Aptinyx (APTX) 10-Q 10 Aug 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 05, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-38535
Entity Registrant Name	Aptinyx Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-4626057
Entity Address, Address Line One	909 Davis Street
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Evanston
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60201
City Area Code	847
Local Phone Number	871-0377
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	APTX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		67,715,718
Entity Central Index Key	0001674365
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 129,226	$ 141,028
Restricted cash	179	179
Accounts receivable		257
Prepaid expenses and other current assets	4,372	8,140
Total current assets	133,777	149,604
Other assets	92	92
Property and equipment, net	299	910
Total assets	134,168	150,606
Current liabilities:
Accounts payable	434	1,209
Accrued expenses and other current liabilities	2,948	3,374
Total current liabilities	3,382	4,583
Other long-term liabilities	30	114
Total liabilities	3,412	4,697
Commitments and contingencies (see Note 10)
Stockholders' equity:
Preferred stock, $0.01 par value, 10,000 shares authorized and no shares issued and outstanding as of June 30, 2021 and December 31, 2020
Common stock, $0.01 par value, 150,000 shares authorized as of June 30, 2021 and December 31, 2020, 67,716 and 63,257 issued and outstanding as of June 30, 2021 and December 31, 2020	677	633
Additional paid-in capital	377,125	358,277
Accumulated deficit	(247,046)	(213,001)
Total stockholders' equity	130,756	145,909
Total liabilities and stockholders' equity	$ 134,168	$ 150,606

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Jun. 30, 2021	Dec. 31, 2020
Condensed Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	150,000	150,000
Common stock, shares issued	67,716	63,257
Common stock, shares outstanding	67,716	63,257

Condensed Statements of Operati

Condensed Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Collaboration revenue		$ 490	$ 1,000	$ 1,308
Type of Revenue [Extensible List]			aptx:CollaborationRevenueMember	aptx:CollaborationRevenueMember
Operating expenses:
Research and development	$ 14,796	8,365	$ 25,110	$ 19,420
General and administrative	5,070	4,770	10,046	9,669
Total operating expenses	19,866	13,135	35,156	29,089
Loss from operations	(19,866)	(12,645)	(34,156)	(27,781)
Other income	47	128	111	554
Net loss and comprehensive loss	$ (19,819)	$ (12,517)	$ (34,045)	$ (27,227)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.29)	$ (0.27)	$ (0.51)	$ (0.61)
Weighted-average number of common shares outstanding, basic and diluted (in shares)	67,381	45,680	66,716	44,757

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (34,045)	$ (27,227)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	450	211
Stock-based compensation expense	5,133	4,834
Changes in operating assets and liabilities:
Prepaid expenses and other assets	3,692	1,889
Accounts receivable	257	(46)
Accounts payable	(775)	(60)
Accrued expenses and other liabilities	(467)	(946)
Net cash used in operating activities	(25,755)	(21,345)
Cash flows from investing activities:
Purchases of property and equipment		(35)
Proceeds from sale of property and equipment	121
Net cash provided by (used in) investing activities	121	(35)
Cash flows from financing activities:
Proceeds from stock options exercised	133	473
Repurchase of shares for tax withholdings	(912)
Proceeds from public offering, net of underwriters' discounts		33,672
Proceeds from at the market offering, net of sales commission	14,615	4,668
Payment of offering costs	(4)	(404)
Net cash provided by financing activities	13,832	38,409
Net (decrease) increase in cash, cash equivalents and restricted cash	(11,802)	17,029
Cash, cash equivalents and restricted cash, at beginning of period	141,299	99,194
Cash, cash equivalents and restricted cash, at end of period	$ 129,497	116,223
Supplemental disclosure of non-cash investing and financing activities:
Offering costs not yet paid		12
Property and equipment in accounts payable		$ 38

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity - USD ($) $ in Thousands	Follow-on Public OfferingCommon stock	Follow-on Public OfferingAdditional paid-in capital	Follow-on Public Offering	ATM OfferingCommon stock	ATM OfferingAdditional paid-in capital	ATM Offering	Common stock	Additional paid-in capital	Accumulated deficit	Total
Stockholders' (deficit) equity beginning balance at Dec. 31, 2019							$ 337	$ 263,922	$ (162,948)	$ 101,311
Stockholders' (deficit) equity shares beginning balance at Dec. 31, 2019							33,739,000
Stockholders' (Deficit) Equity Rollforward
Issuance of common stock upon vesting of restricted stock (in shares)							23,000
Issuance of common stock	$ 117	$ 33,225	$ 33,342	$ 12	$ 4,563	$ 4,575
Issuance of common stock (in shares)	11,692,000			1,193,000
Stock-based compensation								4,834		4,834
Issuance of common stock upon exercise of stock options							$ 2	471		473
Issuance of common stock upon exercise of stock options (in shares)							203,000
Net loss									(27,227)	(27,227)
Stockholders' (deficit) equity ending balance at Jun. 30, 2020							$ 468	307,015	(190,175)	117,308
Stockholders' (deficit) equity shares ending balance at Jun. 30, 2020							46,850,000
Stockholders' (deficit) equity beginning balance at Mar. 31, 2020							$ 455	299,721	(177,658)	122,518
Stockholders' (deficit) equity shares beginning balance at Mar. 31, 2020							45,546,000
Stockholders' (Deficit) Equity Rollforward
Issuance of common stock upon vesting of restricted stock (in shares)							12,000
Issuance of common stock				$ 12	4,563	4,575
Issuance of common stock (in shares)				1,193,000
Stock-based compensation								2,503		2,503
Issuance of common stock upon exercise of stock options							$ 1	228		229
Issuance of common stock upon exercise of stock options (in shares)							99,000
Net loss									(12,517)	(12,517)
Stockholders' (deficit) equity ending balance at Jun. 30, 2020							$ 468	307,015	(190,175)	117,308
Stockholders' (deficit) equity shares ending balance at Jun. 30, 2020							46,850,000
Stockholders' (deficit) equity beginning balance at Dec. 31, 2020							$ 633	358,277	(213,001)	$ 145,909
Stockholders' (deficit) equity shares beginning balance at Dec. 31, 2020							63,257,000			63,257,000
Stockholders' (Deficit) Equity Rollforward
Issuance of common stock upon vesting of restricted stock							$ 11	(11)
Issuance of common stock upon vesting of restricted stock (in shares)							1,089,000
Repurchase of shares for tax withholdings							$ (3)	(909)		$ (912)
Repurchase of shares for tax withholdings (in shares)							(347,000)
Issuance of common stock				$ 36	$ 14,502	$ 14,538
Issuance of common stock (in shares)				3,630,000		3,629,458
Stock-based compensation								5,133		5,133
Issuance of common stock upon exercise of stock options								133		133
Issuance of common stock upon exercise of stock options (in shares)							87,000
Net loss									(34,045)	(34,045)
Stockholders' (deficit) equity ending balance at Jun. 30, 2021							$ 677	377,125	(247,046)	$ 130,756
Stockholders' (deficit) equity shares ending balance at Jun. 30, 2021							67,716,000			67,716,000
Stockholders' (deficit) equity beginning balance at Mar. 31, 2021							$ 669	375,499	(227,227)	$ 148,941
Stockholders' (deficit) equity shares beginning balance at Mar. 31, 2021							66,930,000
Stockholders' (Deficit) Equity Rollforward
Issuance of common stock upon vesting of restricted stock							$ 11	(11)
Issuance of common stock upon vesting of restricted stock (in shares)							1,084,000
Repurchase of shares for tax withholdings							$ (3)	(902)		(905)
Repurchase of shares for tax withholdings (in shares)							(345,000)
Stock-based compensation								2,478		2,478
Issuance of common stock upon exercise of stock options								61		61
Issuance of common stock upon exercise of stock options (in shares)							47,000
Net loss									(19,819)	(19,819)
Stockholders' (deficit) equity ending balance at Jun. 30, 2021							$ 677	$ 377,125	$ (247,046)	$ 130,756
Stockholders' (deficit) equity shares ending balance at Jun. 30, 2021							67,716,000			67,716,000

Condensed Statements of Stock_2

Condensed Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Sales commissions and other offering costs		$ 4	$ 404
Follow-on Public Offering
Discount and other offering costs			1,733
ATM Offering
Sales commissions and other offering costs	$ 237	$ 529	$ 237

Organization

Organization	6 Months Ended
	Jun. 30, 2021
Organization
Organization	1. Organization Description of business Aptinyx Inc. (the “Company” or “Aptinyx”) was incorporated in Delaware on June 24, 2015 and maintains its headquarters in Evanston, Illinois. Aptinyx is a clinical-stage biopharmaceutical company focused on the discovery, development, and commercialization of novel, proprietary, synthetic small molecules for the treatment of brain and nervous system disorders. Aptinyx has a platform for discovering proprietary compounds that work through a novel mechanism: modulation of N-methyl-D-aspartate receptors (“NMDAr”), which are vital to normal and effective brain and nervous system functions. This mechanism has applicability across numerous nervous system disorders. Liquidity and capital resources On July 1, 2019, the Company entered into a Sales Agreement with Cowen and Company, LLC (“Cowen”) pursuant to which the Company may offer and sell shares of its common stock with an aggregate offering price of up to $50.0 million under an “at the market” offering program (the “ATM Offering”). The Sales Agreement provides that Cowen will be entitled to a sales commission equal to 3.0% of the gross sales price per share of all shares sold under the ATM Offering. To date, the Company has sold an aggregate of 5,120,940 shares at a weighted-average price of $3.99 per share for net proceeds of $20.4 million after deducting sales commission and other offering expenses, including 3,629,458 shares for net proceeds of $14.5 million during the six months ended June 30, 2021. ​ On January 14, 2020, the Company completed a follow-on ​ On October 26, 2020, the Company completed a follow-on ​ As of June 30, 2021, the Company had cash and cash equivalents of $129.2 million, which the Company believes will be sufficient to funds its planned operations for a period of at least twelve months from the date of issuance of these condensed financial statements.

Summary of significant accounti

Summary of significant accounting policies	6 Months Ended
	Jun. 30, 2021
Summary of significant accounting policies
Summary of significant accounting policies	2. Basis of presentation The condensed financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. The accompanying condensed financial statements reflect all adjustments consisting of normal, recurring adjustments that are necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods presented. Interim results are not necessarily indicative of results for a full year. Accordingly, these condensed financial statements should be read in conjunction with the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (the “Annual Report”) filed with the SEC on March 24, 2021. From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”), or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial statements upon adoption. Under the Jumpstart Our Business Startups Act of 2012, as amended (the “JOBS Act”), the Company meets the definition of an emerging growth company, and has elected the extended transition period for complying with new or revised accounting standards, which delays the adoption of these accounting standards until they would apply to private companies. Use of estimates The condensed financial statements are prepared in conformity with GAAP. This process requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Risk and uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of: the impact of COVID-19 on future clinical study results, the scope, timing, rate of progress, and expense of the Company’s ongoing as well as any additional preclinical studies, clinical studies, and other research and development activities, clinical study enrollment rate or design, the manufacturing of the Company’s product candidates, significant and changing government regulation, and the timing and receipt of any regulatory approvals. A novel strain of coronavirus (COVID-19) was first identified in December 2019, and subsequently declared a global pandemic by the World Health Organization on March 11, 2020. As a result of the outbreak, many companies have experienced disruptions in their operations and in markets served. On March 27, 2020, the Company suspended patient enrollment for certain ongoing Phase 2 clinical studies, including its NYX-2925 studies in painful diabetic peripheral neuropathy and fibromyalgia and its NYX-483 study in Parkinson’s disease cognitive impairment and dementia with Lewy bodies. The Company re-initiated enrollment in its NYX-2925 study in fibromyalgia in September 2020, in its NYX-2925 study in painful diabetic peripheral neuropathy in January 2021, and in its NYX-483 study in Parkinson’s disease cognitive impairment and dementia with Lewy bodies in March 2021. The Company has initiated some and may take additional temporary precautionary measures intended to help ensure the well-being of its employees and minimize business disruption. The Company considered the impact of COVID-19 on the assumptions and estimates used and determined that there were no material adverse impacts on the Company’s results of operations and financial position as of and for the six months ended June 30, 2021. The full extent of the future impacts of COVID-19 on the Company’s operations is uncertain. A prolonged outbreak could have a material adverse impact on financial results and business operations of the Company, including the availability of capital, timing and ability of the Company to complete certain clinical studies, and other efforts required to advance the development of its targets. Significant accounting policies The Company’s significant accounting policies are described in Note 3, “Summary of significant accounting policies,” in the Annual Report. There have been no material changes to the significant accounting policies during the six months ended June 30, 2021. Recently issued accounting pronouncement In February 2016, the FASB issued ASU No. 2016-02, Leases definition of a lease. The new standard includes a short-term lease exception for leases with a term of 12 months or less, as part of which a lessee can make an accounting policy election not to recognize lease assets and lease liabilities. Lessees will continue to differentiate between finance leases (previously referred to as capital leases) and operating leases using classification criteria that are substantially similar to the previous guidance. The new standard will be effective for the Company for annual reporting periods beginning after December 15, 2021 and interim periods within fiscal years beginning after December 15, 2022, and early adoption is permitted. The Company anticipates that the adoption of this standard will have an impact on its balance sheet due to the recognition of right-of-use assets and lease liabilities; however, the Company is currently evaluating the impact that the adoption of ASU 2016-02 may have on its condensed financial statements.

Supplemental financial informat

Supplemental financial information	6 Months Ended
	Jun. 30, 2021
Supplemental financial information
Supplemental financial information	3. Supplemental financial information Cash, cash equivalents and restricted cash Cash and cash equivalents consist of cash and, if applicable, highly liquid investments with an original maturity of three months or less when purchased. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets that sum to the total of the same such amounts shown in the condensed statements of cash flows (in thousands). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ 2021 2020 Cash and cash equivalents ​ $ 129,226 ​ $ 141,028 ​ Short-term and long-term restricted cash ​ 271 ​ 271 ​ Total cash, cash equivalents, and restricted cash shown in the statements of cash flows ​ $ 129,497 ​ $ 141,299 ​ ​ Prepaid expenses and other current assets ​ Prepaid expenses and other current assets consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ 2021 2020 Prepaid clinical $ 1,669 ​ $ 6,052 Prepaid insurance ​ ​ 88 ​ ​ 1,177 ​ Prepaid manufacturing costs ​ ​ 2,308 ​ ​ 613 ​ Other prepaid expenses and current assets 307 ​ 298 Total prepaid expenses and other current assets $ 4,372 ​ $ 8,140 ​ Accrued expenses and other current liabilities ​ Accrued expenses and other current liabilities consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ 2021 2020 Employee-related expenses ​ $ 1,135 ​ $ 2,039 ​ Development costs and sponsored research ​ 728 ​ 897 ​ Clinical trials ​ 656 ​ 195 ​ Other ​ 429 ​ 243 ​ Total accrued expenses and other current liabilities ​ $ 2,948 ​ $ 3,374 ​ ​

Research collaboration agreemen

Research collaboration agreement with Allergan	6 Months Ended
	Jun. 30, 2021
Research collaboration agreement with Allergan
Research collaboration agreement with Allergan	4. Research collaboration agreement with Allergan On July 24, 2015, the Company entered into a Research Collaboration Agreement (“RCA”) with Naurex Inc., a subsidiary of Allergan plc (“Allergan”), which became a wholly owned subsidiary of AbbVie Inc. in May 2020. The RCA was focused on the research and discovery of small molecules that modulate NMDArs. The collaboration was supervised by a Joint Steering Committee (“JSC”) comprising an equal number of representatives from both the Company and Allergan. Under the terms of the agreement, the RCA terminated upon the earlier of (i) 180 days after a predetermined anniversary of the effective date of the RCA and (ii) the date on which Allergan exercised the last of three options to acquire molecules from a pool of eligible compounds, in both cases (clauses (i) and (ii)) subject to potential extension if and as required for the Company to transfer to Allergan information and technology related to compounds that were licensed by Allergan. The jointly funded research activities and option exercise period under the RCA, including the associated payments by Allergan to the Company, came to their contractual conclusions in accordance with the agreement in August 2020 and February 2021, respectively. Under the terms of the agreement, Allergan was to pay the Company $1.0 million for each option exercised by Allergan. On February 23, 2021, Allergan exercised its option to acquire exclusive rights to develop and commercialize AGN-281705 within a predefined set of indications. For the six months ended June 30, 2021, the Company recognized the $1.0 million non-refundable milestone payment within collaboration revenue in the statements of operations as there were no remaining performance obligations associated with the optioned compound. The Company concluded that Allergan meets the definition of a customer, and therefore concluded that the RCA represents a contract with a customer that falls within the scope of ASC 606. Performance obligations The Company identified the following promised goods or services within the RCA: ​ ● Research Licenses – the Company provides access to exclusive licenses under all of the Company’s NMDAr technologies, during the research term for the sole purpose of conducting research and development activities (the “Research Licenses”). Historically, the Company’s licenses have held no value to the customer on a standalone basis, as the research compounds were in the early discovery phase and required the Company’s expertise for further development. Accordingly, the Research Licenses are not considered distinct. ● Research and Development Services – the Company provided research and development services that were performed on behalf of, or with, Allergan (the “Research and Development Services”). As discussed within Research Licenses above, the Company’s licenses have historically held no value without the specialized Research and Development Services. As the Company generally only provides Research and Development Services for internally generated small molecules that modulate NMDArs which require a license to be utilized by a third party, the Research and Development Services are not considered distinct. ● Joint Steering Committee – the Company actively participated in a joint steering committee, which allowed the Company and its collaboration partner to direct the progression and prioritization of the joint discovery programs. As the JSC would not occur or benefit the customer without the use of the Research Licenses and the related Research and Development Services, and given the Company’s proprietary knowledge of the Research Licenses and the NMDAr technologies, this is not considered distinct. ​ The Company also evaluated whether the option granted to the customer to acquire additional goods or services represented a material right at contract inception. Upon Allergan’s exercise of one of its options, the Company was obligated to transfer control of all intellectual property relating to the optioned compound to Allergan, after which the Company has no further interest in, or continuing involvement with, such optioned compound. The Company evaluated the customer options for material rights, that is, whether the option was to acquire additional goods or services for free or at a discount, and concluded that the options are priced, at contract inception, at standalone selling price. Consequently, the customer options do not represent a performance obligation at the outset of the arrangement since they are contingent upon the option exercise which is outside of the Company’s control. The Company has concluded that there is a single combined performance obligation (comprising the Research Licenses, Research and Development Services, and participation in the JSC) which is satisfied over time, as the Research and Development Services are performed. The exercise of the option to acquire exclusive rights to develop and commercialize AGN-241751 or AGN-281705 are not considered a performance obligation until the time of option exercise. Transaction price ​ The RCA included both fixed and variable consideration. Fixed payments, such as contractually defined fees per full-time employee (“FTE”), were included in the transaction price at contract inception, while variable consideration, such as reimbursement for Research and Development Services, were estimated and then evaluated for constraints upon inception of the contract and evaluated on a quarterly basis thereafter. Research and Development Services were updated for actual invoices. There were no capitalized costs associated with obtaining the contract. The Company used an input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. The Company used fixed FTE efforts and variable out-of-pocket costs as actual costs incurred relative to the annual budget research plan to measure progress towards fulfillment of the performance obligation. An input method of revenue recognition requires management to make estimates of costs to complete the Company’s performance obligations. In making such estimates, significant judgment is required to evaluate assumptions related to cost estimates. The cumulative effect of revisions to estimated costs to complete the Company’s performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated. The Company does not anticipate significant changes as the research plan is reviewed and adjusted annually and approved by the JSC. There are no significant financing components in the contract. The Company has determined that the option fee is representative of standalone selling price and concluded that it would recognize revenue for the option fee at a point in time, on the date of exercise, due to the significant uncertainty of whether or not Allergan would exercise the option. The Company recognizes the option fee at a point in time because control of the underlying intellectual property transfers to the customer, and the customer is able to use and benefit from the license. The Company has no further rights, interests, or remaining performance obligations associated with any optioned compound, once exercised. During the three months ended June 30, 2021 and 2020, the Company recorded expenses of $0.0 million and $1.0 million, respectively, for certain development activities in accordance with the terms of the RCA, of which 50% was reimbursed by Allergan. The Company received reimbursements of $0.0 million and $0.5 million during the three months ended June 30, 2021 and 2020, respectively.

Fair value measurements

Fair value measurements	6 Months Ended
	Jun. 30, 2021
Fair value measurements
Fair value measurements	5. Fair value measurements ASC 820, Fair Value Measurement ● Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities; ● Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly; and ● Level 3 inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying values reported in the Company’s balance sheets for cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued expenses are reasonable estimates of their fair values due to the short-term nature of these items. Assets measured at fair value as of June 30, 2021 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ ​ ​ 2021 Level 1 Level 2 Level 3 Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds, included in cash and cash equivalents ​ $ 128,693 ​ $ 128,693 ​ $ — ​ $ — Money market funds, included in restricted cash ​ ​ 179 ​ ​ 179 ​ — ​ — Money market funds, included in other assets ​ 92 ​ 92 ​ — ​ — ​ ​ $ 128,964 ​ $ 128,964 ​ $ — ​ $ — ​ Assets measured at fair value as of December 31, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ ​ ​ ​ 2020 Level 1 Level 2 Level 3 Assets ​ ​ ​ ​ Money market funds, included in cash and cash equivalents ​ $ 140,283 ​ $ 140,283 ​ $ — ​ $ — Money market funds, included in restricted cash ​ ​ 179 ​ ​ 179 ​ — ​ — Money market funds, included in other assets ​ ​ 92 ​ 92 ​ — ​ — ​ ​ $ 140,554 ​ $ 140,554 ​ $ — ​ $ — ​

Property and equipment, net

Property and equipment, net	6 Months Ended
	Jun. 30, 2021
Property and equipment, net
Property and equipment, net	​ 6. Property and equipment, net Property and equipment are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ ​ 2021 2020 Computer software and equipment ​ $ — $ 15 ​ Office equipment and furniture ​ 152 ​ 176 ​ Laboratory equipment ​ 401 ​ 1,801 ​ Leasehold improvements ​ 979 ​ 1,062 ​ Less accumulated depreciation ​ (1,233) ​ (2,144) ​ Property and equipment, net ​ $ 299 ​ $ 910 ​ ​ Depreciation expense was $0.1 million for each of the three months ended June 30, 2021 and 2020, respectively, and $0.5 million and $0.3 million for the six months ended June 30, 2021 and 2020, respectively. The Company disposed of certain laboratory equipment during the six months ended June 30, 2021 that were fully depreciated at the time of disposal.

Stock incentive plans

Stock incentive plans	6 Months Ended
	Jun. 30, 2021
Stock incentive plans
Stock incentive plans	7. Stock incentive plans On June 5, 2018, the Company’s stockholders approved the 2018 Stock Option and Incentive Plan (the “2018 Plan”), which became effective on June 20, 2018. The 2018 Plan provides for an annual increase, to be added on the first day of each fiscal year, of up to 4% of the Company’s outstanding shares of common stock as of the last day of the prior year. On January 1, 2021, Stock-based compensation expense Non-cash stock-based compensation expense recognized in the accompanying condensed statements of operations relating to stock options, restricted stock awards, and restricted stock units for the three and six months ended June 30, 2021 and 2020 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2021 2020 2021 2020 Research and development ​ $ 676 ​ $ 559 ​ $ 1,413 ​ $ 1,365 ​ General and administrative ​ 1,802 ​ 1,944 ​ 3,720 ​ 2,960 ​ Total stock‑based compensation expense ​ $ 2,478 ​ $ 2,503 ​ $ 5,133 ​ $ 4,325 ​ ​ Stock options The table below summarizes activity related to stock options (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ‑ ​ ​ ​ ​ ​ ​ Weighted ‑ ​ average ​ ​ ​ ​ ​ ​ ​ average ​ remaining ​ Aggregate ​ ​ ​ ​ exercise ​ contractual ​ intrinsic Options ​ Shares ​ price ​ term ​ value Outstanding, December 31, 2020 6,684 ​ $ 6.88 7.96 ​ $ 1,582 Granted 3,080 ​ 3.50 ​ Exercised ​ (87) ​ ​ 1.53 ​ ​ ​ ​ ​ Forfeited and canceled (189) ​ 6.67 ​ Outstanding, June 30, 2021 ​ 9,488 ​ $ 5.83 ​ 8.26 ​ $ 405 Vested and expected to vest at June 30, 2021 ​ 9,488 ​ $ 5.83 ​ 8.26 ​ $ 405 Exercisable at June 30, 2021 4,139 ​ $ 7.12 7.15 ​ $ 246 ​ During the six months ended June 30, 2021 and 2020, the Company granted 3.1 million and 2.4 million stock options, respectively and these options had a weighted-average grant-date fair value of $2.73 and $2.06 per share, respectively. The weighted-average grant-date fair value of options was determined using the Black-Scholes option-pricing model. The assumptions used in the Black-Scholes option-pricing model for options granted during the six months ended June 30, 2021 were similar to those as described in the Annual Report, except for the manner in which the expected volatility was determined. The expected volatility for the Company’s options granted during the six months ended June 30, 2021 is based on a weighted-average of the historical volatility of share values of publicly traded companies within the biotechnology industry which includes the historical volatility of the Company’s stock since the Company’s initial public offering. As of June 30, 2021, there was $17.4 million of total unrecognized stock-based compensation expense related to non-vested stock options which is expected to be recognized over a weighted-average period of 2.5 years. The options have a ten-year life and generally vest over a period of four years , subject to continuous employment. ​ Restricted stock units ​ In June 2020 and May 2019, the Company issued an aggregate of 205,200 and 1,183,400 restricted stock units, respectively, to employees. The restricted stock units issued in 2020 vest ten months from the date of grant. The restricted stock units issued in 2019 vest two years from the date of grant. The Company at any time may accelerate the vesting of the restricted stock units. Such shares are not accounted for as outstanding until they vest. ​ The table below summarizes activity related to restricted stock units (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ‑ ​ ​ ​ ​ average ​ ​ ​ ​ grant date ​ ​ ​ ​ fair value ​ ​ Shares ​ per share Unvested as of December 31, 2020 1,091 ​ $ 3.63 Issued ​ ​ $ ​ Vested (1,089) ​ ​ 3.63 Forfeited and canceled (2) ​ 3.63 Unvested as of June 30, 2021 — ​ $ — ​ ​ Non-cash restricted stock unit award expense recognized in the accompanying condensed statements of operations was $0.2 million and $0.5 million for the three months ended June 30, 2021 and 2020, respectively, and $0.8 million and $0.9 million for the six months ended June 30, 2021 and 2020, respectively. There were no unvested restricted stock units as of June 30, 2021.

Net loss per share

Net loss per share	6 Months Ended
	Jun. 30, 2021
Net loss per share
Net loss per share	8. Net loss per share Basic and diluted net loss per share attributable to common stockholders was calculated as follows for the three and six months ended June 30, 2021 and 2020 (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2021 2020 2021 2020 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to common stockholders ​ $ (19,819) ​ $ (12,517) ​ $ (34,045) ​ $ (27,227) ​ Denominator: ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding—basic and diluted ​ 67,381 ​ 45,680 ​ 66,716 ​ 44,757 ​ Net loss per share attributable to common stockholders—basic and diluted ​ $ (0.29) ​ $ (0.27) ​ $ (0.51) ​ $ (0.61) ​ ​ The following common stock equivalents outstanding as of June 30, 2021 and 2020, were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands): ​ ​ ​ ​ ​ ​ ​ As of ​ ​ June 30, ​ 2021 2020 Stock options issued and outstanding 9,488 6,680 Unvested restricted stock ​ — ​ 1,131 Total 9,488 7,811 ​

Income taxes

Income taxes	6 Months Ended
	Jun. 30, 2021
Income taxes
Income taxes	9. Income taxes Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, including its net operating losses. Based on its history of operating losses, the Company believes that it is more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets as of June 30, 2021 and December 31, 2020. ​ ​

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and contingencies
Commitments and contingencies	10. Commitments and contingencies Contingencies From time to time, the Company may be subject to occasional lawsuits, investigations, and claims arising out of the normal conduct of business. The Company has no significant pending or threatened litigation as of June 30, 2021. Indemnifications In the normal course of business, the Company enters into contracts that contain a variety of indemnifications with its employees, licensors, suppliers and service providers. Further, the Company indemnifies its directors and officers who are, or were, serving at the Company’s request in such capacities. The Company’s maximum exposure under these arrangements is unknown at June 30, 2021. The Company does not anticipate recognizing any significant losses relating to these arrangements. Leases The Company enters into various non-cancelable, operating lease agreements for its facilities and equipment in order to conduct its operations. The Company expenses rent on a straight-line basis over the life of the lease and has recorded deferred rent on the Company’s balance sheets within both accrued expenses and other current liabilities and other long-term liabilities. Total rent expense, inclusive of lease incentives, under all the operating lease agreements amounted to $0.2 million for each of the three months ended June 30, 2021 and 2020 and $0.4 million for each of the six months ended June 30, 2021 and 2020, respectively.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	6 Months Ended
	Jun. 30, 2021
Summary of significant accounting policies
Basis of presentation	Basis of presentation The condensed financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. The accompanying condensed financial statements reflect all adjustments consisting of normal, recurring adjustments that are necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods presented. Interim results are not necessarily indicative of results for a full year. Accordingly, these condensed financial statements should be read in conjunction with the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (the “Annual Report”) filed with the SEC on March 24, 2021. From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”), or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial statements upon adoption. Under the Jumpstart Our Business Startups Act of 2012, as amended (the “JOBS Act”), the Company meets the definition of an emerging growth company, and has elected the extended transition period for complying with new or revised accounting standards, which delays the adoption of these accounting standards until they would apply to private companies.
Use of estimates	Use of estimates The condensed financial statements are prepared in conformity with GAAP. This process requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.
Risk and uncertainties	Risk and uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of: the impact of COVID-19 on future clinical study results, the scope, timing, rate of progress, and expense of the Company’s ongoing as well as any additional preclinical studies, clinical studies, and other research and development activities, clinical study enrollment rate or design, the manufacturing of the Company’s product candidates, significant and changing government regulation, and the timing and receipt of any regulatory approvals. A novel strain of coronavirus (COVID-19) was first identified in December 2019, and subsequently declared a global pandemic by the World Health Organization on March 11, 2020. As a result of the outbreak, many companies have experienced disruptions in their operations and in markets served. On March 27, 2020, the Company suspended patient enrollment for certain ongoing Phase 2 clinical studies, including its NYX-2925 studies in painful diabetic peripheral neuropathy and fibromyalgia and its NYX-483 study in Parkinson’s disease cognitive impairment and dementia with Lewy bodies. The Company re-initiated enrollment in its NYX-2925 study in fibromyalgia in September 2020, in its NYX-2925 study in painful diabetic peripheral neuropathy in January 2021, and in its NYX-483 study in Parkinson’s disease cognitive impairment and dementia with Lewy bodies in March 2021. The Company has initiated some and may take additional temporary precautionary measures intended to help ensure the well-being of its employees and minimize business disruption. The Company considered the impact of COVID-19 on the assumptions and estimates used and determined that there were no material adverse impacts on the Company’s results of operations and financial position as of and for the six months ended June 30, 2021. The full extent of the future impacts of COVID-19 on the Company’s operations is uncertain. A prolonged outbreak could have a material adverse impact on financial results and business operations of the Company, including the availability of capital, timing and ability of the Company to complete certain clinical studies, and other efforts required to advance the development of its targets.
Recently issued accounting pronouncement	Recently issued accounting pronouncement In February 2016, the FASB issued ASU No. 2016-02, Leases definition of a lease. The new standard includes a short-term lease exception for leases with a term of 12 months or less, as part of which a lessee can make an accounting policy election not to recognize lease assets and lease liabilities. Lessees will continue to differentiate between finance leases (previously referred to as capital leases) and operating leases using classification criteria that are substantially similar to the previous guidance. The new standard will be effective for the Company for annual reporting periods beginning after December 15, 2021 and interim periods within fiscal years beginning after December 15, 2022, and early adoption is permitted. The Company anticipates that the adoption of this standard will have an impact on its balance sheet due to the recognition of right-of-use assets and lease liabilities; however, the Company is currently evaluating the impact that the adoption of ASU 2016-02 may have on its condensed financial statements.

Supplemental financial inform_2

Supplemental financial information (Tables)	6 Months Ended
	Jun. 30, 2021
Supplemental financial information
Schedule of cash, cash equivalents and restricted cash	. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets that sum to the total of the same such amounts shown in the condensed statements of cash flows (in thousands). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ 2021 2020 Cash and cash equivalents ​ $ 129,226 ​ $ 141,028 ​ Short-term and long-term restricted cash ​ 271 ​ 271 ​ Total cash, cash equivalents, and restricted cash shown in the statements of cash flows ​ $ 129,497 ​ $ 141,299 ​
Schedule of prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ 2021 2020 Prepaid clinical $ 1,669 ​ $ 6,052 Prepaid insurance ​ ​ 88 ​ ​ 1,177 ​ Prepaid manufacturing costs ​ ​ 2,308 ​ ​ 613 ​ Other prepaid expenses and current assets 307 ​ 298 Total prepaid expenses and other current assets $ 4,372 ​ $ 8,140
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ 2021 2020 Employee-related expenses ​ $ 1,135 ​ $ 2,039 ​ Development costs and sponsored research ​ 728 ​ 897 ​ Clinical trials ​ 656 ​ 195 ​ Other ​ 429 ​ 243 ​ Total accrued expenses and other current liabilities ​ $ 2,948 ​ $ 3,374 ​

Fair value measurements (Tables

Fair value measurements (Tables)	6 Months Ended
	Jun. 30, 2021
Fair value measurements
Schedule of assets measured at fair value	Assets measured at fair value as of June 30, 2021 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ ​ ​ 2021 Level 1 Level 2 Level 3 Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds, included in cash and cash equivalents ​ $ 128,693 ​ $ 128,693 ​ $ — ​ $ — Money market funds, included in restricted cash ​ ​ 179 ​ ​ 179 ​ — ​ — Money market funds, included in other assets ​ 92 ​ 92 ​ — ​ — ​ ​ $ 128,964 ​ $ 128,964 ​ $ — ​ $ — ​ Assets measured at fair value as of December 31, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ ​ ​ ​ 2020 Level 1 Level 2 Level 3 Assets ​ ​ ​ ​ Money market funds, included in cash and cash equivalents ​ $ 140,283 ​ $ 140,283 ​ $ — ​ $ — Money market funds, included in restricted cash ​ ​ 179 ​ ​ 179 ​ — ​ — Money market funds, included in other assets ​ ​ 92 ​ 92 ​ — ​ — ​ ​ $ 140,554 ​ $ 140,554 ​ $ — ​ $ —

Property and equipment, net (Ta

Property and equipment, net (Tables)	6 Months Ended
	Jun. 30, 2021
Property and equipment, net
Schedule of property and equipment, net	Property and equipment are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ ​ ​ June 30, ​ December 31, ​ ​ ​ 2021 2020 Computer software and equipment ​ $ — $ 15 ​ Office equipment and furniture ​ 152 ​ 176 ​ Laboratory equipment ​ 401 ​ 1,801 ​ Leasehold improvements ​ 979 ​ 1,062 ​ Less accumulated depreciation ​ (1,233) ​ (2,144) ​ Property and equipment, net ​ $ 299 ​ $ 910 ​

Stock incentive plans (Tables)

Stock incentive plans (Tables)	6 Months Ended
	Jun. 30, 2021
Stock incentive plans
Allocation of stock-based compensation expenses	Non-cash stock-based compensation expense recognized in the accompanying condensed statements of operations relating to stock options, restricted stock awards, and restricted stock units for the three and six months ended June 30, 2021 and 2020 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2021 2020 2021 2020 Research and development ​ $ 676 ​ $ 559 ​ $ 1,413 ​ $ 1,365 ​ General and administrative ​ 1,802 ​ 1,944 ​ 3,720 ​ 2,960 ​ Total stock‑based compensation expense ​ $ 2,478 ​ $ 2,503 ​ $ 5,133 ​ $ 4,325 ​
Schedule of restricted stock unit activity	The table below summarizes activity related to restricted stock units (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ‑ ​ ​ ​ ​ average ​ ​ ​ ​ grant date ​ ​ ​ ​ fair value ​ ​ Shares ​ per share Unvested as of December 31, 2020 1,091 ​ $ 3.63 Issued ​ ​ $ ​ Vested (1,089) ​ ​ 3.63 Forfeited and canceled (2) ​ 3.63 Unvested as of June 30, 2021 — ​ $ —
Summary of stock option activity	The table below summarizes activity related to stock options (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ‑ ​ ​ ​ ​ ​ ​ Weighted ‑ ​ average ​ ​ ​ ​ ​ ​ ​ average ​ remaining ​ Aggregate ​ ​ ​ ​ exercise ​ contractual ​ intrinsic Options ​ Shares ​ price ​ term ​ value Outstanding, December 31, 2020 6,684 ​ $ 6.88 7.96 ​ $ 1,582 Granted 3,080 ​ 3.50 ​ Exercised ​ (87) ​ ​ 1.53 ​ ​ ​ ​ ​ Forfeited and canceled (189) ​ 6.67 ​ Outstanding, June 30, 2021 ​ 9,488 ​ $ 5.83 ​ 8.26 ​ $ 405 Vested and expected to vest at June 30, 2021 ​ 9,488 ​ $ 5.83 ​ 8.26 ​ $ 405 Exercisable at June 30, 2021 4,139 ​ $ 7.12 7.15 ​ $ 246

Net loss per share (Tables)

Net loss per share (Tables)	6 Months Ended
	Jun. 30, 2021
Net loss per share
Schedule of basic and diluted net loss per share attributable to common stockholders calculation	Basic and diluted net loss per share attributable to common stockholders was calculated as follows for the three and six months ended June 30, 2021 and 2020 (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2021 2020 2021 2020 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to common stockholders ​ $ (19,819) ​ $ (12,517) ​ $ (34,045) ​ $ (27,227) ​ Denominator: ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding—basic and diluted ​ 67,381 ​ 45,680 ​ 66,716 ​ 44,757 ​ Net loss per share attributable to common stockholders—basic and diluted ​ $ (0.29) ​ $ (0.27) ​ $ (0.51) ​ $ (0.61) ​
Schedule of anti-dilutive securities excluded from computation of diluted net loss per share	The following common stock equivalents outstanding as of June 30, 2021 and 2020, were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands): ​ ​ ​ ​ ​ ​ ​ As of ​ ​ June 30, ​ 2021 2020 Stock options issued and outstanding 9,488 6,680 Unvested restricted stock ​ — ​ 1,131 Total 9,488 7,811

Organization (Details)

Organization (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 26, 2020	Jan. 14, 2020	Jul. 01, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2020
Organization
Number of common stock shares newly issued	16,100,000	11,691,666
Public offering price of the shares sold	$ 3	$ 3
Proceeds from public offering, net of underwriters' discounts	$ 45,100	$ 33,300		$ 14,615	$ 4,668
Cash and cash equivalents				$ 129,226		$ 129,226	$ 141,028
Expected period of sufficient funds for planned operations				12 months
ATM Offering
Organization
Number of common stock shares newly issued				3,629,458		5,120,940
Public offering price of the shares sold				$ 3.99		$ 3.99
Proceeds from public offering, net of underwriters' discounts				$ 14,500		$ 20,400
Threshold shares agreed to be sold			$ 50,000
Sales commission percentage			3.00%

Supplemental financial inform_3

Supplemental financial information - Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Supplemental financial information
Cash and cash equivalents	$ 129,226	$ 141,028
Short-term and long-term restricted cash	271	271
Total cash, cash equivalents, and restricted cash shown in the statements of cash flows	$ 129,497	$ 141,299	$ 116,223	$ 99,194

Supplemental financial inform_4

Supplemental financial information - Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Supplemental financial information
Prepaid clinical	$ 1,669	$ 6,052
Prepaid insurance	88	1,177
Prepaid manufacturing costs	2,308	613
Other prepaid expenses and current assets	307	298
Total prepaid expenses and other current assets	$ 4,372	$ 8,140

Supplemental financial inform_5

Supplemental financial information - Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Supplemental financial information
Employee-related expenses	$ 1,135	$ 2,039
Development costs and sponsored research	728	897
Clinical trials	656	195
Other	429	243
Total accrued expenses and other current liabilities	$ 2,948	$ 3,374

Research collaboration agreem_2

Research collaboration agreement with Allergan (Details) $ in Thousands	Jul. 24, 2015USD ($)Option	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)
Research collaboration agreement with Allergan
Research and development		$ 14,796	$ 8,365	$ 25,110	$ 19,420
RCA
Research collaboration agreement with Allergan
Agreement term	180 days
Number of options to acquire molecules | Option	3
Payment of option exercise fee	$ 1,000
Milestone payment				1,000
Capitalized contract costs		0		0
Research and development		$ 0	$ 1,000	$ 0	$ 2,600
Development activities reimbursement percentage		50.00%	50.00%	50.00%	50.00%
Development activities expenses reimbursed		$ 0	$ 500	$ 0	$ 1,300

Fair value measurements (Detail

Fair value measurements (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair value measurements
Assets measured at fair value	$ 128,964	$ 140,554
Money market funds, included in cash and cash equivalents
Fair value measurements
Money market funds	128,693	140,283
Money market funds, included in restricted cash
Fair value measurements
Money market funds	179	179
Money market funds, included in other assets
Fair value measurements
Money market funds	92	92
Level 1
Fair value measurements
Assets measured at fair value	128,964	140,554
Level 1 | Money market funds, included in cash and cash equivalents
Fair value measurements
Money market funds	128,693	140,283
Level 1 | Money market funds, included in restricted cash
Fair value measurements
Money market funds	179	179
Level 1 | Money market funds, included in other assets
Fair value measurements
Money market funds	$ 92	$ 92

Property and equipment, net (De

Property and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Property and equipment
Less accumulated depreciation	$ (1,233)		$ (1,233)		$ (2,144)
Property and equipment, net	299		299		910
Depreciation	100	$ 100	500	$ 300
Computer software and equipment
Property and equipment
Property and equipment, gross					15
Office equipment and furniture
Property and equipment
Property and equipment, gross	152		152		176
Laboratory equipment
Property and equipment
Property and equipment, gross	401		401		1,801
Leasehold improvements
Property and equipment
Property and equipment, gross	$ 979		$ 979		$ 1,062

Stock incentive plans (Details)

Stock incentive plans (Details) - 2018 Plan - shares	Jan. 01, 2021	Jun. 30, 2021
Stock incentive plans
Percentage of increase in number of shares outstanding		4.00%
Common stock added to plan	2,530,267
Awards available for future grant		1,885,199

Stock incentive plans - Stock-b

Stock incentive plans - Stock-based compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,478	$ 2,503	$ 5,133	$ 4,325
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	676	559	1,413	1,365
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,802	$ 1,944	$ 3,720	$ 2,960

Stock incentive plans - Activit

Stock incentive plans - Activity related to stock options (Details) - Stock options - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Shares
Outstanding, at the beginning of the period	6,684
Granted	3,080	2,400
Exercised	(87)
Forfeited and canceled	(189)
Outstanding, at the end of the period	9,488		6,684
Vested and expected to vest	9,488
Exercisable	4,139
Weighted-average exercise price
Outstanding, at the beginning of the period	$ 6.88
Granted	3.50
Exercised	1.53
Forfeited and canceled	6.67
Outstanding, at the end of the period	5.83		$ 6.88
Vested and expected to vest	5.83
Exercisable at the end of the period	$ 7.12
Weighted-average remaining contractual term
Weighted-average remaining contractual term	8 years 3 months 3 days		7 years 11 months 15 days
Vested and expected to vest	8 years 3 months 3 days
Exercisable	7 years 1 month 24 days
Aggregate intrinsic value
Outstanding, at the beginning of the period	$ 1,582
Outstanding, at the end of the period	405		$ 1,582
Vested and expected to vest	405
Exercisable	$ 246
Weighted-average grant date fair value per share	$ 2.73	$ 2.06
Unrecognized stock-based compensation related to non-vested stock options	$ 17,400
Expenses recognized over a weighted-average period (in years)	2 years 6 months
Term of award	10 years
Vesting period	4 years

Stock incentive plans - Restric

Stock incentive plans - Restricted stock units (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2020	May 31, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted-average grant date fair value per share
Non-cash restricted stock unit award expense recognized			$ 2,478	$ 2,503	$ 5,133	$ 4,325
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	10 months	2 years
Shares
Unvested at beginning of period (in shares)					1,091,000
Issued (in shares)	205,200	1,183,400
Vested					(1,089,000)
Forfeited and canceled (in shares)					(2,000)
Weighted-average grant date fair value per share
Unvested at beginning of period (in dollars per share)					$ 3.63
Vested (in dollars per share)					3.63
Forfeited and canceled (in dollars per share)					$ 3.63
Non-cash restricted stock unit award expense recognized			200	$ 500	$ 800	$ 900
Unrecognized compensation related to unvested restricted stock units			$ 0		$ 0

Net loss per share (Details)

Net loss per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net loss attributable to common stockholders	$ (19,819)	$ (12,517)	$ (34,045)	$ (27,227)
Denominator:
Weighted-average common shares outstanding-basic and diluted	67,381	45,680	66,716	44,757
Net loss per share attributable to common stockholders-basic and diluted	$ (0.29)	$ (0.27)	$ (0.51)	$ (0.61)

Net loss per share - Anti-dilut

Net loss per share - Anti-dilutive securities (Details) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Common stock equivalents outstanding excluded from the computation of diluted net loss per share attributable to common stockholders
Outstanding anti-dilutive securities excluded from computation of diluted net loss per share	9,488	7,811
Stock options
Common stock equivalents outstanding excluded from the computation of diluted net loss per share attributable to common stockholders
Outstanding anti-dilutive securities excluded from computation of diluted net loss per share	9,488	6,680
Unvested restricted stock units
Common stock equivalents outstanding excluded from the computation of diluted net loss per share attributable to common stockholders
Outstanding anti-dilutive securities excluded from computation of diluted net loss per share		1,131

Commitments and contingencies (

Commitments and contingencies (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Commitments and contingencies
Rent expense inclusive of lease incentives	$ 0.2	$ 0.2	$ 0.4	$ 0.4