Axsome Therapeutics (AXSM) 10-Q 9 Aug 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 02, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2021
Entity File Number	001-37635
Entity Registrant Name	AXSOME THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-4241907
Entity Address, Address Line One	22 Cortlandt Street
Entity Address, Address Line Two	16th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10007
City Area Code	212
Local Phone Number	332-3241
Title of 12(b) Security	Common Stock, Par Value $0.0001 Per Share
Trading Symbol	AXSM
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		37,681,948
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001579428
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 141,219,090	$ 183,876,453
Prepaid and other current assets	435,804	148,373
Total current assets	141,654,894	184,024,826
Equipment, net	83,444	52,647
Right-of-use asset - operating lease	1,209,037	1,739,475
Other assets	317,375	317,375
Total assets	143,264,750	186,134,323
Current liabilities:
Accounts payable	11,611,996	13,504,022
Accrued expenses and other current liabilities	10,162,831	8,713,249
Operating lease liability, current portion	1,088,841	1,220,587
Total current liabilities	22,863,668	23,437,858
Loan payable, long-term	48,882,599	48,321,848
Operating lease liability, long-term	81,863	581,708
Total liabilities	71,828,130	72,341,414
Stockholders’ equity:
Preferred stock, $0.0001 par value per share (10,000,000 shares authorized, none issued and outstanding at June 30, 2021 and December 31, 2020, respectively)
Common stock, $0.0001 par value per share (150,000,000 shares authorized, 37,648,948 and 37,374,088 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively)	3,765	3,737
Additional paid-in capital	411,773,127	392,585,265
Accumulated deficit	(340,340,272)	(278,796,093)
Total stockholders’ equity	71,436,620	113,792,909
Total liabilities and stockholders’ equity	$ 143,264,750	$ 186,134,323

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	37,648,948	37,374,088
Common stock, shares outstanding	37,648,948	37,374,088

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating expenses:
Research and development	$ 14,503,326	$ 10,542,957	$ 31,099,014	$ 38,064,357
General and administrative	16,344,361	7,235,877	27,592,734	12,205,934
Total operating expenses	30,847,687	17,778,834	58,691,748	50,270,291
Loss from operations	(30,847,687)	(17,778,834)	(58,691,748)	(50,270,291)
Interest and amortization of debt discount (expense) income	(1,436,522)	(548,158)	(2,852,431)	(540,847)
Net loss	$ (32,284,209)	$ (18,326,992)	$ (61,544,179)	$ (50,811,138)
Net loss per common share, basic and diluted	$ (0.86)	$ (0.49)	$ (1.64)	$ (1.37)
Weighted average common shares outstanding, basic and diluted	37,595,069	37,100,770	37,512,716	37,081,064

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2019	$ 178,722,389	$ 3,693	$ 354,614,189	$ (175,895,493)
Balance (in shares) at Dec. 31, 2019		36,933,217
Stock-based compensation	2,133,530		2,133,530
Issuance of common stock upon exercise of options	629,756	$ 6	629,750
Issuance of common stock upon exercise of options (in shares)		60,186
Issuance of common stock upon financing	7,155,337	$ 8	7,155,329
Issuance of common stock upon financing (in shares)		82,019
Net loss	(32,484,146)			(32,484,146)
Ending balance at Mar. 31, 2020	156,156,866	$ 3,707	364,532,798	(208,379,639)
Balance (in shares) at Mar. 31, 2020		37,075,422
Beginning balance at Dec. 31, 2019	178,722,389	$ 3,693	354,614,189	(175,895,493)
Balance (in shares) at Dec. 31, 2019		36,933,217
Net loss	(50,811,138)
Ending balance at Jun. 30, 2020	154,243,310	$ 3,726	380,946,215	(226,706,631)
Balance (in shares) at Jun. 30, 2020		37,267,510
Beginning balance at Mar. 31, 2020	156,156,866	$ 3,707	364,532,798	(208,379,639)
Balance (in shares) at Mar. 31, 2020		37,075,422
Stock-based compensation	4,148,025		4,148,025
Issuance of common stock upon exercise of options	190,409	$ 2	190,407
Issuance of common stock upon exercise of options (in shares)		20,428
Issuance of common stock upon exercise of warrants	3	$ 3
Issuance of common stock upon exercise of warrants (in shares)		29,982
Issuance of common stock upon financing	12,074,999	$ 14	12,074,985
Issuance of common stock upon financing (in shares)		141,678
Net loss	(18,326,992)			(18,326,992)
Ending balance at Jun. 30, 2020	154,243,310	$ 3,726	380,946,215	(226,706,631)
Balance (in shares) at Jun. 30, 2020		37,267,510
Beginning balance at Dec. 31, 2020	$ 113,792,909	$ 3,737	392,585,265	(278,796,093)
Balance (in shares) at Dec. 31, 2020	37,374,088	37,374,088
Stock-based compensation	$ 3,731,097		3,731,097
Issuance of common stock upon exercise of options	1,913,299	$ 10	1,913,289
Issuance of common stock upon exercise of options (in shares)		94,000
Issuance of common stock upon vesting of RSUs (in shares)		1,917
Issuance of common stock upon financing	6,115,864	$ 9	6,115,855
Issuance of common stock upon financing (in shares)		93,877
Net loss	(29,259,970)			(29,259,970)
Ending balance at Mar. 31, 2021	96,293,199	$ 3,756	404,345,506	(308,056,063)
Balance (in shares) at Mar. 31, 2021		37,563,882
Beginning balance at Dec. 31, 2020	$ 113,792,909	$ 3,737	392,585,265	(278,796,093)
Balance (in shares) at Dec. 31, 2020	37,374,088	37,374,088
Issuance of common stock upon exercise of options (in shares)	162,503
Net loss	$ (61,544,179)
Ending balance at Jun. 30, 2021	$ 71,436,620	$ 3,765	411,773,127	(340,340,272)
Balance (in shares) at Jun. 30, 2021	37,648,948	37,648,948
Beginning balance at Mar. 31, 2021	$ 96,293,199	$ 3,756	404,345,506	(308,056,063)
Balance (in shares) at Mar. 31, 2021		37,563,882
Stock-based compensation	5,456,242		5,456,242
Issuance of common stock upon exercise of options	958,895	$ 7	958,888
Issuance of common stock upon exercise of options (in shares)		68,503
Issuance of common stock upon vesting of RSUs		$ 0
Issuance of common stock upon vesting of RSUs (in shares)		144
Issuance of common stock upon financing	1,096,503	$ 2	1,096,501
Issuance of common stock upon financing (in shares)		16,419
Shares tendered for withholding taxes	(84,010)	$ 0	(84,010)
Net loss	(32,284,209)			(32,284,209)
Ending balance at Jun. 30, 2021	$ 71,436,620	$ 3,765	$ 411,773,127	$ (340,340,272)
Balance (in shares) at Jun. 30, 2021	37,648,948	37,648,948

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net loss	$ (61,544,179)	$ (50,811,138)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	9,187,339	6,281,555
Non-cash research and development license expense		7,155,337
Amortization of debt discount	560,752	356,664
Amortization of operating lease right-of-use asset	530,437
Change in operating lease liability	(631,591)
Depreciation	18,075	10,960
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(287,431)	275,914
Accounts payable	(1,892,026)	(1,580,100)
Accrued expenses and other current liabilities	1,449,582	(3,857,658)
Net cash used in operating activities	(52,609,042)	(42,168,466)
Cash flows from investing activities
Purchases of equipment	(48,872)	(10,759)
Net cash used in investing activities	(48,872)	(10,759)
Cash flows from financing activities
Proceeds from issuance of common stock upon financing, net	7,212,367	12,074,999
Proceeds from issuance of common stock upon exercise of options	2,872,194	820,165
Proceeds from issuance of common stock upon exercise of warrants		3
Payments of tax withholdings on stock award	(84,010)
Net cash (used in) provided by financing activities	10,000,551	12,895,167
Net (decrease) increase in cash	(42,657,363)	(29,284,058)
Cash at beginning of period	183,876,453	219,966,167
Cash at end of period	141,219,090	190,682,109
Supplemental disclosures of cash flow information:
Interest paid	$ 2,312,917	$ 762,501

Nature of Business and Basis of

Nature of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Note 1. Nature of Business and Basis of Presentation Axsome Therapeutics, Inc. (“Axsome” or the “Company”) is a biopharmaceutical company developing novel therapies for central nervous system (“CNS”) disorders for which there are limited treatment options. By focusing on this therapeutic area, the Company is addressing significant and growing markets where current treatment options are limited or inadequate. The Company’s core CNS portfolio includes five product candidates, AXS-05, AXS-07, AXS-09, AXS-12, and AXS-14, which are being developed for multiple indications. The Company aims to become a fully integrated biopharmaceutical company that develops and commercializes differentiated therapies that expand the treatment options available to caregivers and improve the lives of patients living with CNS disorders. The Company was incorporated on January 12, 2012 in the State of Delaware. The accompanying unaudited interim consolidated financial statements have been prepared by the Company in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim information and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting on Form 10-Q. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited interim consolidated financial statements should be read in conjunction with the audited financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 1, 2021. In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments, which are normal recurring adjustments, necessary for the fair presentation of the financial information for the interim periods. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the operating results for the full fiscal year or any future period. Liquidity and Capital Resources The Company has incurred operating losses since its inception, and expects to continue to incur operating losses for the foreseeable future and may never become profitable. As of June 30, 2021, the Company had an accumulated deficit of $340.3 million. The Company’s primary sources of cash have been proceeds from the issuance and sale of its common stock in public offerings. The Company has not yet commercialized any of its product candidates and cannot be sure if it will ever be able to do so. The Company’s ability to achieve profitability depends on a number of factors, including its ability to obtain regulatory approval for its product candidates, successfully complete any post-approval regulatory obligations and successfully commercialize its product candidates alone or in partnership. The Company may continue to incur substantial operating losses even if it begins to generate revenues from its product candidates. The Company believes its existing cash will be sufficient to fund its anticipated operating cash requirements for at least twelve months following the date of this filing. The actual amount of cash that the Company will need to operate is subject to many factors, including, but not limited to, the timing, design and conduct of clinical trials for its product candidates. The Company may use a combination of public and private equity offerings, debt financings, other third-party funding, strategic alliances, licensing arrangements or marketing and distribution arrangements if market conditions are favorable or in light of other strategic considerations to finance its future cash needs. The Company’s common stock is listed on Impact of COVID-19 In December 2019, a novel (new) coronavirus known as SARS-CoV-2 was first detected in Wuhan, Hubei Province, People’s Republic of China, causing outbreaks of the coronavirus disease, known as COVID-19, that has now spread globally. On January 30, 2020, the World Health Organization (WHO) declared COVID-19 a public health emergency. The Secretary of Health and Human Services declared a public health emergency in the United States on January 31, 2020, under section 319 of the Public Health Service Act (42 U.S.C. 247d), in response to the COVID-19 outbreak. On March 11, 2020, the WHO declared COVID-19 a pandemic. The full impact of the COVID-19 pandemic is unknown and rapidly evolving. While the potential economic impact brought by and over the duration of the COVID-19 pandemic may be difficult to assess or predict, the COVID-19 pandemic has resulted in significant disruption of global financial markets, which could in the future negatively affect the Company’s liquidity. In addition, a recession or market volatility resulting from the COVID-19 pandemic could affect the Company’s business. Given the nature and type of the Company’s short-term investments, the Company does not believe the COVID-19 pandemic has had or will have a material impact on the Company’s current investment liquidity.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Significant Risks and Uncertainties The Company’s operations are subject to a number of factors that can affect its operating results and financial condition. Such factors include, but are not limited to: the results of clinical testing and trial activities of the Company’s product candidates; the Company’s ability to obtain regulatory approval to market its products, if approved; competition from products manufactured and sold or being developed by other companies; the price of, and demand for, the Company’s products, if approved; the Company’s ability to negotiate favorable licensing or other manufacturing and marketing agreements for its products, if approved; and the Company’s ability to raise additional financing. If the Company does not successfully commercialize any of its product candidates, it will be unable to generate recurring product revenue or achieve and maintain profitability. Use of Estimates Management considers many factors in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. In preparing these financial statements, management used significant estimates in the following areas, among others: stock‑based compensation expense; the determination of the fair value of the warrants; the accounting for research and development costs; and the recoverability of the Company’s net deferred tax assets and related valuation allowance. Foreign Currency Translation Expenses denominated in foreign currency are translated into U.S. dollars at the exchange rate on the date the expense is incurred. Assets and liabilities of foreign operations are translated at period-end exchange rates. The effect of exchange rate fluctuations on translating foreign currency into U.S. dollars is included in the Statements of Operations and is not material to the Company’s financial statements. Segment and Geographic Information Operating segments are defined as components of an enterprise for which separate discrete information is available for evaluation by the chief operating decision maker or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business as one operating segment, which is the business of developing novel therapies for the management of CNS disorders. Cash Equivalents The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. The Company’s cash and cash equivalents includes holdings in checking and overnight sweep accounts. The Company’s cash equivalents, which are money market funds held in a sweep account, are measured at fair value on a recurring basis. As of June 30, 2021, the balance of cash and cash equivalents was $141.2 million, which approximates fair value and was determined based upon Level 1 inputs. The sweep account is valued using quoted market prices with no valuation adjustments applied. Accordingly, these securities are categorized as Level 1. Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash. The Company maintains its cash at financial institutions, which at times, exceed federally insured limits. At June 30, 2021, the majority of the Company’s cash was held by one financial institution and the amount on deposit was in excess of Federal Deposit Insurance Corporation insurance limits. The Company has not recognized any losses from credit risks on such accounts since inception. The Company believes it is not exposed to significant credit risk on cash. Fair Value of Financial Instruments Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three‑level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1—Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly. Level 3—Inputs that are unobservable for the asset or liability. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s financial instruments are cash, accounts payable, accrued liabilities, and current and long-term debt. The carrying values for cash, accounts payable and accrued liabilities reported in the accompanying consolidated financial statements approximate their respective fair values due to their short-term maturities. The carrying value of debt on the Company’s balance sheet (see Note 6 – Loan and Security Agreement), is estimated to approximate its fair value as the interest rate approximates the market rate for loans with similar terms and risk characteristics. Debt Issuance Costs Debt issuance costs consist of costs incurred in obtaining long-term financing. These costs are classified on the consolidated balance sheet as a direct deduction from the carrying amount of the related debt liability. These expenses are deferred and amortized as part of interest expense in the consolidated statement of operations using the effective interest rate method over the term of the debt agreement. Equipment Equipment consists primarily of computer equipment and is recorded at cost. Equipment is depreciated on a straight‑line basis over its estimated useful life, which the Company estimates to be three years. When equipment is sold or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts and the resulting gain or loss is included in operating expenses. Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses consist primarily of personnel costs for our research and development employees, costs incurred to third-party service providers for the conduct of research, preclinical and clinical studies, laboratory supplies, product license fees, consulting and other related expenses. We estimate research, preclinical and clinical study expenses based on services performed, pursuant to contracts with third-party research and development organizations that conduct and manage research, preclinical and clinical activities on our behalf. We estimate these expenses based on discussions with internal management personnel and external service providers as to the progress or stage of completion of services and the contracted fees to be paid for such services. If the actual timing of the performance of services or the level of effort varies from the original estimates, we will adjust the accrual accordingly. Payments associated with licensing agreements to acquire licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternative future use are expensed as incurred. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered. Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, operating losses, and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company estimates an annual effective tax rate of 0% for the year ending December 31, 2021 and has not recorded an income tax benefit for the six months ended June 30, 2021 and 2020 since it determined that a full valuation allowance is required against the Company’s deferred tax assets. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not to be sustained upon examination based on the technical merits of the position as well as consideration of the available facts and circumstances. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. As of June 30, 2021, the Company does not believe any material uncertain tax positions are present. In the event the Company determines that accrual of interest or penalties are necessary in the future, the amount will be presented as a component of income tax expense. Stock-Based Compensation For stock options issued, the Company estimates the grant date fair value of each option using the Black‑Scholes option pricing model. The Black-Scholes model takes into account the expected volatility of the Company’s common stock, the risk-free interest rate, the estimated life of the option, the closing market price of the Company’s common stock and the exercise price. The estimates utilized in the Black-Scholes calculation involve inherent uncertainties and the application of management’s judgment. In addition, the Company recognizes expense for equity award forfeitures as they occur. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period, which is generally the vesting term. For restricted stock units (“RSUs”), the Company issues them in the form of Company common stock. The fair market value of these awards is based on the market closing price per share on the grant date. Prior to January 1, 2020, the Company only granted stock options. Beginning in 2020, for grants to employees, the Company granted a mix of stock options and RSUs. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period, which is generally the vesting term. For awards subject to performance-based vesting conditions, the Company recognizes stock-based compensation expense using the accelerated attribution method when it is probable that the performance condition will be achieved. The expense related to the stock-based compensation is recorded within the same financial statement line item as the grantee’s cash compensation. The Company’s policy upon exercise of stock options and RSUs is that shares will be issued as new shares drawing on the Company’s 2015 Omnibus Incentive Compensation Plan share pool that was adopted by the stockholders in November 2015. Basic and Diluted Net Loss per Common Share Basic net loss per share of common stock is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as warrants, stock options, and RSUs, which would result in the issuance of incremental shares of common stock. As the impact of these items is anti-dilutive during periods of net loss, there was no difference between basic and diluted net loss per share of common stock for the three and six months ended June 30, 2021 and 2020. Leases The Company determines if an arrangement is a lease at contract inception. Operating lease assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. When evaluating whether a contract contains a lease, the Company considers whether (1) the contract explicitly or implicitly identifies assets that are contractually defined and (2) the Company obtains substantially all of the economic benefits from the use of that underlying asset and directs how and for what purpose the asset is used during the term of the contract. The Company’s lease agreement contains lease and non-lease components. Non-lease components primarily include payments for maintenance and utilities. The Company has applied the practical expedient to combine fixed payments for non-lease components with lease payments and account for them together as a single lease component, which increases the amount of lease assets and corresponding liabilities. Payments under the Company’s lease arrangement are primarily fixed, however variable payments, are expensed as incurred and not included in the operating lease asset and liability. Operating lease assets and liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The Company uses the implicit interest rate when readily determinable and uses the Company’s incremental borrowing rate when the implicit rate is not readily determinable based upon the information available at the commencement date in determining the present value of the lease payments. The Company’s operating leases are reflected in the right-of-use operating asset; operating lease liability, current portion; and operating lease liability, long-term portion in the Company’s consolidated balance sheets. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Short-term leases, defined as leases that have a lease term of 12 months or less at the commencement date, and do not include an option to extend the term or purchase the underlying asset that the Company is reasonably certain to exercise, are excluded from this treatment and are recognized on a straight-line basis over the term of the lease. Recent Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, enhances and simplifies various aspects of the income tax accounting guidance, including requirements such as tax basis step-up in goodwill obtained in a transaction that is not a business combination, ownership changes in investments, and interim-period accounting for enacted changes in tax law. ASU 2019-12 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2020. Early adoption is permitted, including adoption in an interim period. The Company adopted this standard on January 1, 2021, and the standard did not have a significant impact on its consolidated financial statements. In October 2020, the FASB issued ASU 2020-10, Codification Improvements, which clarifies various topics in the Accounting Standards Codification, including the addition of existing disclosure requirements to the relevant disclosure sections. The amendments in ASU 2020-10 do not change GAAP and, therefore, are not expected to result in a significant change in practice. ASU 2020-10 should be applied retrospectively to the beginning of the period that includes the adoption date. ASU 2020-10 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The Company adopted this standard on January 1, 2021, and the standard did not have a significant impact on its consolidated financial statements.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	6 Months Ended
	Jun. 30, 2021
Accrued Liabilities And Other Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Note 3. Accrued Expenses and Other Current Liabilities At June 30, 2021 and December 31, 2020 accrued expenses and other current liabilities consisted of the following: ​ June 30, 2021 December 31, 2020 Accrued research and development $ 2,195,033 $ 4,293,522 Accrued compensation 3,034,669 2,870,261 Accrued general and administrative 4,551,879 1,155,508 Accrued interest 381,250 393,958 Total $ 10,162,831 $ 8,713,249

Loan and Security Agreement

Loan and Security Agreement	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Loan and Security Agreement	Note 4. Loan and Security Agreement Hercules Capital, Inc. In September 2020, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Hercules Capital, Inc., in its capacity as administrative agent and collateral agent and as a lender (in such capacity, the “Agent” or “Hercules”) and the other financial institutions that from time to time become parties to the Loan Agreement as lenders (collectively, the “Lenders”). The Loan Agreement provides for term loans in an aggregate principal amount of up to $225.0 million under multiple tranches (the “2020 Term Loan”). The tranches consist of (i) a first tranche consisting of term loans in an aggregate principal amount of $60.0 million, of which $50.0 million was funded to the Company on the Closing Date (the “First Advance”), and of which the remaining $10.0 million is available at the Company’s option at any time through September 15, 2021; (ii) subject to the approval of the Company’s AXS-05 product candidate for the treatment of major depressive disorder (the “First Milestone”), a second tranche consisting of additional term loans in an aggregate principal amount of up to $35.0 million, available at the Company’s option beginning on the date that the First Milestone is achieved through the earlier of (A) 181 days following such date and (B) June 30, 2022; (iii) subject to the approval of the Company’s AXS-07 product candidate for the treatment of migraine (the “Second Milestone”), a third tranche consisting of additional term loans in an aggregate principal amount of up to $20.0 million, available at the Company’s option beginning on the date that the Second Milestone is achieved through the earlier of (A) 181 days following such date and (B) June 30, 2022; (iv) subject to the achievement of either the First Milestone or the Second Milestone and so long as the Company is in compliance with a required ratio of Lender indebtedness to net product revenue, a fourth tranche consisting of additional term loans in an aggregate principal amount of up to $60.0 million, available at the Company’s option beginning on January 1, 2022 and continuing through March 31, 2023; and (v) subject to approval by the Lenders’ in their discretion, a fifth tranche of additional term loans in an aggregate principal amount of up to $50.0 million, available through December 31, 2023. The Company intends to use the proceeds of the Term Loan Advances for working capital and general corporate purposes. In addition, approximately $21.7 million of the proceeds from the First Advance was used to satisfy in full and retire the Company’s indebtedness under the 2019 Term Loan (as defined below), as amended. The outstanding principal balance of the term loans bears interest at an annual rate equal to the greater of either (i) the prime rate as reported in The Wall Street Journal The Company is required to repay the term loans in equal installments of principal and interest commencing on May 1, 2023 through October 1, 2025 (the “Maturity Date”). However, if either the First Milestone or the Second Milestone are achieved prior to May 1, 2023, and no default exists, the amortization commencement date will be automatically extended to November 1, 2023; if both the First Milestone and the Second Milestone are achieved prior to November 1, 2023, and no default exists, the amortization commencement date will be further automatically extended to May 1, 2024 and if any term loans are funded under the fourth tranche noted above prior to May 1, 2024, and no default exists, the amortization commencement date will be further automatically extended to November 1, 2024. On the Maturity Date, all unpaid term loans will be due and payable. As collateral for the obligations, the Company has granted to Hercules a senior security interest in all of Company’s right, title, and interest in, to and under all of Company’s property, inclusive of intellectual property, which includes one of the Company’s existing license agreements (the “License Agreement”) with Antecip Bioventures II LLC (“Antecip”), an entity owned by Axsome’s Chief Executive Officer and Chairman of the Board, Herriot Tabuteau, M.D., subject to limited exceptions . The Loan Agreement contains customary representations, warranties and covenants, including covenants by the Company limiting additional indebtedness, liens (including a negative pledge on intellectual property and other assets), guaranties, mergers and consolidations, substantial asset sales, investments and loans, certain corporate changes, transactions with affiliates and fundamental changes. At the initial closing, there were no applicable financial covenants contained in the Loan Agreement. Only after additional amounts are drawn down by the Company in the future, if the Company decides to do so, under the terms set forth in the Loan Agreement, there will be certain limited financial covenants that will apply, including: • Effective upon the date the outstanding principal amount of the advances under the Loan Agreement equals or exceeds $55.0 million, which has not yet occurred, the Company at all times thereafter must maintain cash in an account or accounts in which Hercules has a first priority security interest, in an aggregate amount greater than or equal to $15.0 million, plus the amount of the Company’s accounts payable under U.S. GAAP not paid after the 180th day following the invoice for such account payable (such amount, the “Qualified Cash A/P Amount”). • Effective upon the later of (i) the last calendar month of the calendar quarter that is twelve months following the earlier of (x) the date that the First Milestone is achieved and (y) the date that the Second Milestone is achieved, or (ii) the date on which the outstanding principal amount of the term loan advances under the Loan Agreement is equal to or greater than $65.0 million, neither of which have occurred yet, the Company is required to (A) ensure that at all times its market capitalization exceeds $2.0 billion, and that it maintains cash in an account which Hercules has a first priority security interest in an amount not less than 65% of the sum of the outstanding principal amount of the term loan advances plus the Qualified Cash A/P Amount, (B) ensure that at all times that it maintains cash in an account which Hercules has a first priority security interest in an amount not less than 100% of the sum of the outstanding principal amount of the term loan advances plus the Qualified Cash A/P Amount, or (C) achieve at least 60% of the net product revenue per the board of directors approved forecast solely from the sale of AXS-05 and AXS-07 (which may include royalty, profit sharing, or sales-based milestone revenue recognized in accordance with GAAP, but will not include any upfront or non-sales-based milestone payments under business development or licensing transactions), measured on a trailing six-month basis as of the date of the Company’s most recent quarterly financial statement, determined on a quarterly basis. • Restrictions on the Company’s ability to incur additional indebtedness, pay dividends, encumber its intellectual property, or engage in certain fundamental business transactions, such as mergers or acquisitions of other businesses, with certain exceptions. The Company’s obligations under the Loan Agreement are subject to acceleration upon the occurrence of specified events of default, including payment default, insolvency and a material adverse change in the Borrower’s business, operations or financial or other condition. In addition, the Company is required to pay a final payment fee equal to the greater of (A) $2,910,000 and (B) 4.85% of the aggregate amount of all term loan advances minus the aggregate amount of repayments made. The final payment fee is being accreted and amortized into interest expense using the effective interest rate method over the term of the loan. The Company may, at its option prepay the term loans in full or in part, subject to a prepayment penalty equal to (i) 2.0% of the principal amount prepaid if the prepayment occurs prior to the first anniversary of the Closing Date, (ii) 1.5% of the principal amount prepaid if the prepayment occurs on or after the first anniversary and prior to the second anniversary of the Closing Date, and (iii) 1.0% of the principal amount prepaid if the prepayment occurs on or after the second anniversary and prior to the third anniversary of the Closing Date. Silicon Valley Bank In March 2019, the Company entered into a $24.0 million growth capital term loan facility (the “2019 Term Loan”) with Silicon Valley Bank, or SVB and West River Innovation Lending Fund VIII, L.P., or WestRiver. In September 2020, the Company used a portion of the 2020 Term Loan to terminate and repay all amounts outstanding under the 2019 Term Loan and recorded a loss on extinguishment of the 2019 Term Loan. Loan Interest Expense and Amortization The Company incurred interest expense of $1,156,458 and $2,300,208 for the three and six months ended June 30, 2021 and 379,167 and 758,334 three and six months ended June 30, 2020, respectively. In addition, amortization of the final payment fee was $149,281 and $292,870 for the three and six months ended June 30, 2021 and $119,014 and $238,028 three and six months ended June 30, 2020, respectively. The outstanding debt and unamortized debt discount balances are as follows: ​ June 30, 2021 December 31, 2020 Total Outstanding Debt $ 50,000,000 $ 50,000,000 Add: accreted liability of final payment fee 444,783 151,912 Less: unamortized debt discount, long-term (1,562,184 ) (1,830,064 ) Less: current portion of long-term debt — — Loan payable, long-term $ 48,882,599 $ 48,321,848 In connection with the entry into the Hercules Term Loan, the Company issued to Hercules a warrant to purchase a number of shares of the Company’s common stock equal to 2.5% of the aggregate amount of the Term Loan Advances that are funded. Further information on warrants issued related to this loan and prior debt financings and amendments are disclosed in Note 7 - Stockholders’ Equity under the “Warrants” section. Amortization of the debt discount in relation to warrants issued as described above was $132,508 and $267,882 for the three and six months ended June 30, 2021 and $59,998 and $118,636 for the three and six months ended June 30, 2020, respectively. Scheduled Principal Payments on Outstanding Debt, as of June 30, 2021, are as follows: 2021 — 2022 — 2023 12,193,153 2024 19,761,468 2025 18,045,379 Total principal payments outstanding $ 50,000,000 The Company was in compliance with all covenants and requirements of its financing arrangements as of and during the six months ended June 30, 2021.

Net Loss per Common Share

Net Loss per Common Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Net Loss per Common Share	Note 5. Net Loss per Common Share The following table sets forth the computation of basic and diluted net loss per common share: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Basic and diluted net loss per common share: Net loss $ (32,284,209 ) $ (18,326,992 ) $ (61,544,179 ) $ (50,811,138 ) Weighted average common shares outstanding—basic and diluted 37,595,069 37,100,770 37,512,716 37,081,064 Net loss per common share—basic and diluted $ (0.86 ) $ (0.49 ) $ (1.64 ) $ (1.37 ) The following potentially dilutive securities outstanding at June 30, 2021 and 2020 have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive: June 30, 2021 2020 Stock options 4,461,985 3,979,607 Restricted stock units 309,126 150,143 Warrants 15,541 37,042 Total 4,786,652 4,166,792

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 6. Commitments and Contingencies Operating Leases For the three and six months ended June 30, 2021, the Company had the following operating lease expense: Three Months Ended June 30, Six Months Ended June 30, Statement of Operations Location 2021 2020 2021 2020 Operating lease expense General and administrative and Research and development $ 286,923 $ — $ 573,846 $ — Total operating lease expense $ 286,923 $ — $ 573,846 $ — Future minimum lease payments of the Company’s operating leases as of June 30, 2021 were as follows: 2021 $ 575,000 2022 630,000 2023 — 2024 — 2025 — Thereafter — Total lease payments 1,205,000 Less imputed interest (34,296 ) Present value of operating lease liabilities $ 1,170,704 As of June 30, 2021, the remaining lease term for our operating lease was %. The interest rate implicit in lease contracts is typically not readily determinable and as such, the Company uses its incremental borrowing rate based on the information available at the lease commencement date, which represents an internally developed rate that would be incurred to borrow, on a collateralized basis, over a similar term, an amount equal to the lease payments in a similar economic environment.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Equity	Note 7. Stockholders’ Equity Capital Structure In May 2019, the Company entered into the May 2019 Sales Agreement with SVB Leerink, pursuant to which the Company may sell up to $50 million in shares of the Company’s common stock from time to time through SVB Leerink, acting as the Company’s sales agent, in one or more at-the-market offerings utilizing the 2016 Shelf Registration Statement. SVB Leerink is entitled to receive a commission of 3.0% of the gross proceeds for any shares sold under the May 2019 Sales Agreement. Due to expiration of the 2016 Shelf Registration Statement, at the Company’s option, the shares that were unsold of approximately $29.9 million under the May 2019 Sales Agreement, may be rolled over to the December 2019 Sales Agreement (see below). In December 2019, the Company entered into the December 2019 Sales Agreement with SVB Leerink, pursuant to which the Company may sell up to $80 million in shares of the Company’s common stock from time to time through SVB Leerink, acting as the Company’s sales agent, in one or more at-the-market offerings utilizing the 2019 Shelf Registration Statement. SVB Leerink is entitled to receive a commission of 3.0% of the gross proceeds for any shares sold under the December 2019 Sales Agreement. For the six months ended June 30, 2021, the Company received approximately $7.4 million in gross proceeds through the sale of 110,296 shares, of which net proceeds were approximately $7.2 million. For the six months ended June 30, 2020, the Company received approximately $12.4 million in gross proceeds through the sale of 141,678 shares, of which net proceeds were approximately $12.1 million. In December 2019, the Company completed an underwritten public offering, whereby the Company sold 2,300,000 shares of our common stock at a public offering price of $87.00 per share. The Company received gross proceeds of approximately $200.1 million and net proceeds of approximately $187.1 million, net of underwriting discounts and offering expenses. The holders of shares of common stock are entitled to one vote for each share of common stock held at all meetings of stockholders and written actions in lieu of meetings. The holders of shares of common stock are entitled to receive dividends, if and when declared by the board of directors. Shelf Registration Statement On December 5, 2019, the Company filed an automatic shelf registration statement (“2019 Shelf Registration”) with the Securities and Exchange Commission (“SEC”) for the issuance of common stock, preferred stock, warrants, rights, debt securities and units. It became effective upon filing with the SEC and is currently the Company’s only active shelf registration. Through the date of this report, the Company has issued common stock of approximately $229.3 million pursuant to such shelf registration statement. Under SEC rules, the 2019 Shelf Registration Statement allows for the potential future offer and sale by the Company, from time to time, in one or more public offerings, of an indeterminate amount of the Company’s common stock, preferred stock, debt securities, and units at indeterminate prices. At the time any of the securities covered by the 2019 Shelf Registration Statement are offered for sale, a prospectus supplement will be prepared and filed with the SEC containing specific information about the terms of any such offering. Equity Incentive Plans There were 4,572,808 shares available for the issuance of stock options or stock-based awards under the Company’s 2015 Omnibus Incentive Compensation Plan at June 30, 2021. Stock Options The following table sets forth the stock option activity for the six months ended June 30, 2021: ​Number of shares ​Weighted average exercise price Weighted average contractual term ​Aggregate intrinsic value Outstanding at December 31, 2020 3,725,648 $ 16.36 Granted 955,213 66.05 Exercised (162,503 ) 17.67 Forfeited (55,727 ) 63.58 Expired (646 ) 87.76 Outstanding at June 30, 2021 4,461,985 $ 26.35 7.3 $ 186,299,331 Vested and expected to vest at June 30, 2021 4,455,816 $ 26.38 7.3 $ 185,891,183 Exercisable at June 30, 2021 2,670,402 $ 13.19 5.8 $ 145,918,708 The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option pricing model. The expected term of the Company’s stock options has been determined utilizing the “simplified” method as described in the SEC’s Staff Accounting Bulletin No. 107 relating to stock-based compensation. The simplified method was chosen because the Company has limited historical option exercise experience due to its short operating history. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for a period approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. Expected volatility is based on historical volatilities of similar entities within the Company’s industry which were commensurate with the Company’s expected term assumption. The weighted average grant date fair value of options granted was $48.74 per option for the six months ended June 30, 2021. As of June 30, 2021, there was $57.0 million of total unrecognized compensation cost related to non-vested stock options which is expected to be recognized over a weighted average period of 3.3 years. These amounts do not include 8,647 options outstanding as of June 30, 2021, which are performance-based and vest upon the achievement of certain corporate milestones. Stock‑based compensation will be measured and recorded if and when it is probable that the milestone will occur. Restricted Stock Units In 2020, the Company began granting RSUs covering an equal number of its shares of common stock to employees. The fair value of RSUs is determined on the date of the grant based on the market price of its shares of common stock as of that date. The fair value of the RSUs is recognized as an expense ratably over the vesting period of four years. As of June 30, 2021, total compensation cost not yet recognized related to unvested RSUs was $11.5 million, which is expected to be recognized over a weighted-average period of 3.4 years. The following table sets forth the RSU activity for the six months ended June 30, 2021: ​ Number of shares Weighted average grant date fair value Outstanding at December 31, 2020 136,067 $ 36.82 Granted 182,187 49.92 Vested (3,378 ) 47.54 Forfeited (5,750 ) 71.48 Outstanding at June 30, 2021 309,126 $ 43.78 Stock-based compensation expense recognized for the three and six months ended June 30, 2021 and 2020 was allocated as follows: ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2021 2020 2021 2020 Research and development $ 2,302,504 $ 1,037,530 $ 3,836,899 $ 1,671,905 General and administrative $ 3,153,738 3,110,495 5,350,440 4,609,650 Total $ 5,456,242 $ 4,148,025 $ 9,187,339 $ 6,281,555 Warrants The following table summarizes warrant activity for the six months ended June 30, 2021: Weighted average Number of warrants exercise price Outstanding at December 31, 2020 15,541 $ 80.43 Issued — — Exercised — — Outstanding at June 30, 2021 15,541 $ 80.43 Outstanding Warrants In connection with the first advance of the 2020 Term Loan, Hercules Capital Inc. received warrants to purchase an aggregate ten-day

License Agreements

License Agreements	6 Months Ended
	Jun. 30, 2021
Research And Development [Abstract]
License Agreements	Note 8. License Agreements Exclusive License Agreement with Pfizer In January 2020, the Company entered into an exclusive license agreement with Pfizer Inc. (“Pfizer”) for Pfizer’s clinical and nonclinical data, and intellectual property for reboxetine, the active pharmaceutical ingredient in AXS-12 which the Company is developing for the treatment of narcolepsy. The agreement also provides the Company exclusive rights to develop and commercialize esreboxetine, a new late-stage product candidate now referred to as AXS-14, in the U.S. for the treatment of fibromyalgia. Under the terms of the agreement, Pfizer received 82,019 shares of the Company’s common stock having a stated value of $8.0 million, based on the average closing price of the Company’s common stock for the ten prior trading days of $97.54, in consideration for the license and rights and also received an upfront cash payment of $3.0 million. The Company determined that the fair value of each share of common stock granted to Pfizer on the closing date of January 9, 2020 was $87.24, based on the closing price of the Company’s stock on that date. As a result, the fair value of the stock issued was $7.2 million and therefore, the total research and development expense recognized was $10.2 million related to the Pfizer license agreement during the six months ended June 30, 2020. Pfizer can also receive up to $323 million in regulatory and sales milestones, and tiered mid-single to low double-digit royalties on future sales. Pfizer will also have a right of first negotiation on any potential future strategic transactions involving AXS-12 and AXS-14. During the three months ended June 30, 2021, no milestone payments or royalties were paid to Pfizer by the Company. Exclusive License Agreements with Antecip In 2012, the Company entered into three exclusive license agreements with Antecip, in which it was granted exclusive licenses to develop, manufacture, and commercialize Antecip’s patents and applications related to the development of AXS-02, AXS-05, and AXS-04, a product candidate that is currently in early stage development, anywhere in the world for human therapeutic, veterinary, and diagnostic use. Pursuant to the agreements, the Company is required to use commercially reasonable efforts to develop, obtain regulatory approval for and commercialize AXS-02, AXS-05, and AXS-04. Under the terms of the agreements, the Company is required to pay to Antecip a royalty equal to 4.5% for AXS-02, 3.0% for AXS-05, and 1.5% for AXS-04, of net sales of products containing the licensed technology by the Company, its affiliates, or permitted sublicensees. These royalty payments are subject to reduction by an amount up to 50.0% of any required payments to third parties. Unless earlier terminated by a party for cause or by the Company for convenience, the agreements shall remain in effect on a product-by-product and country-by-country basis until the later to occur of (i) the applicable product is no longer covered by a valid claim in that country or (ii) 10 years from the first commercial sale of the applicable product in that country. Upon expiration of the agreements with respect to a product in a country, the Company’s license grant for that product in that country will become a fully paid-up, royalty-free, perpetual non-exclusive license. If Antecip terminates any of the agreements for cause, or if the Company exercises its right to terminate any of the agreements for convenience, the rights granted to the Company under such terminated agreement will revert to Antecip. To date, the Company has not been required to make any payments to Antecip under any of the license agreements. In connection with the 2020 Term Loan, the Company entered into a Direct Agreement with Antecip pursuant to which Antecip consented to the collateral assignment of the License Agreement to Hercules, among other things.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Significant Risks And Uncertainties	Significant Risks and Uncertainties The Company’s operations are subject to a number of factors that can affect its operating results and financial condition. Such factors include, but are not limited to: the results of clinical testing and trial activities of the Company’s product candidates; the Company’s ability to obtain regulatory approval to market its products, if approved; competition from products manufactured and sold or being developed by other companies; the price of, and demand for, the Company’s products, if approved; the Company’s ability to negotiate favorable licensing or other manufacturing and marketing agreements for its products, if approved; and the Company’s ability to raise additional financing. If the Company does not successfully commercialize any of its product candidates, it will be unable to generate recurring product revenue or achieve and maintain profitability.
Use of Estimates	Use of Estimates Management considers many factors in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. In preparing these financial statements, management used significant estimates in the following areas, among others: stock‑based compensation expense; the determination of the fair value of the warrants; the accounting for research and development costs; and the recoverability of the Company’s net deferred tax assets and related valuation allowance.
Foreign Currency Translation	Foreign Currency Translation Expenses denominated in foreign currency are translated into U.S. dollars at the exchange rate on the date the expense is incurred. Assets and liabilities of foreign operations are translated at period-end exchange rates. The effect of exchange rate fluctuations on translating foreign currency into U.S. dollars is included in the Statements of Operations and is not material to the Company’s financial statements.
Segment and Geographic Information	Segment and Geographic Information Operating segments are defined as components of an enterprise for which separate discrete information is available for evaluation by the chief operating decision maker or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business as one operating segment, which is the business of developing novel therapies for the management of CNS disorders.
Cash Equivalents	Cash Equivalents The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. The Company’s cash and cash equivalents includes holdings in checking and overnight sweep accounts. The Company’s cash equivalents, which are money market funds held in a sweep account, are measured at fair value on a recurring basis. As of June 30, 2021, the balance of cash and cash equivalents was $141.2 million, which approximates fair value and was determined based upon Level 1 inputs. The sweep account is valued using quoted market prices with no valuation adjustments applied. Accordingly, these securities are categorized as Level 1.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash. The Company maintains its cash at financial institutions, which at times, exceed federally insured limits. At June 30, 2021, the majority of the Company’s cash was held by one financial institution and the amount on deposit was in excess of Federal Deposit Insurance Corporation insurance limits. The Company has not recognized any losses from credit risks on such accounts since inception. The Company believes it is not exposed to significant credit risk on cash.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three‑level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1—Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly. Level 3—Inputs that are unobservable for the asset or liability. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s financial instruments are cash, accounts payable, accrued liabilities, and current and long-term debt. The carrying values for cash, accounts payable and accrued liabilities reported in the accompanying consolidated financial statements approximate their respective fair values due to their short-term maturities. The carrying value of debt on the Company’s balance sheet (see Note 6 – Loan and Security Agreement), is estimated to approximate its fair value as the interest rate approximates the market rate for loans with similar terms and risk characteristics.
Debt Issuance Costs	Debt Issuance Costs Debt issuance costs consist of costs incurred in obtaining long-term financing. These costs are classified on the consolidated balance sheet as a direct deduction from the carrying amount of the related debt liability. These expenses are deferred and amortized as part of interest expense in the consolidated statement of operations using the effective interest rate method over the term of the debt agreement.
Equipment	Equipment Equipment consists primarily of computer equipment and is recorded at cost. Equipment is depreciated on a straight‑line basis over its estimated useful life, which the Company estimates to be three years. When equipment is sold or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts and the resulting gain or loss is included in operating expenses.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses consist primarily of personnel costs for our research and development employees, costs incurred to third-party service providers for the conduct of research, preclinical and clinical studies, laboratory supplies, product license fees, consulting and other related expenses. We estimate research, preclinical and clinical study expenses based on services performed, pursuant to contracts with third-party research and development organizations that conduct and manage research, preclinical and clinical activities on our behalf. We estimate these expenses based on discussions with internal management personnel and external service providers as to the progress or stage of completion of services and the contracted fees to be paid for such services. If the actual timing of the performance of services or the level of effort varies from the original estimates, we will adjust the accrual accordingly. Payments associated with licensing agreements to acquire licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternative future use are expensed as incurred. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, operating losses, and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company estimates an annual effective tax rate of 0% for the year ending December 31, 2021 and has not recorded an income tax benefit for the six months ended June 30, 2021 and 2020 since it determined that a full valuation allowance is required against the Company’s deferred tax assets. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not to be sustained upon examination based on the technical merits of the position as well as consideration of the available facts and circumstances. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. As of June 30, 2021, the Company does not believe any material uncertain tax positions are present. In the event the Company determines that accrual of interest or penalties are necessary in the future, the amount will be presented as a component of income tax expense.
Stock Based Compensation	Stock-Based Compensation For stock options issued, the Company estimates the grant date fair value of each option using the Black‑Scholes option pricing model. The Black-Scholes model takes into account the expected volatility of the Company’s common stock, the risk-free interest rate, the estimated life of the option, the closing market price of the Company’s common stock and the exercise price. The estimates utilized in the Black-Scholes calculation involve inherent uncertainties and the application of management’s judgment. In addition, the Company recognizes expense for equity award forfeitures as they occur. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period, which is generally the vesting term. For restricted stock units (“RSUs”), the Company issues them in the form of Company common stock. The fair market value of these awards is based on the market closing price per share on the grant date. Prior to January 1, 2020, the Company only granted stock options. Beginning in 2020, for grants to employees, the Company granted a mix of stock options and RSUs. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period, which is generally the vesting term. For awards subject to performance-based vesting conditions, the Company recognizes stock-based compensation expense using the accelerated attribution method when it is probable that the performance condition will be achieved. The expense related to the stock-based compensation is recorded within the same financial statement line item as the grantee’s cash compensation. The Company’s policy upon exercise of stock options and RSUs is that shares will be issued as new shares drawing on the Company’s 2015 Omnibus Incentive Compensation Plan share pool that was adopted by the stockholders in November 2015.
Basic and Diluted Net Loss per Common Share	Basic and Diluted Net Loss per Common Share Basic net loss per share of common stock is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as warrants, stock options, and RSUs, which would result in the issuance of incremental shares of common stock. As the impact of these items is anti-dilutive during periods of net loss, there was no difference between basic and diluted net loss per share of common stock for the three and six months ended June 30, 2021 and 2020.
Leases	Leases The Company determines if an arrangement is a lease at contract inception. Operating lease assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. When evaluating whether a contract contains a lease, the Company considers whether (1) the contract explicitly or implicitly identifies assets that are contractually defined and (2) the Company obtains substantially all of the economic benefits from the use of that underlying asset and directs how and for what purpose the asset is used during the term of the contract. The Company’s lease agreement contains lease and non-lease components. Non-lease components primarily include payments for maintenance and utilities. The Company has applied the practical expedient to combine fixed payments for non-lease components with lease payments and account for them together as a single lease component, which increases the amount of lease assets and corresponding liabilities. Payments under the Company’s lease arrangement are primarily fixed, however variable payments, are expensed as incurred and not included in the operating lease asset and liability. Operating lease assets and liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The Company uses the implicit interest rate when readily determinable and uses the Company’s incremental borrowing rate when the implicit rate is not readily determinable based upon the information available at the commencement date in determining the present value of the lease payments. The Company’s operating leases are reflected in the right-of-use operating asset; operating lease liability, current portion; and operating lease liability, long-term portion in the Company’s consolidated balance sheets. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Short-term leases, defined as leases that have a lease term of 12 months or less at the commencement date, and do not include an option to extend the term or purchase the underlying asset that the Company is reasonably certain to exercise, are excluded from this treatment and are recognized on a straight-line basis over the term of the lease.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, enhances and simplifies various aspects of the income tax accounting guidance, including requirements such as tax basis step-up in goodwill obtained in a transaction that is not a business combination, ownership changes in investments, and interim-period accounting for enacted changes in tax law. ASU 2019-12 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2020. Early adoption is permitted, including adoption in an interim period. The Company adopted this standard on January 1, 2021, and the standard did not have a significant impact on its consolidated financial statements. In October 2020, the FASB issued ASU 2020-10, Codification Improvements, which clarifies various topics in the Accounting Standards Codification, including the addition of existing disclosure requirements to the relevant disclosure sections. The amendments in ASU 2020-10 do not change GAAP and, therefore, are not expected to result in a significant change in practice. ASU 2020-10 should be applied retrospectively to the beginning of the period that includes the adoption date. ASU 2020-10 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The Company adopted this standard on January 1, 2021, and the standard did not have a significant impact on its consolidated financial statements.

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	6 Months Ended
	Jun. 30, 2021
Accrued Liabilities And Other Liabilities [Abstract]
Schedule of Accrued Expenses	At June 30, 2021 and December 31, 2020 accrued expenses and other current liabilities consisted of the following: ​ June 30, 2021 December 31, 2020 Accrued research and development $ 2,195,033 $ 4,293,522 Accrued compensation 3,034,669 2,870,261 Accrued general and administrative 4,551,879 1,155,508 Accrued interest 381,250 393,958 Total $ 10,162,831 $ 8,713,249

Loan and Security Agreement (Ta

Loan and Security Agreement (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Schedule of Outstanding Debt and Unamortized Debt Discount Balances	The outstanding debt and unamortized debt discount balances are as follows: ​ June 30, 2021 December 31, 2020 Total Outstanding Debt $ 50,000,000 $ 50,000,000 Add: accreted liability of final payment fee 444,783 151,912 Less: unamortized debt discount, long-term (1,562,184 ) (1,830,064 ) Less: current portion of long-term debt — — Loan payable, long-term $ 48,882,599 $ 48,321,848
Schedule of Principal Payments	Scheduled Principal Payments on Outstanding Debt, as of June 30, 2021, are as follows: 2021 — 2022 — 2023 12,193,153 2024 19,761,468 2025 18,045,379 Total principal payments outstanding $ 50,000,000

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss per Common Share	The following table sets forth the computation of basic and diluted net loss per common share: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Basic and diluted net loss per common share: Net loss $ (32,284,209 ) $ (18,326,992 ) $ (61,544,179 ) $ (50,811,138 ) Weighted average common shares outstanding—basic and diluted 37,595,069 37,100,770 37,512,716 37,081,064 Net loss per common share—basic and diluted $ (0.86 ) $ (0.49 ) $ (1.64 ) $ (1.37 )
Schedule of Potentially Dilutive Securities	The following potentially dilutive securities outstanding at June 30, 2021 and 2020 have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive: June 30, 2021 2020 Stock options 4,461,985 3,979,607 Restricted stock units 309,126 150,143 Warrants 15,541 37,042 Total 4,786,652 4,166,792

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Schedule of Operating Lease Expense	For the three and six months ended June 30, 2021, the Company had the following operating lease expense: Three Months Ended June 30, Six Months Ended June 30, Statement of Operations Location 2021 2020 2021 2020 Operating lease expense General and administrative and Research and development $ 286,923 $ — $ 573,846 $ — Total operating lease expense $ 286,923 $ — $ 573,846 $ —
Schedule of Future Minimum Lease Payments of Operating Leases	Future minimum lease payments of the Company’s operating leases as of June 30, 2021 were as follows: 2021 $ 575,000 2022 630,000 2023 — 2024 — 2025 — Thereafter — Total lease payments 1,205,000 Less imputed interest (34,296 ) Present value of operating lease liabilities $ 1,170,704

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Summary of Stock Option Activity	The following table sets forth the stock option activity for the six months ended June 30, 2021: ​Number of shares ​Weighted average exercise price Weighted average contractual term ​Aggregate intrinsic value Outstanding at December 31, 2020 3,725,648 $ 16.36 Granted 955,213 66.05 Exercised (162,503 ) 17.67 Forfeited (55,727 ) 63.58 Expired (646 ) 87.76 Outstanding at June 30, 2021 4,461,985 $ 26.35 7.3 $ 186,299,331 Vested and expected to vest at June 30, 2021 4,455,816 $ 26.38 7.3 $ 185,891,183 Exercisable at June 30, 2021 2,670,402 $ 13.19 5.8 $ 145,918,708
Schedule of RSU Activity	The following table sets forth the RSU activity for the six months ended June 30, 2021: ​ Number of shares Weighted average grant date fair value Outstanding at December 31, 2020 136,067 $ 36.82 Granted 182,187 49.92 Vested (3,378 ) 47.54 Forfeited (5,750 ) 71.48 Outstanding at June 30, 2021 309,126 $ 43.78
Schedule of Stock-Based Compensation Expense Recognized	Stock-based compensation expense recognized for the three and six months ended June 30, 2021 and 2020 was allocated as follows: ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2021 2020 2021 2020 Research and development $ 2,302,504 $ 1,037,530 $ 3,836,899 $ 1,671,905 General and administrative $ 3,153,738 3,110,495 5,350,440 4,609,650 Total $ 5,456,242 $ 4,148,025 $ 9,187,339 $ 6,281,555
Schedule of Warrant Activity	The following table summarizes warrant activity for the six months ended June 30, 2021: Weighted average Number of warrants exercise price Outstanding at December 31, 2020 15,541 $ 80.43 Issued — — Exercised — — Outstanding at June 30, 2021 15,541 $ 80.43

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Details)	Jun. 30, 2021USD ($)product	Dec. 31, 2020USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of late-stage candidates in Company's product candidate portfolio | product	5
Accumulated deficit | $	$ 340,340,272	$ 278,796,093

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	6 Months Ended		12 Months Ended
	Jun. 30, 2021USD ($)segmentinstitution	Jun. 30, 2020USD ($)	Dec. 31, 2021
Segment and Geographic Information
Number of operating segments | segment	1
Cash Equivalents
Cash Equivalents	$ 141,200,000
Concentration of Credit Risk
Number of financial institutions that hold the Company's cash | institution	1
Equipment
Estimated useful life	3 years
Income Taxes
Income tax benefit	$ 0	$ 0
2019-12
Recent Accounting Pronouncements
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
2020-10
Recent Accounting Pronouncements
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
Forecast
Income Taxes
Effective tax rate			0.00%

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Accrued Liabilities And Other Liabilities [Abstract]
Accrued research and development	$ 2,195,033	$ 4,293,522
Accrued compensation	3,034,669	2,870,261
Accrued general and administrative	4,551,879	1,155,508
Accrued interest	381,250	393,958
Total	$ 10,162,831	$ 8,713,249

Loan and Security Agreement - A

Loan and Security Agreement - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2019
Line Of Credit Facility [Line Items]
Interest expense		$ 1,156,458	$ 379,167	$ 2,300,208	$ 758,334
Amortization of debt issuance costs		149,281	119,014	292,870	238,028
Amortization of debt discount				$ 560,752	356,664
Warrants
Line Of Credit Facility [Line Items]
Percentage of aggregate amount of loan				2.50%
Amortization of debt discount		$ 132,508	$ 59,998	$ 267,882	$ 118,636
Term Loan 2020
Line Of Credit Facility [Line Items]
First advance used to repay previous debt	$ 21,700,000
Base interest rate	9.15%
Cash pay interest rate	1.00%
Cash pay interest multiplier	1.15
Final payment fee	$ 2,910,000
Percentage of final payment fee	4.85%
Term Loan 2020 | Prime Rate
Line Of Credit Facility [Line Items]
Interest rate basis	5.90%
Term Loan 2020 | Prepayment Occurs Prior to First Anniversary of Closing Date
Line Of Credit Facility [Line Items]
Maximum loan amount	$ 225,000,000
Percentage of prepayment penalty	2.00%
Term Loan 2020 | Outstanding principle and advances under the loans agreement exceeds 55 million
Line Of Credit Facility [Line Items]
Minimum cash to be maintain as a first priority security interest	$ 15,000,000
Period of unpaid invoices amount maintain as security	180 days
Term Loan 2020 | Outstanding principle and advances under the loans agreement exceeds 55 million | Minimum
Line Of Credit Facility [Line Items]
Outstanding amount	$ 55,000,000
Term Loan 2020 | Outstanding principle and advances under the loans agreement exceeds 65 million
Line Of Credit Facility [Line Items]
Minimum amount of market capital to be maintained	$ 2,000,000,000
Minimum percentage of cash to be maintained as a security following market capitalization condition	65.00%
Minimum percentage of cash to be maintained as a security	100.00%
Term Loan 2020 | Outstanding principle and advances under the loans agreement exceeds 65 million | AXS-05 and AXS-07
Line Of Credit Facility [Line Items]
Minimum product revenue percent	60.00%
Term Loan 2020 | Outstanding principle and advances under the loans agreement exceeds 65 million | Minimum
Line Of Credit Facility [Line Items]
Outstanding amount	$ 65,000,000
Term Loan 2020 | Prepayment Occurs on or After First Anniversary and Prior to Second Anniversary of the Closing Date
Line Of Credit Facility [Line Items]
Percentage of prepayment penalty	1.50%
Term Loan 2020 | Prepayment Occurs on or After Second Anniversary and Prior to Third Anniversary of Closing Date
Line Of Credit Facility [Line Items]
Percentage of prepayment penalty	1.00%
Term loan 2020 tranche one
Line Of Credit Facility [Line Items]
Maximum loan amount	$ 60,000,000
Proceeds from debt	50,000,000
Remaining credit facility to be drawn	10,000,000
Term loan 2020 tranche two
Line Of Credit Facility [Line Items]
Maximum loan amount	$ 35,000,000
Period to achieve first milestone	181 days
Term loan 2020 tranche three
Line Of Credit Facility [Line Items]
Maximum loan amount	$ 20,000,000
Period to achieve second milestone	181 days
Term loan 2020 tranche four
Line Of Credit Facility [Line Items]
Maximum loan amount	$ 60,000,000
Term loan 2020 tranche five
Line Of Credit Facility [Line Items]
Maximum loan amount	$ 50,000,000
2019 Term Loan
Line Of Credit Facility [Line Items]
Maximum loan amount						$ 24,000,000

Loan and Security Agreement - S

Loan and Security Agreement - Schedule of Outstanding Debt and Unamortized Debt Discount Balances (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Total Outstanding Debt	$ 50,000,000	$ 50,000,000
Add: accreted liability of final payment fee	444,783	151,912
Less: unamortized debt discount, long-term	(1,562,184)	(1,830,064)
Loan payable, long-term	$ 48,882,599	$ 48,321,848

Loan and Security Agreement -_2

Loan and Security Agreement - Schedule of Principal Payments (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2023	$ 12,193,153
2024	19,761,468
2025	18,045,379
Total principal payments outstanding	$ 50,000,000	$ 50,000,000

Net Loss per Common Share - Com

Net Loss per Common Share - Computation of Basic and Diluted Net Loss per Common Share (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Basic and diluted net loss per common share:
Net loss	$ (32,284,209)	$ (29,259,970)	$ (18,326,992)	$ (32,484,146)	$ (61,544,179)	$ (50,811,138)
Weighted average common shares outstanding, basic and diluted	37,595,069		37,100,770		37,512,716	37,081,064
Net loss per common share, basic and diluted	$ (0.86)		$ (0.49)		$ (1.64)	$ (1.37)

Net Loss per Common Share - Pot

Net Loss per Common Share - Potentially Dilutive Securities Outstanding (Details) - shares	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	4,786,652	4,166,792
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	4,461,985	3,979,607
Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	309,126	150,143
Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	15,541	37,042

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Operating Lease Expense (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
Loss Contingencies [Line Items]
Total operating lease expense	$ 286,923	$ 573,846
General and Administrative and Research and Development
Loss Contingencies [Line Items]
Total operating lease expense	$ 286,923	$ 573,846

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments of Operating Leases (Details)	Jun. 30, 2021USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2021	$ 575,000
2022	630,000
Total lease payments	1,205,000
Less imputed interest	(34,296)
Present value of operating lease liabilities	$ 1,170,704

Commitments and Contingencies_3

Commitments and Contingencies - Additional Information (Details)	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Operating lease, remaining lease term	1 year 1 month 6 days
Operating lease, discount rate	6.00%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Dec. 05, 2019USD ($)	Dec. 31, 2019USD ($)$ / sharesshares	May 31, 2019USD ($)	Jun. 30, 2021USD ($)Voted$ / sharesshares	Jun. 30, 2020USD ($)shares	Dec. 31, 2020$ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, voting right per share | Vote				1
Weighted average grant date fair value | $ / shares				$ 48.74
Unrecognized compensation cost related to non-vested stock options expected to be recognized				$ 57,000,000
Expected vesting period for non-vested share-based compensation				3 years 3 months 18 days
Non-vested options outstanding | shares				8,647
Exercise price of warrants (in dollars per share) | $ / shares				$ 80.43		$ 80.43
Warrants | Term loan 2020 tranche one
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock to be issued if warrants are exercised (in shares) | shares				15,541
Exercise price of warrants (in dollars per share) | $ / shares				$ 80.43
Trading days | d				10
Term of warrants (in years)				7 years
Fair value				$ 900,000
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period				4 years
Compensation cost not yet recognized related to unvested RSUs				$ 11,500,000
Weighted average contractual term				3 years 4 months 24 days
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant | shares				4,572,808
Underwritten Public Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock, gross		$ 200,100,000
Shares issued | shares		2,300,000
Proceeds from issuance of common stock, net		$ 187,100,000
Share Price | $ / shares		$ 87
2019 Shelf Registration
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock, gross	$ 229,300,000
SVB Leerink
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, commission percentage			3.00%
Common stock sales agreement, shares unsold amount			$ 29,900,000
SVB Leerink | December 2019 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, commission percentage		3.00%
Proceeds from issuance of common stock, gross				$ 7,400,000	$ 12,400,000
Shares issued | shares				110,296	141,678
Proceeds from issuance of common stock, net				$ 7,200,000	$ 12,100,000
Maximum [Member] | SVB Leerink
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, authorized amount			$ 50,000,000
Maximum [Member] | SVB Leerink | December 2019 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, authorized amount		$ 80,000,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($)	6 Months Ended
	Jun. 30, 2021
Number of shares
Number of shares, Outstanding, beginning balance	3,725,648
Number of shares, Granted	955,213
Number of shares, Exercised	(162,503)
Number of shares, Forfeited	(55,727)
Number of shares, Expired	(646)
Number of shares, Outstanding, ending balance	4,461,985
Number of shares, Vested and expected to vest	4,455,816
Number of shares, Exercisable	2,670,402
Weighted average exercise price
Weighted average exercise price, Outstanding, beginning balance	$ 16.36
Weighted average exercise price, Granted	66.05
Weighted average exercise price, Exercised	17.67
Weighted average exercise price, Forfeited	63.58
Weighted average exercise price, Expired	87.76
Weighted average exercise price, Outstanding, ending balance	26.35
Weighted average exercise price, Vested and expected to vest	26.38
Weighted average exercise price, Exercisable	$ 13.19
Weighted average contractual term
Weighted average contractual term, Outstanding	7 years 3 months 18 days
Weighted average contractual term, Vested and expected to vest	7 years 3 months 18 days
Weighted average contractual term, Exercisable	5 years 9 months 18 days
Aggregate intrinsic value
Aggregate intrinsic value, Outstanding	$ 186,299,331
Aggregate intrinsic value, Vested and expected to vest	185,891,183
Aggregate intrinsic value, Exercisable	$ 145,918,708

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of RSU Activity (Details) - Restricted Stock Units	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Number of shares
Number of shares, Outstanding, beginning balance | shares	136,067
Number of shares, Granted | shares	182,187
Number of shares, Vested | shares	(3,378)
Number of shares, Forfeited | shares	(5,750)
Number of shares, Outstanding, ending balance | shares	309,126
Weighted average grant date fair value
Weighted average grant date fair value, Outstanding, beginning balance | $ / shares	$ 36.82
Weighted average grant date fair value, Granted | $ / shares	49.92
Weighted average grant date fair value, Vested | $ / shares	47.54
Weighted average grant date fair value, Forfeited | $ / shares	71.48
Weighted average grant date fair value, Outstanding, ending balance | $ / shares	$ 43.78

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Stock-Based Compensation Expense Recognized (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 5,456,242	$ 4,148,025	$ 9,187,339	$ 6,281,555
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	2,302,504	1,037,530	3,836,899	1,671,905
General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 3,153,738	$ 3,110,495	$ 5,350,440	$ 4,609,650

Stockholders' Equity - Schedu_3

Stockholders' Equity - Schedule of Warrant Activity (Details)	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Warrants And Rights Note Disclosure [Abstract]
Number of warrants outstanding beginning balance | shares	15,541
Number of warrants issued | shares	0
Number of warrants exercised | shares	0
Number of warrants outstanding ending balance | shares	15,541
Weighted average exercise price, Beginning balance | $ / shares	$ 80.43
Issued (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	0
Weighted average exercise price, Ending balance | $ / shares	$ 80.43

License Agreements - Additional

License Agreements - Additional Information (Details)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2020USD ($)$ / sharesshares	Jun. 30, 2021USD ($)shares	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)shares	Jun. 30, 2020USD ($)	Dec. 31, 2012item	Dec. 31, 2020USD ($)shares	Jan. 09, 2020USD ($)$ / shares
Research And Development Arrangement Contract To Perform For Others [Line Items]
Number of common shares | shares		37,648,948		37,648,948			37,374,088
Value of common stock		$ 3,765		$ 3,765			$ 3,737
Research and development expense recognized		14,503,326	$ 10,542,957	31,099,014	$ 38,064,357
License Agreement | Antecip
Research And Development Arrangement Contract To Perform For Others [Line Items]
Number of exclusive license agreements | item						3
License agreement royalty, maximum reduction percent as a result of required third party payments						50.00%
License agreement term, from first commercial sale						10 years
License Agreement | Antecip | AXS-02
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement royalty as a percent of net sales						4.50%
License Agreement | Antecip | AXS-05
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement royalty as a percent of net sales						3.00%
License Agreement | Antecip | AXS-04
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement royalty as a percent of net sales						1.50%
Pfizer Inc | License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Number of common shares | shares	82,019
Value of common stock	$ 8,000,000
Prior trading days	10 days
Share price | $ / shares	$ 97.54
Upfront cash payment	$ 3,000,000
Fair value share price | $ / shares								$ 87.24
Fair value of common stock								$ 7,200,000
Research and development expense recognized					$ 10,200,000
Future milestone payments		323,000,000		$ 323,000,000
Milestone payments or royalties		$ 0