inputs to the valuation model that approximates a Monte Carlo simulation model are presented below. March 31, 2019 December 31, 2018 Estimated dividend yield — — Expected volatility 81.21%-100% 77.74%-100% Risk-free interest rate 2.21 % 2.46 % Expected term (years) 2.78 3.02 Fair value per share of common stock underlying the warrant $ 0.96 $ 0.83 Warrant exercise price $ 4.66 $ 4.66
Summary of Change in Fair Value of Warrant Liability, Valued Using Significant Unobservable Level 3 Inputs	The following table summarizes the change in the fair value of the warrant liability, which is valued using significant unobservable Level 3 inputs, for the three months ended March 31, 2019 and 2018 : Three Months Ended March 31, 2019 2018 Beginning Balance $ 1,240 $ — Issuance $ — $ 17,806 Revaluations Included In Earnings $ 388 $ (3,558 ) Exercises $ — $ — Expirations $ — $ — Ending Balance $ 1,628 $ 14,248

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation Expenses	Total share-based compensation expense for equity-based awards included in the condensed consolidated statements of operations and comprehensive loss is as follows: Three Months Ended March 31, 2019 2018 Research and development $ 61 $ 420 General and administrative 153 467 $ 214 $ 887
Summary of Stock Option Activity	Stock option activity for the three months ended March 31, 2019 is as follows: Shares Subject to Outstanding Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Options outstanding as of December 31, 2018 1,671,666 $ 5.42 Options granted 147,500 1.31 Options forfeited (160,810 ) 4.64 Options exercised (12,999 ) 0.76 Options outstanding as of March 31, 2019 1,645,357 $ 5.17 7.37 $ —

Organization and Significant _4

Organization and Significant Accounting Policies - Additional Information (Details)	Jan. 09, 2018USD ($)$ / sharesshares	Mar. 31, 2019USD ($)segment	Sep. 30, 2018shares	Mar. 31, 2018USD ($)	May 07, 2019USD ($)	May 04, 2019USD ($)	Apr. 29, 2019USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
Organization And Significant Accounting Policies [Line Items]
Accumulated deficit		$ 180,066,000							$ 172,327,000
Common stock issued through public offering (in shares) | shares	10,000,000
Public offering price per share (in USD per share) | $ / shares	$ 3.80
Warrant exercise price (in USD per share) | $ / shares	$ 4.66
Warrants expiration period	4 years
Shelf registration and public offering, costs capitalized		49,000							49,000
Restricted cash		$ 539,000							539,000
SARs granted (in shares) | shares			1,000,000
Number of segment | segment		1
Revenue		$ 1,100,000		$ 658,000
Property and equipment, gross		15,834,000							20,456,000
Facility lease obligation		0							7,998,000
Right-of-use assets capitalized		1,833,000							0
Lease liabilities capitalized								$ 6,807,000
Increase to accumulated deficit		714,000
Retained Earnings
Organization And Significant Accounting Policies [Line Items]
Increase to accumulated deficit		714,000
Leasehold improvements
Organization And Significant Accounting Policies [Line Items]
Property and equipment, gross		7,053,000							$ 1,168,000
ASU 2016-02 (Topic 842)
Organization And Significant Accounting Policies [Line Items]
Facility lease obligation								7,998,000
Right-of-use assets capitalized								1,827,000
Lease liabilities capitalized								6,786,000
ASU 2016-02 (Topic 842) | Retained Earnings
Organization And Significant Accounting Policies [Line Items]
Increase to accumulated deficit								714,000
ASU 2016-02 (Topic 842) | Building Related to Facility Lease Obligation
Organization And Significant Accounting Policies [Line Items]
Property and equipment, gross								10,557,000
ASU 2016-02 (Topic 842) | Leasehold improvements
Organization And Significant Accounting Policies [Line Items]
Property and equipment, gross								$ 5,885,000
Amended Sato Agreement
Organization And Significant Accounting Policies [Line Items]
Revenue		$ 1,100,000		$ 649,000
Maximum
Organization And Significant Accounting Policies [Line Items]
Warrants issued (in shares) | shares	10,000,000
Shelf Registration
Organization And Significant Accounting Policies [Line Items]
Shelf registration and public offering, costs capitalized	$ 110,000
January 2018 Offering
Organization And Significant Accounting Policies [Line Items]
Common stock issued through public offering (in shares) | shares	10,000,000
Public offering price per share (in USD per share) | $ / shares	$ 3.8
Warrant exercise price (in USD per share) | $ / shares	$ 4.66
Net proceeds from public offering	$ 35,194,000
Underwriting discounts and commissions and offering expenses	2,806,000
Shelf registration and public offering, costs capitalized	$ 370,000
January 2018 Offering | Maximum
Organization And Significant Accounting Policies [Line Items]
Warrants issued (in shares) | shares	10,000,000
Subsequent Event
Organization And Significant Accounting Policies [Line Items]
Immediate funding					$ 37,000,000	$ 12,000,000	$ 25,000,000
Additional funding potentially receivable							$ 10,000,000

Organization and Significant _5

Organization and Significant Accounting Policies - Summary of Anti-dilutive Securities Excluded from Calculation of Weighted Average Common Shares Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Warrants to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	10,000,000	10,000,000
Stock Options | 2008 Stock Plan and 2016 Stock Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	1,544,857	1,560,134
Stock Options | Inducement Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	100,500	0

KNOW Bio, LLC (Details)

KNOW Bio, LLC (Details)	Oct. 13, 2017USD ($)oncovirus	Dec. 29, 2015	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 30, 2015
Collaborative Arrangements Transactions [Line Items]
Milestone and royalty payments			$ 0	$ 0
KNOW Bio
Collaborative Arrangements Transactions [Line Items]
Percentage of outstanding member interests of KNOW Bio distributed to stockholders					100.00%
Written notice to terminate, period			90 days
Right to sublicense, term		3 years
Option term for development and commercialization of products	3 years
Upfront license agreement payment due upon execution	$ 250,000
KNOW Bio | Maximum
Collaborative Arrangements Transactions [Line Items]
Number of other specified oncoviruses | oncovirus	4

Research and Development Lice_2

Research and Development Licenses (Details) - USD ($)	Mar. 31, 2019	Jun. 27, 2012
Licensing Agreements
Research And Development Licenses [Line Items]
Accrual for future payments	$ 0
UNC License Agreement
Research And Development Licenses [Line Items]
Potential regulatory and commercial milestones payable under agreement		$ 425,000

Licensing Arrangements (Details

Licensing Arrangements (Details) - Amended Sato Agreement

Mar. 14, 2019JPY (¥)

Mar. 14, 2019USD ($)

Oct. 23, 2018JPY (¥)

Oct. 23, 2018USD ($)

Oct. 05, 2018USD ($)

Jan. 19, 2017JPY (¥)

Jan. 19, 2017USD ($)

Jan. 12, 2017JPY (¥)

Jan. 12, 2017USD ($)

Mar. 31, 2019

Sep. 13, 2019JPY (¥)

Feb. 14, 2019JPY (¥)

Dec. 31, 2018JPY (¥)

Dec. 31, 2018USD ($)

Oct. 05, 2018JPY (¥)

Jan. 12, 2017USD ($)

Collaborative Arrangements Transactions [Line Items]

Upfront payment receivable

¥ 1,250,000,000

Upfront payment installments

¥ 500,000,000

250,000,000

Payment received under license agreement

¥ 500,000,000

$ 4,460,000

¥ 250,000,000

$ 2,224,000

¥ 1,250,000,000

$ 10,813,000

¥ 1,250,000,000

$ 10,813,000

Aggregate development and regulatory milestone payments potentially receivable under license agreement

2,750,000,000

1,750,000,000

Aggregate Phase 1 trial milestone payment term under license agreement

250,000,000

¥ 250,000,000

$ 2,162,000

$ 2,162,000

Aggregate becoming payable upon earlier of specified future dates or achievement of milestone events

1,000,000,000

Aggregate commercial milestone payments potentially receivable under license agreement

¥ 900,000,000

¥ 3,900,000,000

License agreement additional term

2 years

Maximum preclinical studies amount | $

$ 1,000,000

Written notice to terminate, period

120 days

120 days

Written notice to terminate due to material breach, term

60 days

60 days

Upfront fee refundable in event of termination | $

$ 0

Scenario, Forecast

Collaborative Arrangements Transactions [Line Items]

Upfront payment installments

¥ 500,000,000

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details)	Mar. 14, 2019JPY (¥)	Mar. 14, 2019USD ($)	Oct. 23, 2018JPY (¥)	Oct. 23, 2018USD ($)	Jan. 19, 2017JPY (¥)	Jan. 19, 2017USD ($)	Jan. 12, 2017JPY (¥)	Jan. 12, 2017USD ($)	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Sep. 13, 2019JPY (¥)	Feb. 14, 2019JPY (¥)	Dec. 31, 2018JPY (¥)	Dec. 31, 2018USD ($)	Oct. 05, 2018JPY (¥)	Jan. 12, 2017USD ($)
Disaggregation of Revenue [Line Items]
Performance obligations under long-term contracts unsatisfied									$ 10,327,000
Total revenue									1,100,000	$ 658,000
License and collaboration revenue
Disaggregation of Revenue [Line Items]
Total revenue									1,100,000	649,000
Research and development services revenue
Disaggregation of Revenue [Line Items]
Total revenue									0	9,000
Amended Sato Agreement
Disaggregation of Revenue [Line Items]
Maximum preclinical studies amount								$ 1,000,000
Payment received under license agreement	¥ 500,000,000	$ 4,460,000	¥ 250,000,000	$ 2,224,000	¥ 1,250,000,000	$ 10,813,000	¥ 1,250,000,000	$ 10,813,000
Milestone payment received following initiation of Phase 1 trial							250,000,000						¥ 250,000,000	$ 2,162,000		$ 2,162,000
Upfront payment receivable | ¥															¥ 1,250,000,000
Upfront payment installments | ¥												¥ 500,000,000			250,000,000
Aggregate becoming payable upon earlier of specified future dates or achievement of milestone events | ¥															1,000,000,000
Potential future sales-based milestone payments | ¥							¥ 900,000,000								¥ 3,900,000,000
Total revenue									1,100,000	649,000
Amended Sato Agreement | License and collaboration revenue
Disaggregation of Revenue [Line Items]
Total revenue									1,100,000	649,000
KNOW Bio Services Agreement | Research and development services revenue
Disaggregation of Revenue [Line Items]
Total revenue									$ 0	$ 9,000
Scenario, Forecast | Amended Sato Agreement
Disaggregation of Revenue [Line Items]
Upfront payment installments | ¥											¥ 500,000,000

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Contract Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract asset	$ 13,330	$ 17,790
Contract liability, gross	23,657	24,757
Contract liability	10,327	6,967
Deferred revenue, current portion	4,401	4,401
Deferred revenue, net of current portion	$ 5,926	$ 2,566

Revenue Recognition - Performan

Revenue Recognition - Performance Obligations, Expected Timing of Satisfaction (Details)	Mar. 31, 2019	Oct. 04, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation percentage	19.00%
Estimated performance period	12 months
Amended Sato Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2017-02-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Estimated performance period	7 years 6 months	5 years

Property and Equipment, Net - C

Property and Equipment, Net - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 15,834	$ 20,456
Less: Accumulated depreciation and amortization	(4,177)	(4,588)
Total property and equipment, net	11,657	15,868
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	575	577
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	312	312
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,494	7,442
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	400	400
Building related to facility lease obligation
Property, Plant and Equipment [Line Items]
Property and equipment, gross	0	10,557
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,053	$ 1,168

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 503	$ 401

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) ft² in Thousands, $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended	15 Months Ended
	Jul. 31, 2018USD ($)ft²	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Mar. 31, 2019USD ($)officer	Jan. 01, 2019USD ($)	Aug. 31, 2015ft²
Commitments And Contingencies [Line Items]
Weighted average discount rate, operating lease liabilities		9.85%			9.85%
Weighed average remaining lease term, operating leases		7 years 3 months			7 years 3 months
Property and equipment, gross		$ 15,834		$ 20,456	$ 15,834
Facility lease obligation		0		7,998	0
Interest expense		0	$ 262
Right-of-use assets capitalized		1,833		0	1,833
Lease liabilities capitalized						$ 6,807
Increase to accumulated deficit		714			714
Right of use assets obtained in exchange for lease liabilities		1,827
November 2018 Restructuring
Commitments And Contingencies [Line Items]
Accrued severance costs		82			$ 82
Total employee severance costs		306
Severance costs expensed during the period		61
Three Former Officers
Commitments And Contingencies [Line Items]
Number of former officers | officer					3
Severance expenses		878	332
Stock compensation expense related to accelerated vesting of former officers stock options		0	212
Retained Earnings
Commitments And Contingencies [Line Items]
Increase to accumulated deficit		714			$ 714
ASU 2016-02 (Topic 842)
Commitments And Contingencies [Line Items]
Facility lease obligation						7,998
Right-of-use assets capitalized						1,827
Lease liabilities capitalized						6,786
ASU 2016-02 (Topic 842) | Retained Earnings
Commitments And Contingencies [Line Items]
Increase to accumulated deficit						714
Accrued compensation | Three Former Officers
Commitments And Contingencies [Line Items]
Accrued severance costs		621			621
Building Related to Facility Lease Obligation | ASU 2016-02 (Topic 842)
Commitments And Contingencies [Line Items]
Property and equipment, gross						10,557
Leasehold improvements
Commitments And Contingencies [Line Items]
Property and equipment, gross		$ 7,053		1,168	$ 7,053
Leasehold improvements | ASU 2016-02 (Topic 842)
Commitments And Contingencies [Line Items]
Property and equipment, gross						$ 5,885
Primary Facility Lease
Commitments And Contingencies [Line Items]
Rentable square feet of facility space | ft²							51,000
Optional term of extending lease agreement		5 years			5 years
Current contractual base rent payments per month		$ 95
Percentage of increase in annual rental payments		3.00%
Grounds rent expense per month		$ 8
Facility lease obligation				7,998
Interest expense			261
Primary facility lease rent expense		$ 157	$ 42
Primary Facility Lease | Sublease Agreement
Commitments And Contingencies [Line Items]
Rentable square feet of facility space | ft²	6,400
Sublease term	3 years
Monthly rental income	$ 12
Primary Facility Lease | Other Accrued Expenses
Commitments And Contingencies [Line Items]
Accrued interest				$ 41
Primary Facility Lease | Building Related to Facility Lease Obligation
Commitments And Contingencies [Line Items]
Property and equipment, estimated useful life				25 years
Property and equipment, gross				$ 10,557

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Maturities of Operating Lease Liabilities (Details) $ in Thousands	Jan. 01, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
2019	$ 1,170
2020	1,205
2021	1,241
2022	1,278
2023	1,317
Thereafter	3,467
Total minimum lease payments	9,678
Less imputed interest	(2,871)
Total lease liability	$ 6,807

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Capital stock, shares authorized (in shares)	210,000,000
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, par value (in USD per share)	$ 0.0001
Preferred stock, shares outstanding (in shares)	0	0
Common stock, shares outstanding (in shares)	26,069,734	26,056,735

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Details) - shares	Mar. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Common stock shares reserved for future issuance (in shares)	12,348,876	12,371,042
2016 Stock Plan
Class of Stock [Line Items]
Common stock shares reserved for future issuance (in shares)	703,519	699,376
Warrants to Purchase Common Stock
Class of Stock [Line Items]
Common stock shares reserved for future issuance (in shares)	10,000,000	10,000,000
Outstanding stock options
Class of Stock [Line Items]
Common stock shares reserved for future issuance (in shares)	1,645,357	1,671,666

Warrants - Additional Informati

Warrants - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 09, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Class of Warrant or Right [Line Items]
Common stock issued through public offering (in shares)	10,000,000
Public offering price per share (in USD per share)	$ 3.80
Warrant exercise price (in USD per share)	$ 4.66
Warrants expiration period	4 years
Warrant exercise limitation, maximum beneficial ownership percentage, current	4.99%
Warrant exercise limitation, maximum beneficial ownership percentage, if elected by holder	9.99%
Beneficial ownership percentage, exception to exercise limitation provision	10.00%
Fundamental transaction voting securities acquired threshold	50.00%
Maximum volatility rate used to derive Black-Scholes Value in event of fundamental transaction	100.00%
Warrants exercised (in shares)		0	0
Change in fair value of warrant liability		$ 388	$ (3,558)
Maximum
Class of Warrant or Right [Line Items]
Warrants issued (in shares)	10,000,000
Warrant liability
Class of Warrant or Right [Line Items]
Warrant fair value per share (in USD per share)		$ 0.16		$ 0.12

Warrants - Summary of Warrant L

Warrants - Summary of Warrant Liability Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	$ 1,628	$ 1,240
Warrant liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	1,628	1,240
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Warrant liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	0	0
Significant Other Observable Inputs (Level 2) | Warrant liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	1,628	1,240
Significant Unobservable Inputs (Level 3) | Warrant liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	$ 1,628	$ 1,240

Warrants - Summary of Fair Valu

Warrants - Summary of Fair Value Assumptions for Common Stock Warrants (Details)	Mar. 31, 2019$ / shares	Dec. 31, 2018$ / shares	Jan. 09, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (years)			4 years
Significant Unobservable Inputs (Level 3) | Estimated dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0	0
Significant Unobservable Inputs (Level 3) | Expected volatility | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.8121	0.7774
Significant Unobservable Inputs (Level 3) | Expected volatility | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	1	1
Significant Unobservable Inputs (Level 3) | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.0221	0.0246
Significant Unobservable Inputs (Level 3) | Expected term (years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (years)	2 years 9 months 11 days	3 years 7 days
Significant Unobservable Inputs (Level 3) | Fair value per share of common stock underlying the warrant (in USD per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.96	0.83
Significant Unobservable Inputs (Level 3) | Warrant exercise price (in USD per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	4.66	4.66

Warrants - Summary of Change in

Warrants - Summary of Change in Fair Value of Warrant Liability, Valued Using Significant Unobservable Level 3 Inputs (Details) - Significant Unobservable Inputs (Level 3) - Warrant liability - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 1,240	$ 0
Issuance	0	17,806
Revaluations Included In Earnings	388	(3,558)
Exercises	0	0
Expirations	0	0
Ending Balance	$ 1,628	$ 14,248

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 16, 2018	Aug. 08, 2018	May 31, 2018	Sep. 30, 2016	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employment agreement, number of SARs granted on a contingent basis (in shares)						1,000,000
SAR exercise price (in USD per share)		$ 3.80
Number of options granted to employees (in shares)					147,500
Share-based compensation expense for equity-based awards					$ 214		$ 887
Stock options outstanding (in shares)					1,645,357			1,671,666
CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employment agreement, number of SARs granted on a contingent basis (in shares)		1,000,000
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee share-based compensation expense					$ 7		$ 0
Inducement Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SAR exercise price (in USD per share)			$ 3.15
Number of options granted to employees (in shares)			100,500
Stock options vesting period			3 years
Stock options outstanding (in shares)					100,500
Inducement Grants | Vesting Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage					33.33%
Inducement Grants | Vesting Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage					33.33%
Inducement Grants | Vesting Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage					33.33%
2016 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional awards to be granted under the plan (in shares)	1,000,000
Maximum aggregate shares to be awarded to one person (in shares)	1,000,000			250,000
Shares available for future issuance (in shares)					703,519

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Share-based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense for equity-based awards	$ 214	$ 887
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense for equity-based awards	61	420
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense for equity-based awards	$ 153	$ 467

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Shares Subject to Outstanding Options
Options outstanding (in shares) | shares	1,671,666
Options granted (in shares) | shares	147,500
Options forfeited (in shares) | shares	(160,810)
Options exercised (in shares) | shares	(12,999)
Options outstanding (in shares) | shares	1,645,357
Weighted-Average Exercise Price Per Share
Options outstanding (in USD per share) | $ / shares	$ 5.42
Options granted (in USD per share) | $ / shares	1.31
Options forfeited (in USD per share) | $ / shares	4.64
Options exercised (in USD per share) | $ / shares	0.76
Options outstanding (in USD per share) | $ / shares	$ 5.17
Weighted- Average Remaining Contractual Term (in years)
Options outstanding	7 years 4 months 13 days
Aggregate Intrinsic Value
Options outstanding | $	$ 0

Tangible Stockholder Return P_2

Tangible Stockholder Return Plan (Details)	Aug. 02, 2018USD ($)tranche$ / shares	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 214,000	$ 887,000
Performance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated dividend yield		0.00%
Share-based compensation expense		$ 39,000
Performance Plan | Deferred Bonus
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of tranches | tranche	2
Number of consecutive trading days	30 days
Share price target, first tranche (in USD per share) | $ / shares	$ 11.17
Bonus pool, first tranche	$ 25,000,000
Share price target, second tranche (in USD per share) | $ / shares	$ 25.45
Bonus pools, second tranche	$ 50,000,000
Executive Officer | Performance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Bonus award payment term		24 months
Employees And Consultants | Performance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Bonus award payment term		12 months

Related Party Transactions (Det

Related Party Transactions (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019USD ($)shares	Mar. 31, 2018USD ($)	Dec. 31, 2018directorshares
Related Party Transaction [Line Items]
Common stock, number of shares held (in shares) | shares	26,069,734		26,056,735
Research and development expense	$ 4,827	$ 6,335
Board Members
Related Party Transaction [Line Items]
Common stock, number of shares held (in shares) | shares	782,083		782,083
Malin
Related Party Transaction [Line Items]
Number of directors also affiliated with related party during year | director			2
Malin | Novan, Inc.
Related Party Transaction [Line Items]
Beneficial ownership percentage	10.00%
Cilatus BioPharma AG
Related Party Transaction [Line Items]
Research and development expense	$ 94	$ 198
Estimated fees remaining under current statement of work	$ 140

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) shares in Millions	May 07, 2019	May 04, 2019	Apr. 29, 2019	Mar. 31, 2019
Reedy Creek Investments LLC
Subsequent Event [Line Items]
Warrants owned (in shares)				3.9
Reedy Creek Investments LLC | Novan, Inc.
Subsequent Event [Line Items]
Beneficial ownership percentage				15.00%
Subsequent Event
Subsequent Event [Line Items]
Immediate funding	$ 37,000,000	$ 12,000,000	$ 25,000,000
Additional funding potentially receivable			10,000,000
Subsequent Event | Ligand Pharmaceuticals Incorporated
Subsequent Event [Line Items]
Immediate funding		12,000,000
Potential regulatory and commercial milestones payable under agreement		$ 20,000,000
Subsequent Event | Minimum | Ligand Pharmaceuticals Incorporated
Subsequent Event [Line Items]
Tiered royalties, percentage		7.00%
Subsequent Event | Maximum | Ligand Pharmaceuticals Incorporated
Subsequent Event [Line Items]
Tiered royalties, percentage		10.00%
Subsequent Event | Reedy Creek Investments LLC
Subsequent Event [Line Items]
Immediate funding			25,000,000
Additional funding potentially receivable			$ 10,000,000
Initial percentage of fees and milestone to determine quarterly payments per agreement			25.00%
Subsequent Event | Reedy Creek Investments LLC | SB206
Subsequent Event [Line Items]
Percentage used to determine ongoing quarterly payments per agreement			10.00%
Subsequent Event | Reedy Creek Investments LLC | SB204 And SB414
Subsequent Event [Line Items]
Percentage used to determine ongoing quarterly payments per agreement			20.00%