Aptinyx (APTX) 10-K 30 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Mar. 23, 2020	Jun. 28, 2019
Document and Entity Information
Entity Registrant Name	APTINYX INC.
Entity Central Index Key	0001674365
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 62
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		45,534,432
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 98,849	$ 150,637
Restricted cash	179	252
Accounts receivable	444	578
Prepaid expenses and other current assets	5,637	1,784
Total current assets	105,109	153,251
Other assets	166	673
Property and equipment, net	1,204	1,690
Total assets	106,479	155,614
Current liabilities:
Accounts payable	1,555	1,889
Accrued expenses and other current liabilities	3,341	3,996
Total current liabilities	4,896	5,885
Other long-term liabilities	272	418
Total liabilities	5,168	6,303
Commitments and contingencies (see Note 15)
Stockholders' equity:
Preferred stock, $0.01 par value, 10,000 shares authorized and no shares issued and outstanding as of December 31, 2019 and December 31, 2018
Common stock, $0.01 par value, 150,000 shares authorized as of December 31, 2019 and December 31, 2018, 33,739 and 33,341 issued and outstanding as of December 31, 2019 and December 31, 2018	337	333
Additional paid-in capital	263,922	254,516
Accumulated deficit	(162,948)	(105,538)
Total stockholders’ equity	101,311	149,311
Total liabilities and stockholders’ equity	$ 106,479	$ 155,614

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2019	Dec. 31, 2018
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	33,739	33,341
Common stock, shares outstanding	33,739	33,341

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total revenues	$ 3,669	$ 6,574
Operating expenses:
Research and development	44,330	48,788
General and administrative	18,952	12,674
Total operating expenses	63,282	61,462
Loss from operations	(59,613)	(54,888)
Other income	2,203	1,607
Net loss and comprehensive loss	$ (57,410)	$ (53,281)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (1.71)	$ (2.64)
Weighted-average number of common shares outstanding, basic and diluted (in shares)	33,556	20,199
Collaboration revenue
Revenues:
Total revenues	$ 3,669	$ 4,932
Grant revenue
Revenues:
Total revenues		$ 1,642

Statements of Convertible Prefe

Statements of Convertible Preferred Stock shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)shares
Convertible Preferred Stock Rollforward
Issuance of common stock upon IPO, net of underwriters’ discount and other offering costs of $3,012	$ 106,505
Series A-1
Convertible Preferred Stock Rollforward
Convertible preferred stock beginning balance	$ 22,650
Convertible preferred stock shares beginning balance | shares	151,773
Conversion of preferred stock upon IPO	$ (22,650)
Conversion of preferred stock upon IPO (in shares) | shares	(151,773)
Series A-2
Convertible Preferred Stock Rollforward
Convertible preferred stock beginning balance	$ 39,979
Convertible preferred stock shares beginning balance | shares	173,453
Conversion of preferred stock upon IPO	$ (39,979)
Conversion of preferred stock upon IPO (in shares) | shares	(173,453)
Series B
Convertible Preferred Stock Rollforward
Convertible preferred stock beginning balance	$ 69,757
Convertible preferred stock shares beginning balance | shares	234,955
Conversion of preferred stock upon IPO	$ (69,757)
Conversion of preferred stock upon IPO (in shares) | shares	(234,955)

Statements of Stockholders' Equ

Statements of Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Common stock	Additional paid-in capital	Accumulated deficit	Total
Stockholders' (deficit) equity beginning balance at Dec. 31, 2017	$ 53	$ 12,486	$ (52,257)	$ (39,718)
Stockholders' (deficit) equity shares beginning balance at Dec. 31, 2017	5,342
Stockholders' (Deficit) Equity Rollforward
Issuance of common stock upon vesting of restricted stock awards	$ 3	(3)
Issuance of common stock upon vesting of restricted stock awards (in shares)	293
Stock-based compensation		3,318		3,318
Conversion of preferred stock upon IPO	$ 203	132,183		132,386
Conversion of preferred stock upon IPO (in shares)	20,306
Issuance of common stock upon IPO, net of underwriters’ discount and other offering costs of $3,012	$ 74	106,431		106,505
Issuance of common stock upon IPO, net of underwriters’ discount and other offering costs of $3,012 (in shares)	7,360
Issuance of common stock upon exercise of stock options		101		101
Issuance of common stock upon exercise of stock options (in shares)	40
Net loss			(53,281)	(53,281)
Stockholders' (deficit) equity ending balance at Dec. 31, 2018	$ 333	254,516	(105,538)	$ 149,311
Stockholders' (deficit) equity shares ending balance at Dec. 31, 2018	33,341			33,341
Stockholders' (Deficit) Equity Rollforward
Issuance of common stock upon vesting of restricted stock awards	$ 2	(2)
Issuance of common stock upon vesting of restricted stock awards (in shares)	217
Stock-based compensation		9,036		$ 9,036
Issuance of common stock upon exercise of stock options	$ 2	372		374
Issuance of common stock upon exercise of stock options (in shares)	181
Net loss			(57,410)	(57,410)
Stockholders' (deficit) equity ending balance at Dec. 31, 2019	$ 337	$ 263,922	$ (162,948)	$ 101,311
Stockholders' (deficit) equity shares ending balance at Dec. 31, 2019	33,739			33,739

Statements of Stockholders' E_2

Statements of Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Statements of Stockholders' Equity (Deficit)
Stock issuance costs capitalized	$ 3,012

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (57,410)	$ (53,281)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	455	457
Loss on disposal of property and equipment	3
Stock-based compensation expense	9,036	3,318
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,166)	(260)
Accounts receivable	134	359
Accounts payable	(361)	418
Accrued expenses and other liabilities	(778)	1,541
Net cash used in operating activities	(52,087)	(47,448)
Cash flows from investing activities:
Purchases of property and equipment	(43)	(407)
Proceeds from sale of property and equipment	4
Net cash used in investing activities	(39)	(407)
Cash flows from financing activities:
Payment of deferred issuance costs associated with Series B convertible preferred stock financing		(232)
Proceeds from stock options exercised	374	101
Proceeds from initial public offering, net of underwriters' discounts		109,517
Payment of deferred offering costs	(182)	(3,012)
Net cash provided by financing activities	192	106,374
Net (decrease) increase in cash, cash equivalents and restricted cash	(51,934)	58,519
Cash, cash equivalents and restricted cash, at beginning of period	151,128	92,609
Cash, cash equivalents and restricted cash, at end of period	99,194	$ 151,128
Supplemental disclosure of non-cash investing and financing activities:
Deferred offering costs not yet paid	70
Property and equipment in accounts payable	$ 11

Organization

Organization	12 Months Ended
	Dec. 31, 2019
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 a number of brain and nervous system disorders. Liquidity and capital resources The Company has incurred losses and negative cash flows from operations since inception and had an accumulated deficit of $162.9 million as of December 31, 2019. The Company expects to incur substantial operating losses for the next several years and will need to obtain additional financing in order to complete clinical studies and launch and commercialize any product candidates for which it receives regulatory approval. There can be no assurance that such financing will be available or will be at terms acceptable to the Company. As of December 31, 2019, the Company had cash and cash equivalents of $98.8 million which, when combined with the proceeds received from the Company’s follow-on offering discussed below (see Note 16), it believes will be sufficient to fund its planned operations for a period of at least twelve months from the date of the issuance of these financial statements. Initial public offering On June 20, 2018, the Company’s registration statement on Form S - 1 (File No. 333‑225150) relating to the initial public offering (“IPO”) of its common stock became effective and on June 25, 2018, the IPO closed. Pursuant to the IPO, the Company issued and sold 7,359,998 shares of common stock at a public offering price of $16.00 per share, which included 959,999 shares sold pursuant to the exercise of the underwriters’ option to purchase additional shares. The Company received net proceeds of $106.5 million after deducting underwriting discounts and commissions and other offering costs of $3.0 million. The shares began trading on the Nasdaq Global Select Market on June 21, 2018. Upon the closing of the IPO, all of the Company’s outstanding shares of convertible preferred stock automatically converted into 20,306,497 shares of common stock at the applicable conversion ratio. On June 7, 2018, the Company effected a one-for-27.58621 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of the Company's redeemable convertible preferred stock (see Note 10). Accordingly, all share and per share amounts for all periods presented in the financial statements have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios. The Company is also authorized to issue 10 million shares of undesignated preferred stock, par value $0.01, in one or more series. As of December 31, 2019, no shares of preferred stock were issued or outstanding.

Basis of presentation

Basis of presentation	12 Months Ended
	Dec. 31, 2019
Basis of presentation
Basis of Presentation	2. Basis of presentation The accompanying financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). 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. Recently adopted accounting pronouncements In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, which amends the guidance for accounting for revenue from contracts with customers. This ASU supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition , (“ASC 605”), and creates a new topic, ASC 606, Revenue from Contracts with Customers . Through subsequent targeted amendments, the FASB issued additional ASUs that delayed the effective date of ASC 606 and clarified various aspects of the new revenue guidance, including principal versus agent considerations, identifying performance obligations, licensing, and other improvements and practical expedients. The Company adopted this new standard on January 1, 2019 using the modified retrospective transition method. The Company presents revenue from contracts with customers as collaboration revenue in the Company’s statements of operations. The Company applied this new standard to all contracts with customers that were not complete as of the adoption date and has determined that no cumulative catch-up adjustment to accumulated deficit was required. See Note 4, “ Research collaboration agreement with Allergan” for additional information regarding the Company’s single contract that falls within the scope of ASC 606. The Company considered the adoption of ASC 606 compared to what would have been recognized by the Company under the prior revenue standard, ASC 605. The adoption of ASC 606 did not have a material impact on the Company’s financial statements as of and for the year ended December 31, 2019. The Company has determined that the accounting for the Company’s various grant agreements is outside the scope of ASC 606, as the government agencies granting the Company funds are not receiving reciprocal value for their contributions. There are currently no grants outstanding in 2019. Since the accounting for government grants falls outside the scope of ASC 606, the Company has reclassified the grant income earned in 2018 separate and apart from revenue earned from contracts with customers in the Company’s statements of operations to conform to the current year presentation. In June 2018, the FASB issued ASU 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting . This ASU expands the scope of Topic 718, Compensation—Stock Compensation to include share-based payments issued to nonemployees for goods or services. Under the new guidance, the existing employee guidance will apply to nonemployee share based transactions (as long as the transaction is not effectively a form of financing), with the exception of specific guidance related to the attribution of compensation cost. The cost of nonemployee awards will continue to be recorded as if the grantor had paid cash for the goods or services. The new accounting guidance will be effective for the Company on January 1, 2020. The Company has early adopted this new standard on January 1, 2019. The adoption did not have a material impact on the Company’s financial statements. Recently issued accounting pronouncements In February 2016, the FASB issued ASU No. 2016‑02, Leases (“ASC 842”), which requires a lessee to recognize assets and liabilities on the balance sheet for operating leases and changes many key definitions, including the 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 in fiscal years beginning after December 15, 2020, 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 ASC 842 will have on its financial statements.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2019
Summary of significant accounting policies
Summary of significant accounting policies	3. Summary of significant accounting policies Use of estimates The 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: future clinical study results, the scope, 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. The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company. The Company is dependent upon third‑party manufacturers to supply product for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and final drug product related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and final drug product. Revenue recognition Revenue is recognized in accordance with revenue recognition accounting guidance, which utilizes five steps to determine whether revenue can be recognized and to what extent: (i) identify the contract with a customer; (ii) identify the performance obligation(s); (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) determine the recognition period. The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, Revenue from Contracts with Customers, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Significant judgments exercised by management include the identification of performance obligations, and whether such promised goods or services are considered distinct. The Company evaluates promised goods or services on a contract by contract basis to determine whether each promise represents a good or service that is distinct or has the same pattern of transfer as other promises. A promised good or service is considered distinct if the customer can benefit from the good or service independently of other goods/services either in the contract or that can be obtained elsewhere, without regard to contract exclusivity, and the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contact. If the good or service is not considered distinct, the Company combines such promises and accounts for them as a single combined performance obligation. Accounts receivable Accounts receivable that management has the intent and ability to collect are reported in the balance sheets at outstanding amounts, less an allowance for doubtful accounts. During the years ended December 31, 2019 and 2018, one research collaborator, Allergan plc (“Allergan”) represented 100% and 75%, respectively, of the Company’s revenues (see Note 4). The associated accounts receivable were approximately $0.4 million and $0.6 million at December 31, 2019 and 2018, respectively. The Company writes off uncollectible receivables based on specific identification when the likelihood of collection is remote. No allowance was deemed necessary at December 31, 2019 and 2018. 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 statements of cash flows (amounts in thousands). As of December 31, Cash and cash equivalents $ 98,849 $ 150,637 Short-term and long-term restricted cash 345 491 Total cash, cash equivalents, and restricted cash shown in the statements of cash flows $ 99,194 $ 151,128 Amounts included in restricted cash represent those amounts required to be held as a security deposit in the form of letters of credit for the Company’s leased office facility and cash collateral held by credit card. Concentrations of credit risk The Company, at times, maintains cash and cash equivalents in accounts with a financial institution in excess of the amount insured by the Federal Deposit Insurance Corporation. The Company monitors the financial stability of this institution regularly and management does not believe there is significant credit risk associated with deposits in excess of federally insured amounts. Fair value of financial instruments ASC 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three‑tier fair value hierarchy that distinguishes between the following: · 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. There were no Level 3 assets or liabilities as of December 31, 2019 or 2018. 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. Property and equipment Property and equipment are stated at cost. Maintenance and repairs are charged to expense as incurred. Additions, improvements and replacements are capitalized. Depreciation of property and equipment is provided for by the straight‑line method over the estimated useful lives of the related assets. The estimated useful lives of property and equipment are as follows: Description Estimated useful life Computer software and equipment 3 years Office equipment and furniture 5 years Laboratory equipment 5 years Leasehold improvements Lesser of the estimated useful life or term of the lease Construction-in-progress reflects property and equipment yet to be placed in service. Impairment of long‑lived assets Long‑lived assets consist of property and equipment. Long‑lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. If the sum of the estimated future undiscounted cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset group, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset group. The Company has not recorded any impairment losses on long‑lived assets for the years ended December 31, 2019 and 2018. Research and development Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries and benefits, facilities costs, overhead costs, depreciation, contract services and other related costs. Research and development costs are expensed to operations as the related obligation is incurred. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and are reflected on the balance sheet as prepaid or accrued expenses. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Convertible preferred stock The Company has applied the guidance in ASC 480‑10‑S99‑3A, SEC Staff Announcement: Classification and Measurement of Redeemable Securities and has therefore classified the Series A‑1, Series A‑2 and Series B convertible preferred stock (Note 10) as mezzanine equity. The convertible preferred stock was recorded outside of stockholders’ deficit because, in the event of certain deemed liquidation events considered not solely within the Company’s control, such as a merger, acquisition and sale of all or substantially all of the Company’s assets, the convertible preferred stock would have become redeemable at the option of the holders. In the event of a change of control of the Company, proceeds received from the sale of such shares will be distributed in accordance with the liquidation preferences set forth in the Company’s Amended and Restated Certificate of Incorporation. The Company determined not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because of the uncertainty of whether or when such an event would occur. As described in Note 1, all previously outstanding convertible preferred stock was converted to common stock upon the completion of the Company’s IPO in June 2018. Stock‑based compensation The Company has stock‑based compensation plans that cover the Company’s directors and employees and are more fully described in Note 11. Stock‑based compensation cost is estimated at the grant date based on the fair value of the award, and the cost is recognized as expense ratably over the vesting period. Income taxes The Company accounts for income taxes under the liability method in accordance with FASB ASC 740, Income Taxes. Under this method, deferred income tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. A valuation allowance is established if it is more likely than not that all, or some portion, of deferred income tax assets will not be realized. The Company has recorded a full valuation allowance to reduce its net deferred income tax assets to zero. In the event the Company were to determine that it would be able to realize some or all its deferred income tax assets in the future, an adjustment to the deferred income tax asset valuation allowance would increase income in the period such determination was made. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. Any recognized income tax positions would be measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement would be reflected in the period in which the change in judgment occurs. At December 31, 2019 and 2018, the Company had no liability for income tax associated with uncertain tax positions. The Company would recognize any corresponding interest and penalties associated with its income tax positions in income tax expense. There was no income tax interest or penalties incurred in 2019 or 2018. Segment data The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is on advancing therapies to treat disorders of the brain and nervous system. All tangible assets are held in the United States and all revenue is generated in the United States. Comprehensive loss Comprehensive loss is equal to net loss as presented in the accompanying statements of operations. Net loss per share Basic net loss per share is calculated by dividing the net loss by the weighted‑average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the Company has reported net losses for each period presented.

Research collaboration agreemen

Research collaboration agreement with Allergan	12 Months Ended
	Dec. 31, 2019
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”), focused on the research and discovery of small molecules that modulate NMDArs. The collaboration is 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 will terminate upon the earlier of a predetermined anniversary of the RCA or on the date on which Allergan exercises three options to acquire molecules from a pool of eligible compounds. Under the terms of the agreement, Allergan will pay the Company $1.0 million for each option exercised by Allergan. On May 16, 2018, Allergan exercised its option to acquire exclusive rights to develop and commercialize AGN-241751 within a predefined set of indications. 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 provides research and development services that are 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 participates in a joint steering committee, which allows 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 is 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 on 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 any future options exercised are not considered a performance obligation until the time of option exercise. Transaction price The RCA includes both fixed and variable consideration. Fixed payments, such as contractually defined fees per full-time employee (“FTE”), are included in the transaction price at contract inception, while variable consideration, such as reimbursement for Research and Development Services, are estimated and then evaluated for constraints upon inception of the contract and evaluated on a quarterly basis thereafter. Research and Development Services are updated for actual invoices. There were no capitalized costs associated with obtaining the contract. The Company concluded that it will use an input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. The Company uses 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 will 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 years ended December 31, 2019 and 2018, the Company recorded expenses of $7.3 million and $7.9 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 $3.7 million and $3.9 million during the years ended December 31, 2019 and 2018, respectively. Such reimbursements were reported within collaboration revenue in the statements of operations. On May 16, 2018, Allergan exercised its option to acquire exclusive rights to develop and commercialize AGN-241751 within a specific set of indications. For the year ended December 31, 2018, 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.

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2019
Fair value measurements
Fair value measurements	5. Fair value measurements Assets measured at fair value as of December 31, 2019 are as follows (in thousands): December 31, Level 1 Level 2 Level 3 Assets Money market funds, included in cash and cash equivalents $ 97,998 $ 97,998 $ — $ — Money market funds, included in restricted cash 179 179 — — Money market funds, included in other assets 166 166 — — $ 98,343 $ 98,343 $ — $ — Assets measured at fair value as of December 31, 2018 are as follows (in thousands): December 31, Level 1 Level 2 Level 3 Assets Money market funds, included in cash and cash equivalents $ 150,151 $ 150,151 $ — $ — Money market funds, included in restricted cash 252 252 — — Money market funds, included in other assets 239 239 — — $ 150,642 $ 150,642 $ — $ —

Prepaid expenses and other curr

Prepaid expenses and other current assets	12 Months Ended
	Dec. 31, 2019
Prepaid expenses and other current assets
Prepaid expenses and other current assets	6. Prepaid expenses and other current assets Prepaid expenses and other current assets consist of the following (in thousands): As of December 31, Prepaid clinical $ 3,719 $ 728 Prepaid insurance 994 673 Prepaid manufacturing costs 558 — Other prepaid expenses and current assets 366 383 Total prepaid expenses and other current assets $ 5,637 $ 1,784

Property and equipment

Property and equipment	12 Months Ended
	Dec. 31, 2019
Property and equipment
Property and equipment	7 . Property and equipment Property and equipment are as follows (in thousands): As of December 31, Computer software and equipment $ 15 $ 15 Office equipment and furniture 176 176 Laboratory equipment 1,597 1,571 Leasehold improvements 1,051 1,051 Construction-in-progress 11 — Less accumulated depreciation (1,646) (1,123) Property and equipment, net $ 1,204 $ 1,690 Depreciation expense was $0.5 million for each of the years ended December 31, 2019 and 2018.

Accrued expenses and other curr

Accrued expenses and other current liabilities	12 Months Ended
	Dec. 31, 2019
Accrued expenses and other current liabilities
Accrued expenses and other current liabilities	8. Accrued expenses and other current liabilities Accrued expenses and other current liabilities consist of the following (in thousands): As of December 31, Employee-related expenses $ 1,925 $ 2,043 Development costs and sponsored research 652 915 Clinical trials 410 607 Other 354 431 Total accrued expenses and other current liabilities $ 3,341 $ 3,996

Operating leases

Operating leases	12 Months Ended
	Dec. 31, 2019
Operating leases
Operating leases	9. Operating 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 balance sheets within both accrued expenses and other current liabilities and other long-term liabilities. On October 13, 2016, the Company entered into a lease agreement with the landlord for office space totaling approximately 16,500 square feet. The term of this lease commenced on April 1, 2017 and continues through August 31, 2022. The Company has an option to renew the lease for one renewal term of 5 years. The lease provided the Company with a tenant improvement allowance of $0.4 million. The Company recorded the tenant improvement allowance incurred as a deferred lease incentive and is amortizing the deferred lease incentive through a reduction of rent expense ratably over the lease term. On July 18, 2018, the Company entered into a sublease agreement for additional office space adjacent to the Company’s existing headquarters in Evanston, Illinois, totaling approximately 6,172 square feet. The term of the lease commenced on July 18, 2018 and continues through September 30, 2022. On January 31, 2019, the sublease agreement was terminated, and the Company entered into an amended lease agreement with the landlord for the same additional office space. The terms commence on February 1, 2019 and continue through August 31, 2022. Total rent expense, inclusive of lease incentives, under the operating lease agreements amounted to $0.9 million and $0.7 million for the years ended December 31, 2019 and 2018, respectively. Aggregate future minimum annual rental commitments under these non‑cancelable lease agreements are as follows at December 31, 2019 (in thousands): Year ending December 31, 2020 $ 864 2021 876 2022 590 2023 — 2024 — Thereafter — $ 2,330

Convertible preferred stock and

Convertible preferred stock and stockholders’ equity	12 Months Ended
	Dec. 31, 2019
Convertible preferred stock and stockholders’ equity
Convertible preferred stock and stockholders’ equity	10. Convertible preferred stock and stockholders’ equity As described in Note 1, all previously outstanding convertible preferred stock was converted to common stock upon the completion of the Company’s IPO in June 2018. Series A preferred stock On May 4, 2016, the Company entered into a purchase agreement (the “Series A Purchase Agreement”) for a private placement of up to 151,772,701 shares of Series A‑1 Convertible Preferred Stock (the “Series A‑1 Preferred Stock”) and 173,453,018 shares of Series A‑2 Convertible Preferred Stock (the “Series A‑2 Preferred Stock” and together with the Series A‑1 Preferred Stock, the “Series A Preferred Stock”) under the Series A Purchase Agreement. Of the 325,225,719 authorized shares of Series A Preferred Stock, 151,772,701 shares were designated Series A‑1 Preferred Stock at $0.16472 per share and 173,453,018 shares were designated Series A‑2 Preferred Stock at $0.23061 per share. The Series A Purchase Agreement obligated the investors to purchase, at the election of the Company’s board of directors (the “Board of Directors”), the Series A‑2 Preferred Stock at $0.23061 per share upon achieving certain clinical milestones. The determination as to whether the milestone event was met was subject to the certification by (i) the Board of Directors and (ii) the holders of at least a majority of the then‑outstanding Series A Preferred Stock. The Series A Purchase Agreement also obligated the Company to sell to each investor that elects to purchase such investor’s portion of Series A‑2 Preferred Stock at any time such number of shares of Series A‑2 Preferred Stock pro rata in accordance with the number of Series A‑1 Preferred Stock purchased at the initial closing (the “Tranche Rights”). In January 2017, the Company achieved its clinical milestone obligating the Company to sell its Series A‑2 Preferred Stock at $0.23061 per share. Series B preferred stock On December 11, 2017, the Company entered into a purchase agreement (the “Series B Purchase Agreement”) for a private placement of 234,954,520 shares of Series B Convertible Preferred Stock (the “Series B Preferred Stock”) in exchange for $69.8 million, net of issuance costs. All 234,954,520 authorized shares of Series B Preferred Stock were designated at $0.29793 per share. Dividends The holders of the Series A and Series B Preferred Stock are not entitled to receive dividends unless declared by the Board of Directors of the Company in accordance with the Company’s certificate of incorporation, as amended from time to time. No dividends have been declared since inception. Liquidation preference Upon a liquidation of the Company, the assets of the Company or proceeds available for distribution to the Company’s stockholders shall be paid as follows: (a) first, for each share of Series B Preferred Stock the greater of (i) one times the original purchase price plus declared and unpaid dividends on such share, or (ii) such amount as would have been payable had all shares of Series B Preferred Stock been converted to common stock immediately prior to such liquidation; and (b) then, for each share of Series A Preferred Stock the greater of (i) one times the original purchase price plus declared and unpaid dividends on such share, or (ii) such amount as would have been payable had all shares of (A) Series A‑1 Preferred Stock been converted to common stock, in the case of Series A‑1 Preferred Stock and (B) Series A‑2 Preferred Stock been converted to common stock, in the case of Series A‑2 Preferred Stock immediately prior to such liquidation. The balance of any proceeds shall be distributed pro rata to holders of common stock. If upon liquidation, the assets of the Company or proceeds available for distribution to its stockholders are insufficient to pay the holders of the Series B Preferred Stock as to their respective liquidation preferences the full amount entitled, the holders of the Series B Preferred Stock shall share ratably any distribution of the assets or proceeds available for distribution. If upon liquidation, the assets of the Company or proceeds available for distribution to its stockholders, after payment in full of the liquidation preferences to holders of the Series B Preferred Stock, are insufficient to pay the holders of the Series A Preferred Stock as to their respective liquidation preferences the full amount entitled, the holders of the Series A Preferred Stock shall share ratably any distribution of the remaining assets or proceeds available for distribution. Conversion update Shares of preferred stock are convertible into such number of fully paid and non‑assessable shares of common stock as determined by dividing the original issuance price by the conversion price at the time in effect, subject to adjustment. The original conversion price is $0.16472 for Series A‑1 Preferred Stock, $0.23061 for Series A‑2 Preferred Stock, and $0.29793 for Series B Preferred Stock, in each case, subject to adjustments to reflect the issuance of common stock, options, warrants, or other rights to subscribe for or to purchase common stock for a consideration per share, less than the conversion price then in effect and subsequent stock dividends, stock splits, combinations, or recapitalizations. Conversion is at the option of the respective holders of Series A and Series B Preferred Stock, although conversion is automatic upon the earlier of (a) the consummation of an underwritten public offering resulting in gross proceeds to the Company of at least $70 million and a share price of at least $0.446895 per share (subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization), or (b) the date and time, or the occurrence of an event, specified by the vote or written consent of the holders of at least majority of the then outstanding shares of Series A and Series B Preferred Stock, respectively; provided, that the outstanding shares of Series B Preferred Stock will not convert into shares of common stock pursuant to clause (b) without the approval of at least a majority of the then‑outstanding Series B Preferred Stock, including one or more holders of Series B Preferred Stock that (i) individually, or together with such holders’ affiliates, do not hold any Series A Preferred Stock and (ii) individually or collectively are the record holders of at least 30,208,439 shares of Series B Preferred Stock, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to the Series B Preferred Stock. Voting rights Holders of the Series A and Series B Preferred Stock are entitled to vote as a single class with the holders of common stock and shall have one vote for each equivalent common share into which the preferred stock is convertible. The holders of Series B Preferred Stock are entitled to elect one director to the Board of Directors; the holders of Series A Preferred Stock are entitled to elect four directors to the Board of Directors; and the holders of Preferred Stock and the holders of common stock on an as‑converted to common stock basis, are entitled to elect the remaining directors. Common stock As of December 31, 2019 and 2018, the Company had reserved common stock for issuance as follows (in thousands): As of December 31, Stock options issued and outstanding 4,798 3,959 Unvested restricted stock 1,032 195 5,830 4,154

Stock incentive plan

Stock incentive plan	12 Months Ended
	Dec. 31, 2019
Stock incentive plan
Stock incentive plan	11. Stock incentive plan In October 2015, the Company established a stock option plan (“2015 Plan”) to provide for the issuance of shares of common stock pursuant to stock options, stock appreciation rights, stock purchase rights, restricted stock agreements and long‑term performance awards granted to key employees, directors and consultants of the Company. 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 number of shares available for grant under the Company’s 2018 Plan as of December 31, 2019 was 3079,544, which includes 505,046 shares of the Company’s common stock reserved under the Company’s 2015 Plan that became available for issuance upon the effectiveness of the 2018 Plan. No future issuance will be made under the 2015 Plan. The number of shares available for grant under the Company’s stock option plan were as follows (in thousands): Available for grant as of January 1, 2018 2,419 Plan amendment 3,899 Grants (2,515) Forfeitures and cancellations 14 Available for grant as of December 31, 2018 3,817 Plan amendment 1,341 Grants (2,955) Forfeitures and cancellations 878 Available for grant as of December 31, 2019 3,081 Stock‑based compensation expense Non‑cash stock‑based compensation expense recognized in the accompanying statements of operations relating to both stock options and restricted stock awards for the years ended December 31, 2019 and 2018 are as follows (in thousands): Year ended December 31, Research and development $ 2,442 $ 866 General and administrative 6,594 2,452 Total stock‑based compensation expense $ 9,036 $ 3,318 Restricted stock awards In 2015, the Company granted 1.5 million restricted stock awards with a weighted‑average grant date fair value per share of $1.10. The restricted stock awards generally vest over four years, or a change in the control of the Company, subject to continued employment with the Company. In the event of a change in control, the unvested restricted stock awards will be accelerated and fully vested immediately prior to the change in control. There are no performance‑based features or market conditions in the Company’s outstanding restricted stock awards. The fair value of restricted stock awards is determined based on the number of restricted stock awards granted and the fair value of the Company’s stock on the date of grant. Non-cash restricted stock award expense recognized in the accompanying statements of operations was $0.2 million and $0.3 million for the years ended December 31, 2019 and 2018, respectively. The total fair value of shares that vested in 2019 was $0.2 million. As of December 31, 2018, there were approximately 195,000 shares of unvested restricted stock outstanding which all subsequently vested in 2019 Restricted stock units In May 2019, the Company issued an aggregate of 1,183,400 shares of restricted stock units to employees. The restricted stock units vest in 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. There are 21,764 shares of common stock underlying restricted stock outstanding as of December 31, 2019. 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, 2018 - $ - Issued 1,183 $ 3.63 Vested (26) 3.63 Forfeited and canceled (125) 3.63 Unvested as of December 31, 2019 1,032 $ 3.63 Non-cash restricted stock unit award expense recognized in the accompanying statements of operations was $1.3 million for the year ended December 31, 2019. At December 31, 2019, there was $2.6 million of unrecognized compensation cost that will be recognized as expense over a weighted-average period of 1.38 years. Stock options During the years ended December 31, 2019 and 2018, the Company granted 1.8 million and 2.5 million stock options, respectively. The options have a ten‑year life and generally vest over a period of four years, subject to continuous employment. The weighted‑average grant date fair value per share of each option granted during the years ended December 31, 2019 and 2018 was $7.98 and $7.03, respectively. As of December 31, 2019, there was $17.5 million of unrecognized compensation cost related to non‑vested stock options which is expected to be recognized over a weighted‑average period of 2.68 years. The fair value of each option award is estimated on the date of grant using a Black‑Scholes option pricing valuation model that uses various assumptions regarding the: (1) expected volatility, (2) expected life of the option, (3) expected dividend yield, and (4) risk‑free interest rate. The Company uses the historical volatility of the share values of publicly traded companies within the biotech industry as a surrogate for the expected volatility of the Company’s common stock. A zero-dividend yield is also assumed in the stock option fair value computations. The expected life of the options represents the period of time that the options granted are expected to be outstanding and has been calculated utilizing the “simplified method” for awards that qualify as “plain vanilla” options. The risk‑free rate is based on the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The specific assumptions used to determine the fair value of the stock options granted during the years ended December 31, 2019 and 2018 were as follows: Year ended December 31, Expected volatility 71%-75% Expected dividends None None Expected option life 5.00 - 6.08 Years 6.08 Years Risk-free rate 1.38 – 2.72% 2.81 – 3.06% 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, January 1, 2018 1,498 $ 2.48 8.93 $ 4,146 Granted 2,515 10.40 Exercised (40) 2.57 Forfeited and canceled (14) 4.79 Outstanding, December 31, 2018 3,959 $ 7.46 8.79 $ 35,984 Granted 1,772 12.19 Exercised (181) 2.07 Forfeited and canceled (752) 11.70 Outstanding, December 31, 2019 4,798 $ 8.75 8.29 $ 1,159 Vested and expected to vest at December 31, 2019 4,798 $ 8.75 8.29 $ 1,159 Exercisable at December 31, 2019 2,139 $ 5.64 7.87 $ 928 Employee stock purchase plan On June 5, 2018, the Company's stockholders approved the 2018 Employee Stock Purchase Plan (the "ESPP"), which became effective upon the completion of the Company's initial public offering. A total of 314,697 shares of common stock were reserved for issuance under this plan. In addition, the number of shares of common stock that may be issued under the ESPP automatically increase on January 1 of each year through January 1, 2028, by the lesser of (i) 1% of the number of shares of the Company's common stock outstanding on the immediately preceding December 31 and (ii) such lesser number of shares as determined by the administrator of the Company's ESPP.

Net loss per share

Net loss per share	12 Months Ended
	Dec. 31, 2019
Net loss per share
Net loss per share	12. Net loss per share Basic and diluted net loss per share attributable to common stockholders was calculated as follows for the years ended December 31, 2019 and 2018 (in thousands, except per share data): Year ended December 31, Numerator: Net loss attributable to common stockholders $ (57,410) $ (53,281) Denominator: Weighted-average common shares outstanding—basic and diluted 33,556 20,199 Net loss per share attributable to common stockholders—basic and diluted $ (1.71) $ (2.64) The following common stock equivalents outstanding as of December 31, 2019 and 2018, 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 December 31, Stock options issued and outstanding 4,798 3,959 Unvested restricted stock 1,032 195 5,830 4,154

Employee benefit plan

Employee benefit plan	12 Months Ended
	Dec. 31, 2019
Employee benefit plan
Employee benefit plan	13. Employee benefit plan Effective December 31, 2015, the Company established a defined contribution 401(k) plan (the “401(k) Plan”) for the benefit of its employees. All of the employees of the Company are eligible to participate in the 401(k) Plan which permits employees to make voluntary contributions up to the dollar limit allowed under the Internal Revenue Code. The 401(k) Plan also provides for matching contributions as defined by the Company of up to a combined total of 4% of an employee’s eligible annual compensation. The Company has recorded matching contributions of $0.4 million and $0.3 million for the years ended December 31, 2019 and 2018, respectively.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2019
Income taxes
Income taxes	14. Income taxes Provision for income taxes There is no provision for income taxes because the Company has historically incurred operating losses and maintains a full valuation allowance against its net deferred tax assets. The reported amount of income tax expense for the years differs from the amount that would result from applying domestic federal statutory tax rates and pretax losses primarily because of changes in valuation allowance. Deferred tax assets and valuation allowance Deferred tax assets reflect the tax effects of net operating losses (“NOLs”) and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The most significant item of deferred tax assets is derived from the Company’s federal NOLs. At December 31, 2019, the Company had a U.S. federal NOL carryforward available to offset future taxable income of $146.4 million. This includes the $7.1 million of gross NOLs that are limited under Sec. 382. Of the $146.4 million, $49.0 million will begin to expire in 2035 and $97.4 million have an indefinite carryforward period and NOL carryforwards will be limited to 80% of taxable income in future years. As of December 31, 2019, the Company had state NOL carryforwards of $13.9 million which have a 12-year carryforward period and will begin to expire starting in 2027. A reconciliation of the U.S statutory rate to the Company’s effective tax rate is as follows: Year ended December 31, Federal rate 21.0 % 21.0 % State rate 7.5 7.5 Valuation allowance (28.6) (26.8) Other 0.1 (1.7) — % — % The significant components of the Company’s net deferred tax assets are as follows (in thousands): December 31, Deferred tax assets Net operating loss $ 41,727 $ 27,749 Stock‑based compensation 2,603 — Accrued clinical trials 176 322 Accrued compensation 509 582 Accrued expenses and other, net 383 374 Total deferred tax assets 45,398 29,027 Less valuation allowance (45,398) (28,963) Net deferred tax assets — 64 Deferred tax liabilities Stock‑based compensation and other, net — (64) Net deferred taxes $ — $ — Pursuant to Section 382 of the Internal Revenue Code, certain substantial changes in the Company’s ownership may result in a limitation on the amount of NOL carryforwards and tax credit carryforwards that may be used in future years. Utilization of the NOL and tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 (“IRC Section 382”) due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the amount of NOL and tax credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. During 2018, the Company performed a detailed analysis of their historical and current IRC Section 382 ownership changes that may limit the utilization of NOL carryforwards. Except for approximately $7.1 million of NOLs arising prior to the Company’s Series A preferred stock financing in May 2016, the entire remaining NOL carryforward is available for immediate use based on the IRC Section 382 analysis performed. There could also be additional ownership changes in the future which may result in limitations on the utilization of NOL carryforwards and credits. The Company files federal and state income tax returns and, in the normal course of business, the Company is subject to examination by these taxing authorities. As of December 31, 2019, the Company’s tax years through December 31, 2015 are subject to examination by the U.S. federal and state taxing authorities. The December 31, 2018 tax year is currently under examination by the Internal Revenue Service.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and contingencies
Commitments and contingencies	15. Commitments and contingencies From time to time, the Company is 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 December 31, 2019. 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 December 31, 2019. The Company does not anticipate recognizing any significant losses relating to these arrangements.

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2019
Subsequent events
Subsequent events	16. Subsequent events Public offering of common stock On January 14, 2020, the Company completed a follow-on public offering of its common stock pursuant to an effective registration statement on Form S-3. The Company sold an aggregate of 11,691,666 shares of common stock, which included the exercise in full of the underwriters’ option to purchase additional shares at a public offering price of $3.00 per share. Net proceeds from the offering were approximately $33.3 million after deducting underwriting discounts and commissions as well as other offering expenses. COVID-19 Outbreak In March 2020, the World Health Organization declared the novel coronavirus (COVID-19) a global pandemic. This contagious disease outbreak, which has continued to spread, has adversely affected workforces, economies, and financial markets globally, potentially leading to an economic downturn. The evolving pandemic may affect patient enrollment for the Company’s ongoing Phase 2 clinical studies as patients may avoid or may not be able to travel to clinical study site locations. Similarly, this outbreak could result in the complete or partial closure of one or more of the Company’s clinical study site locations, the CRO, and/or impact the trial monitors and other critical vendors and consultants supporting the trials. 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. Additionally, while the potential economic impact brought by, and the duration of, the COVID-19 pandemic is difficult to assess or predict, the impact of the COVID-19 pandemic on the global financial markets may reduce the Company’s ability to raise additional capital on attractive terms or at all. The Company cannot at this time predict the specific extent, duration, or full impact that the COVID-19 outbreak will have on its financial condition and operations. However, these effects could have a material impact on the Company’s business, financial condition, and results of operations.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2019
Summary of significant accounting policies
Use of estimates	Use of estimates The 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: future clinical study results, the scope, 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. The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company. The Company is dependent upon third‑party manufacturers to supply product for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and final drug product related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and final drug product.
Revenue recognition	Revenue recognition Revenue is recognized in accordance with revenue recognition accounting guidance, which utilizes five steps to determine whether revenue can be recognized and to what extent: (i) identify the contract with a customer; (ii) identify the performance obligation(s); (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) determine the recognition period. The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, Revenue from Contracts with Customers, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Significant judgments exercised by management include the identification of performance obligations, and whether such promised goods or services are considered distinct. The Company evaluates promised goods or services on a contract by contract basis to determine whether each promise represents a good or service that is distinct or has the same pattern of transfer as other promises. A promised good or service is considered distinct if the customer can benefit from the good or service independently of other goods/services either in the contract or that can be obtained elsewhere, without regard to contract exclusivity, and the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contact. If the good or service is not considered distinct, the Company combines such promises and accounts for them as a single combined performance obligation.
Accounts receivable	Accounts receivable Accounts receivable that management has the intent and ability to collect are reported in the balance sheets at outstanding amounts, less an allowance for doubtful accounts. During the years ended December 31, 2019 and 2018, one research collaborator, Allergan plc (“Allergan”) represented 100% and 75%, respectively, of the Company’s revenues (see Note 4). The associated accounts receivable were approximately $0.4 million and $0.6 million at December 31, 2019 and 2018, respectively. The Company writes off uncollectible receivables based on specific identification when the likelihood of collection is remote. No allowance was deemed necessary at December 31, 2019 and 2018.
Cash, cash equivalents and restricted cash	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 statements of cash flows (amounts in thousands). As of December 31, Cash and cash equivalents $ 98,849 $ 150,637 Short-term and long-term restricted cash 345 491 Total cash, cash equivalents, and restricted cash shown in the statements of cash flows $ 99,194 $ 151,128 Amounts included in restricted cash represent those amounts required to be held as a security deposit in the form of letters of credit for the Company’s leased office facility and cash collateral held by credit card.
Concentrations of credit risk	Concentrations of credit risk The Company, at times, maintains cash and cash equivalents in accounts with a financial institution in excess of the amount insured by the Federal Deposit Insurance Corporation. The Company monitors the financial stability of this institution regularly and management does not believe there is significant credit risk associated with deposits in excess of federally insured amounts.
Fair value of financial instruments	Fair value of financial instruments ASC 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three‑tier fair value hierarchy that distinguishes between the following: · 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. There were no Level 3 assets or liabilities as of December 31, 2019 or 2018. 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.
Property and equipment	Property and equipment Property and equipment are stated at cost. Maintenance and repairs are charged to expense as incurred. Additions, improvements and replacements are capitalized. Depreciation of property and equipment is provided for by the straight‑line method over the estimated useful lives of the related assets. The estimated useful lives of property and equipment are as follows: Description Estimated useful life Computer software and equipment 3 years Office equipment and furniture 5 years Laboratory equipment 5 years Leasehold improvements Lesser of the estimated useful life or term of the lease Construction-in-progress reflects property and equipment yet to be placed in service.
Impairment of long-lived assets	Impairment of long‑lived assets Long‑lived assets consist of property and equipment. Long‑lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. If the sum of the estimated future undiscounted cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset group, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset group. The Company has not recorded any impairment losses on long‑lived assets for the years ended December 31, 2019 and 2018.
Research and development	Research and development Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries and benefits, facilities costs, overhead costs, depreciation, contract services and other related costs. Research and development costs are expensed to operations as the related obligation is incurred. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and are reflected on the balance sheet as prepaid or accrued expenses. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.
Convertible preferred stock	Convertible preferred stock The Company has applied the guidance in ASC 480‑10‑S99‑3A, SEC Staff Announcement: Classification and Measurement of Redeemable Securities and has therefore classified the Series A‑1, Series A‑2 and Series B convertible preferred stock (Note 10) as mezzanine equity. The convertible preferred stock was recorded outside of stockholders’ deficit because, in the event of certain deemed liquidation events considered not solely within the Company’s control, such as a merger, acquisition and sale of all or substantially all of the Company’s assets, the convertible preferred stock would have become redeemable at the option of the holders. In the event of a change of control of the Company, proceeds received from the sale of such shares will be distributed in accordance with the liquidation preferences set forth in the Company’s Amended and Restated Certificate of Incorporation. The Company determined not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because of the uncertainty of whether or when such an event would occur. As described in Note 1, all previously outstanding convertible preferred stock was converted to common stock upon the completion of the Company’s IPO in June 2018.
Stock-based compensation	Stock‑based compensation The Company has stock‑based compensation plans that cover the Company’s directors and employees and are more fully described in Note 11. Stock‑based compensation cost is estimated at the grant date based on the fair value of the award, and the cost is recognized as expense ratably over the vesting period.
Income taxes	Income taxes The Company accounts for income taxes under the liability method in accordance with FASB ASC 740, Income Taxes. Under this method, deferred income tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. A valuation allowance is established if it is more likely than not that all, or some portion, of deferred income tax assets will not be realized. The Company has recorded a full valuation allowance to reduce its net deferred income tax assets to zero. In the event the Company were to determine that it would be able to realize some or all its deferred income tax assets in the future, an adjustment to the deferred income tax asset valuation allowance would increase income in the period such determination was made. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. Any recognized income tax positions would be measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement would be reflected in the period in which the change in judgment occurs. At December 31, 2019 and 2018, the Company had no liability for income tax associated with uncertain tax positions. The Company would recognize any corresponding interest and penalties associated with its income tax positions in income tax expense. There was no income tax interest or penalties incurred in 2019 or 2018.
Segment data	Segment data The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is on advancing therapies to treat disorders of the brain and nervous system. All tangible assets are held in the United States and all revenue is generated in the United States.
Comprehensive loss	Comprehensive loss Comprehensive loss is equal to net loss as presented in the accompanying statements of operations.
Net loss per share	Net loss per share Basic net loss per share is calculated by dividing the net loss by the weighted‑average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the Company has reported net losses for each period presented.

Summary of significant accoun_3

Summary of significant accounting policiess (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of significant accounting policies
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 statements of cash flows (amounts in thousands). As of December 31, Cash and cash equivalents $ 98,849 $ 150,637 Short-term and long-term restricted cash 345 491 Total cash, cash equivalents, and restricted cash shown in the statements of cash flows $ 99,194 $ 151,128
Schedule of estimated useful lives of assets	Description Estimated useful life Computer software and equipment 3 years Office equipment and furniture 5 years Laboratory equipment 5 years Leasehold improvements Lesser of the estimated useful life or term of the lease

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair value measurements
Schedule of assets measured at fair value	Assets measured at fair value as of December 31, 2019 are as follows (in thousands): December 31, Level 1 Level 2 Level 3 Assets Money market funds, included in cash and cash equivalents $ 97,998 $ 97,998 $ — $ — Money market funds, included in restricted cash 179 179 — — Money market funds, included in other assets 166 166 — — $ 98,343 $ 98,343 $ — $ — Assets measured at fair value as of December 31, 2018 are as follows (in thousands): December 31, Level 1 Level 2 Level 3 Assets Money market funds, included in cash and cash equivalents $ 150,151 $ 150,151 $ — $ — Money market funds, included in restricted cash 252 252 — — Money market funds, included in other assets 239 239 — — $ 150,642 $ 150,642 $ — $ —

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	12 Months Ended
	Dec. 31, 2019
Prepaid expenses and other current assets
Schedule of prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following (in thousands): As of December 31, Prepaid clinical $ 3,719 $ 728 Prepaid insurance 994 673 Prepaid manufacturing costs 558 — Other prepaid expenses and current assets 366 383 Total prepaid expenses and other current assets $ 5,637 $ 1,784

Property and equipment (Tables)

Property and equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property and equipment
Schedule of property and equipment	Property and equipment are as follows (in thousands): As of December 31, Computer software and equipment $ 15 $ 15 Office equipment and furniture 176 176 Laboratory equipment 1,597 1,571 Leasehold improvements 1,051 1,051 Construction-in-progress 11 — Less accumulated depreciation (1,646) (1,123) Property and equipment, net $ 1,204 $ 1,690

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Accrued expenses and other current liabilities
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): As of December 31, Employee-related expenses $ 1,925 $ 2,043 Development costs and sponsored research 652 915 Clinical trials 410 607 Other 354 431 Total accrued expenses and other current liabilities $ 3,341 $ 3,996

Operating leases (Tables)

Operating leases (Tables)	12 Months Ended
	Dec. 31, 2019
Operating leases
Schedule of aggregate future minimum annual rental commitments under non-cancelable lease agreements	Aggregate future minimum annual rental commitments under these non‑cancelable lease agreements are as follows at December 31, 2019 (in thousands): Year ending December 31, 2020 $ 864 2021 876 2022 590 2023 — 2024 — Thereafter — $ 2,330

Convertible preferred stock a_2

Convertible preferred stock and stockholders’ equity (Tables)	12 Months Ended
	Dec. 31, 2019
Convertible preferred stock and stockholders’ equity
Schedule of the Company's common stock reserved for issuance, on an as if converted basis,	As of December 31, 2019 and 2018, the Company had reserved common stock for issuance as follows (in thousands): As of December 31, Stock options issued and outstanding 4,798 3,959 Unvested restricted stock 1,032 195 5,830 4,154

Stock incentive plan (Tables)

Stock incentive plan (Tables)	12 Months Ended
	Dec. 31, 2019
Stock incentive plan
Schedule of available shares for grant under the Company’s stock option plan	The number of shares available for grant under the Company’s stock option plan were as follows (in thousands): Available for grant as of January 1, 2018 2,419 Plan amendment 3,899 Grants (2,515) Forfeitures and cancellations 14 Available for grant as of December 31, 2018 3,817 Plan amendment 1,341 Grants (2,955) Forfeitures and cancellations 878 Available for grant as of December 31, 2019 3,081
Allocation of stock-based compensation expenses	Non‑cash stock‑based compensation expense recognized in the accompanying statements of operations relating to both stock options and restricted stock awards for the years ended December 31, 2019 and 2018 are as follows (in thousands): Year ended December 31, Research and development $ 2,442 $ 866 General and administrative 6,594 2,452 Total stock‑based compensation expense $ 9,036 $ 3,318
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, 2018 - $ - Issued 1,183 $ 3.63 Vested (26) 3.63 Forfeited and canceled (125) 3.63 Unvested as of December 31, 2019 1,032 $ 3.63
Schedule of assumptions used to determine the fair value of the stock options granted	Year ended December 31, Expected volatility 71%-75% Expected dividends None None Expected option life 5.00 - 6.08 Years 6.08 Years Risk-free rate 1.38 – 2.72% 2.81 – 3.06%
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, January 1, 2018 1,498 $ 2.48 8.93 $ 4,146 Granted 2,515 10.40 Exercised (40) 2.57 Forfeited and canceled (14) 4.79 Outstanding, December 31, 2018 3,959 $ 7.46 8.79 $ 35,984 Granted 1,772 12.19 Exercised (181) 2.07 Forfeited and canceled (752) 11.70 Outstanding, December 31, 2019 4,798 $ 8.75 8.29 $ 1,159 Vested and expected to vest at December 31, 2019 4,798 $ 8.75 8.29 $ 1,159 Exercisable at December 31, 2019 2,139 $ 5.64 7.87 $ 928

Net loss per share (Tables)

Net loss per share (Tables)	12 Months Ended
	Dec. 31, 2019
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 years ended December 31, 2019 and 2018 (in thousands, except per share data): Year ended December 31, Numerator: Net loss attributable to common stockholders $ (57,410) $ (53,281) Denominator: Weighted-average common shares outstanding—basic and diluted 33,556 20,199 Net loss per share attributable to common stockholders—basic and diluted $ (1.71) $ (2.64)
Schedule of anti-dilutive securities excluded from computation of diluted net loss per share	The following common stock equivalents outstanding as of December 31, 2019 and 2018, 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 December 31, Stock options issued and outstanding 4,798 3,959 Unvested restricted stock 1,032 195 5,830 4,154

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income taxes
Summary of reconciliation of U.S. statutory rate to the Company’s effective tax rate	Year ended December 31, Federal rate 21.0 % 21.0 % State rate 7.5 7.5 Valuation allowance (28.6) (26.8) Other 0.1 (1.7) — % — %
Schedule of significant components of the Company’s net deferred tax assets	The significant components of the Company’s net deferred tax assets are as follows (in thousands): December 31, Deferred tax assets Net operating loss $ 41,727 $ 27,749 Stock‑based compensation 2,603 — Accrued clinical trials 176 322 Accrued compensation 509 582 Accrued expenses and other, net 383 374 Total deferred tax assets 45,398 29,027 Less valuation allowance (45,398) (28,963) Net deferred tax assets — 64 Deferred tax liabilities Stock‑based compensation and other, net — (64) Net deferred taxes $ — $ —

Organization (Details)

Organization (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 25, 2018	Jun. 07, 2018	Dec. 31, 2019	Dec. 31, 2018
Organization
Accumulated deficit			$ (162,900)
Cash and cash equivalents			$ 98,849	$ 150,637
Expected period of sufficient funds for planned operations			12 months
Payment of offering costs			$ 182	$ 3,012
Reverse stock split ratio		0.03625
Preferred stock, shares authorized			10,000,000	10,000,000
Preferred stock, par value (in dollars per share)			$ 0.01	$ 0.01
Preferred stock, shares issued			0	0
Preferred stock, shares outstanding			0	0
IPO
Organization
Common stock issued and sold in initial public offering (in shares)	7,359,998
Public offering price of the shares sold	$ 16
Net proceeds from issuance of common stock	$ 106,500
Payment of offering costs	$ 3,000
Number of preferred stock converted into common stock	20,306,497
Underwriters' option
Organization
Common stock issued and sold in initial public offering (in shares)	959,999

Summary of significant accoun_4

Summary of significant accounting policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)customer	Dec. 31, 2018USD ($)customer
Concentration Risk [Line Items]
Allowance for accounts receivable	$ 0	$ 0
Accounts receivable	$ 444	$ 578
Customer Concentration Risk | Revenue | Allergan
Concentration Risk [Line Items]
Number of customers | customer	1	1
Concentration risk percentage	100.00%	75.00%
Customer Concentration Risk | Accounts Receivable | Allergan
Concentration Risk [Line Items]
Accounts receivable	$ 400	$ 600

Summary of significant accoun_5

Summary of significant accounting policies - Cash, cash equivalents, and restricted cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of significant accounting policies
Cash and cash equivalents	$ 98,849	$ 150,637
Short-term and long-term restricted cash	345	491
Total cash, cash equivalents, and restricted cash shown in the statements of cash flows	$ 99,194	$ 151,128	$ 92,609

Summary of significant accoun_6

Summary of significant accounting policies - Property and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Impairment of long lived assets	$ 0	$ 0
Computer software and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Laboratory equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Level 3
Property, Plant and Equipment [Line Items]
Assets measured at fair value	$ 0	0
Liabilities measured at fair value	$ 0	$ 0

Summary of significant accoun_7

Summary of significant accounting policies - Income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Summary of significant accounting policies
Deferred income tax assets	$ 0
Uncertain tax positions	0	$ 0
Interest or penalties recorded	$ 0	$ 0

Research collaboration agreem_2

Research collaboration agreement with Allergan (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Jul. 24, 2015USD ($)Option
Research collaboration agreement with Allergan
Research and development	$ 44,330	$ 48,788
Non-Refundable Milestone Payment		1,000
RCA
Research collaboration agreement with Allergan
Payment of option exercise fee			$ 1,000
Number of options to acquire molecules | Option			3
capitalized contract costs	0
Research and development	$ 7,300	$ 7,900
Development activities reimbursement percentage	50.00%	50.00%
Development activities expenses reimbursed	$ 3,700	$ 3,900
Remaining performance obligation		$ 0

Fair value measurements (Detail

Fair value measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Level 3
Fair value measurements
Assets measured at fair value	$ 0	$ 0
Recurring
Fair value measurements
Assets measured at fair value	98,343	150,642
Recurring | Money market funds, included in cash and cash equivalents
Fair value measurements
Money market funds	97,998	150,151
Recurring | Money market funds, included in restricted cash
Fair value measurements
Money market funds	179	252
Recurring | Money market funds, included in other assets
Fair value measurements
Money market funds	166	239
Recurring | Level 1
Fair value measurements
Assets measured at fair value	98,343	150,642
Recurring | Level 1 | Money market funds, included in cash and cash equivalents
Fair value measurements
Money market funds	97,998	150,151
Recurring | Level 1 | Money market funds, included in restricted cash
Fair value measurements
Money market funds	179	252
Recurring | Level 1 | Money market funds, included in other assets
Fair value measurements
Money market funds	$ 166	$ 239

Prepaid expenses and other cu_3

Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Prepaid expenses and other current assets
Prepaid clinical	$ 3,719	$ 728
Prepaid insurance	994	673
Prepaid Manufacturing Cost	558
Other prepaid expenses and current assets	366	383
Total prepaid expenses and other current assets	$ 5,637	$ 1,784

Property and equipment (Details

Property and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property and equipment
Less accumulated depreciation	$ (1,646)	$ (1,123)
Property and equipment, net	1,204	1,690
Depreciation and amortization	455	457
Computer software and equipment
Property and equipment
Property and equipment, gross	15	15
Office equipment and furniture
Property and equipment
Property and equipment, gross	176	176
Laboratory equipment
Property and equipment
Property and equipment, gross	1,597	1,571
Leasehold improvements
Property and equipment
Property and equipment, gross	1,051	$ 1,051
Construction in progress
Property and equipment
Property and equipment, gross	$ 11

Accrued expenses and other cu_3

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued expenses and other current liabilities
Employee-related expenses	$ 1,925	$ 2,043
Development costs and sponsored research	652	915
Clinical trials	410	607
Other	354	431
Total accrued expenses and other current liabilities	$ 3,341	$ 3,996

Operating leases (Details)

Operating leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Jul. 18, 2018ft²	Oct. 13, 2016USD ($)ft²item
Operating leases
Leased space (in square feet) | ft²			6,172	16,500
Lease renewal options | item				1
Renewal term (in years)				5 years
Deferred lease incentive				$ 400
Rent expense inclusive of lease incentives	$ 900	$ 700
Future minimum annual rental commitments
2020	864
2021	876
2022	590
Total	$ 2,330

Convertible preferred stock a_3

Convertible preferred stock and stockholders’ equity - Convertible preferred stock (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 11, 2017	May 04, 2016
Series A Preferred Stock | Private placement
Temporary Equity [Line Items]
Shares authorized		325,225,719
Series A‑1 | Private placement
Temporary Equity [Line Items]
Shares authorized		151,772,701
Issuance price per share		$ 0.16472
Series A‑1 | Private placement | Maximum
Temporary Equity [Line Items]
New shares issued under the agreement		151,772,701
Series A‑2
Temporary Equity [Line Items]
Issuance price per share		$ 0.23061
Series A‑2 | Private placement
Temporary Equity [Line Items]
Shares authorized		173,453,018
Issuance price per share		$ 0.23061
New shares issued under the agreement		173,453,018
Series B preferred stock
Temporary Equity [Line Items]
Shares authorized	234,954,520
Cash proceeds, net of issuance cost	$ 69.8
Series B preferred stock | Private placement
Temporary Equity [Line Items]
Issuance price per share	$ 0.29793
New shares issued under the agreement	234,954,520

Convertible preferred stock a_4

Convertible preferred stock and stockholders’ equity - Conversion update, Voting rights (Details) $ / shares in Units, $ in Millions	Dec. 11, 2017USD ($)Vote$ / sharesshares	May 04, 2016Vote$ / shares
Threshold gross proceeds for automatic conversion | $	$ 70
Threshold share price for automatic conversion	$ 0.446895
Series A Preferred Stock
Number of votes per share | Vote		1
Number of director entitled to be elected by preferred shareholders | Vote		4
Series A‑1
Conversion price		$ 0.16472
Series A‑2
Conversion price		$ 0.23061
Series B preferred stock
Conversion price	$ 0.29793
Approval of threshold shares | shares	30,208,439
Number of votes per share | Vote	1

Convertible preferred stock a_5

Convertible preferred stock and stockholders’ equity - Common stock (Details) - shares shares in Thousands	Dec. 31, 2019	Dec. 31, 2018
Common stock reserved for issuance	5,830	4,154
Stock options
Common stock reserved for issuance	4,798	3,959
Restricted stock awards
Common stock reserved for issuance	1,032	195

Stock incentive plan (Details)

Stock incentive plan (Details) - shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards available for future grant	3,081,000	3,817,000	2,419,000
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards available for future grant	3,079,544
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards available for future grant	505,046

Stock incentive plan - Shares a

Stock incentive plan - Shares available for grant (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for grant Beginning of the period	3,817	2,419
Plan amendment	1,341	3,899
Grants	(2,955)	(2,515)
Forfeitures and cancellations	878	14
Available for grant End of the period	3,081	3,817
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants	(1,772)	(2,515)
Forfeitures and cancellations	752	14

Stock incentive plan - Stock-ba

Stock incentive plan - Stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 9,036	$ 3,318
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,442	866
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,594	$ 2,452

Stock incentive plan - Restrict

Stock incentive plan - Restricted stock awards (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash restricted stock unit award expense recognized	$ 9,036	$ 3,318
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			1,500,000
Granted (in dollars per share)			$ 1.10
Vesting period			4 years
Non-cash restricted stock unit award expense recognized	200	$ 300
Fair value of shares vested	$ 200
Vested (in shares)	195,000
Unvested restricted stock outstanding		195,000

Stock incentive plan - Restri_2

Stock incentive plan - Restricted stock units (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Weighted-average grant date fair value per share
Non-cash restricted stock unit award expense recognized		$ 9,036	$ 3,318
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	2 years
Vested and outstanding awards		21,764
Shares
Issued (in shares)	1,183,400	1,183,000
Vested		(26,000)
Forfeited and canceled (in shares)		(125,000)
Unvested at end of period (in shares)		1,032,000
Weighted-average grant date fair value per share
Issued (in dollars per share)		$ 3.63
Vested (in dollars per share)		3.63
Forfeited and canceled (in dollars per share)		3.63
Unvested at end of period (in dollars per share)		$ 3.63
Non-cash restricted stock unit award expense recognized		$ 1,300
Unrecognized compensation related to unvested restricted stock units		$ 2,600
Expenses recognized over a weighted-average period (in years)		1 year 4 months 17 days

Stock incentive plan - Fair val

Stock incentive plan - Fair value assumptions (Details) - Stock options	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		75.00%
Expected dividends	0.00%	0.00%
Expected option life		6 years 29 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	71.00%
Expected option life	5 years
Risk-free rate	1.38%	2.81%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	75.00%
Expected option life	6 years 29 days
Risk-free rate	2.72%	3.06%

Stock incentive plan - Activity

Stock incentive plan - Activity related to stock options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Shares
Granted	2,955	2,515
Forfeited and canceled	(878)	(14)
Stock options
Shares
Outstanding, at the beginning of the period	3,959	1,498
Granted	1,772	2,515
Exercised	(181)	(40)
Forfeited and canceled	(752)	(14)
Outstanding, at the end of the period	4,798	3,959	1,498
Vested and expected to vest	4,798
Exercisable	2,139
Weighted-average exercise price
Outstanding, at the beginning of the period	$ 7.46	$ 2.48
Granted	12.19	10.40
Exercised	2.07	2.57
Forfeited and canceled	11.70	4.79
Outstanding, at the end of the period	8.75	$ 7.46	$ 2.48
Vested and expected to vest	8.75
Exercisable at the end of the period	$ 5.64
Weighted-average remaining contractual term
Weighted-average remaining contractual term	8 years 3 months 15 days	8 years 9 months 15 days	8 years 11 months 5 days
Vested and expected to vest	8 years 3 months 15 days
Exercisable	7 years 10 months 13 days
Aggregate intrinsic value
Outstanding, at the beginning of the period	$ 35,984	$ 4,146
Outstanding, at the end of the period	1,159	$ 35,984	$ 4,146
Vested and expected to vest	1,159
Exercisable	$ 928
Weighted-average grant date fair value per share	$ 7.98	$ 7.03
Unrecognized stock-based compensation related to non-vested stock options	$ 17,500
Expenses recognized over a weighted-average period (in years)	2 years 8 months 5 days
Term of award	10 years
Vesting period	4 years

Stock incentive plan - Employee

Stock incentive plan - Employee Stock Purchase Plan (Details) - shares	Jun. 05, 2018	Dec. 31, 2019	Dec. 31, 2018
Subsidiary, Sale of Stock [Line Items]
Common stock reserved for issuance		5,830,000	4,154,000
Employee Stock Purchase Plan
Subsidiary, Sale of Stock [Line Items]
Common stock reserved for issuance	314,697
Maximum percentage increase in shares available for issuance under the ESPP	1.00%

Net loss per share (Details)

Net loss per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss attributable to common stockholders	$ (57,410)	$ (53,281)
Denominator:
Weighted-average common shares outstanding—basic and diluted	33,556	20,199
Net loss per share attributable to common stockholders—basic and diluted	$ (1.71)	$ (2.64)

Net loss per share - Anti-dilut

Net loss per share - Anti-dilutive securities (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
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	5,830	4,154
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	4,798	3,959
Unvested restricted stock
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	1,032	195

Employee benefit plan (Details)

Employee benefit plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Employee benefit plan
Matching contribution as a percentage	4.00%
Matching contributions	$ 0.4	$ 0.3

Income taxes (Details)

Income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income taxes
Federal effective tax rate	21.00%	21.00%
Income taxes	$ 0

Income taxes - Deferred tax ass

Income taxes - Deferred tax assets and valuation allowance (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Federal
Operating Loss Carryforwards [Line Items]
Net operating losses	$ 146.4
NOL Gross	7.1
Net operating loss carryforwards that expire	49
Net operating losses that never expire	$ 97.4
Net operating loss carryforward taxable income limit percentage	80.00%
State
Operating Loss Carryforwards [Line Items]
NOL carryforward period	12 years
Net operating loss carryforwards that expire	$ 13.9

Income taxes - Reconciliation (

Income taxes - Reconciliation (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income taxes
Federal rate	21.00%	21.00%
State rate	7.50%	7.50%
Valuation allowance	(28.60%)	(26.80%)
Other	0.10%	(1.70%)

Income taxes - Components of ne

Income taxes - Components of net deferred tax assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Net operating loss	$ 41,727	$ 27,749
Stock‑based compensation	2,603
Accrued clinical trials	176	322
Accrued compensation	509	582
Accrued expenses and other, net	383	374
Total deferred tax assets	45,398	29,027
Less valuation allowance	(45,398)	(28,963)
Net deferred tax assets		64
Deferred tax liabilities
Stock-based compensation and other, net		(64)
Net deferred taxes	$ 0
Net operating loss carryforwards with no taxable income limitation		$ 7,100

Subsequent events (Details)

Subsequent events (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 14, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Granted		2,955,000	2,515,000
Subsequent Event | Sales Agreement
Subsequent Event [Line Items]
New shares issued under the agreement	11,691,666
Public offering price of the shares sold	$ 3
Net proceeds from issuance of common stock	$ 33.3