Aldeyra Therapeutics (ALDX) 10-K 17 Mar 22 2021 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 15, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Trading Symbol	ALDX
Entity Registrant Name	ALDEYRA THERAPEUTICS, INC.
Entity Central Index Key	0001341235
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Emerging Growth Company	false
Entity Small Business	true
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		58,098,965
Entity Public Float			$ 648,685,384
Entity Tax Identification Number	20-1968197
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	Specified portions of the registrant’s proxy statement with respect to the registrant’s 2022 Annual Meeting of Stockholders, which is to be filed pursuant to Regulation 14A within 120 days after the end of the registrant’s fiscal year ended December 31, 2021 , are incorporated by reference into Part III of this Annual Report on Form 10-K
Entity Address, Address Line One	131 Hartwell Avenue
Entity Address, Address Line Two	Suite 320
Entity Address, City or Town	Lexington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02421
City Area Code	781
Local Phone Number	761-4904
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, $0.001 par value per share
Entity File Number	001-36332
Auditor Firm ID	243
Auditor Name	BDO USA, LLP
Auditor Location	Boston, Massachusetts

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 104,790,989	$ 52,858,311
Cash equivalent - reverse repurchase agreements	125,000,000	25,000,000
Marketable securities	0	0
Prepaid expenses and other current assets	2,961,781	5,200,957
Total current assets	232,752,770	83,059,268
Fixed assets, net	32,487	59,925
Right of use assets	351,863	233,310
Total assets	233,137,120	83,352,503
Current liabilities:
Accounts payable	1,019,702	381,638
Accrued expenses	10,523,353	8,134,765
Current portion of long-term debt	0	3,659,776
Current portion of operating lease liabilities	229,607	233,310
Total current liabilities	11,772,662	12,409,489
Operating lease liabilities, long-term	125,232	0
Long-term debt, net of current portion	15,503,703	11,434,456
Total liabilities	27,401,597	23,843,945
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred stock, $0.001 par value, 15,000,000 shares authorized, none issued and outstanding
Common stock, voting, $0.001 par value; 150,000,000 authorized and 58,081,215 and 38,667,491 shares issued and outstanding, respectively	58,081	38,667
Additional paid-in capital	500,369,444	296,385,619
Accumulated other comprehensive income	0	0
Accumulated deficit	(294,692,002)	(236,915,728)
Total stockholders’ equity	205,735,523	59,508,558
Total liabilities and stockholders’ equity	$ 233,137,120	$ 83,352,503

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred Stock, par value	$ 0.001	$ 0.001
Preferred Stock, shares authorized	15,000,000	15,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	58,081,215	38,667,491
Common stock, shares outstanding	58,081,215	38,667,491

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 44,936,532	$ 24,681,301
Acquired in-process research and development	0	1,754,265
General and administrative	11,283,004	9,985,454
Loss from operations	(56,219,536)	(36,421,020)
Other income (expense):
Interest income	185,363	292,224
Interest expense	(1,742,101)	(1,904,198)
Total other income (expense), net	(1,556,738)	(1,611,974)
Loss before income taxes	(57,776,274)	(38,032,994)
Income tax benefit	0	(479,265)
Net loss	$ (57,776,274)	$ (37,553,729)
Net loss per share - basic and diluted	$ (1.07)	$ (1.11)
Weighted average common shares outstanding - basic and diluted	54,042,103	33,965,955

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (57,776,274)	$ (37,553,729)
Other comprehensive loss:
Unrealized loss on marketable securities	0	(5,866)
Total other comprehensive loss	0	(5,866)
Comprehensive loss	$ (57,776,274)	$ (37,559,595)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Voting Stock [Member]	Common Voting Stock [Member]Helio Vision, Inc [Member]Founders [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Helio Vision, Inc [Member]Founders [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2019	$ 48,082,317	$ 28,657		$ 247,409,793		$ 5,866	$ (199,361,999)
Beginning Balance, Shares at Dec. 31, 2019		28,656,832
Stock-based compensation	7,083,810			7,083,810
Issuance of common stock, acquisition of Helio Vision, Inc.			$ 273		$ (273)
Issuance of common stock, acquisition of Helio Vision, Inc., Shares			273,616
Issuance of common stock, net of issuance costs	40,716,544	$ 9,352		40,707,192
Issuance of common stock, net of issuance costs, Shares		9,351,749
Issuance of common stock, exercise of stock options	1,058,516	$ 219		1,058,297
Issuance of common stock, exercise of stock options, Shares		219,244
Issuance of common stock, employee stock purchase plan	126,966	$ 30		126,936
Issuance of common stock, employee stock purchase plan, Shares		30,254
Issuance of common stock, vested restricted stock awards		$ 136		(136)
Issuance of common stock, vested restricted stock awards, shares		135,796
Other comprehensive income (loss)	(5,866)					$ (5,866)
Net loss	(37,553,729)						(37,553,729)
Ending Balance at Dec. 31, 2020	59,508,558	$ 38,667		296,385,619			(236,915,728)
Ending Balance, Shares at Dec. 31, 2020		38,667,491
Stock-based compensation	7,006,857			7,006,857
Issuance of common stock, acquisition of Helio Vision, Inc.		$ 142		(142)
Issuance of common stock, acquisition of Helio Vision, Inc., Shares		141,965
Issuance of common stock, net of issuance costs	189,811,611	$ 18,092		189,793,519
Issuance of common stock, net of issuance costs, Shares		18,091,947
Issuance of common stock, exercise of stock options	$ 4,623,251	$ 634		4,622,617
Issuance of common stock, exercise of stock options, Shares	634,214	634,214
Issuance of common stock, employee stock purchase plan	$ 61,529	$ 12		61,517
Issuance of common stock, employee stock purchase plan, Shares		12,092
Issuance of common stock, vested restricted stock awards		$ 287		(287)
Issuance of common stock, vested restricted stock awards, shares		286,944
Issuance of common stock in connection with Helio Vision, Inc. acquisition milestone	2,499,991	$ 247		2,499,744
Issuance of common stock in connection with Helio Vision, Inc. acquisition milestone, Shares		246,562
Net loss	(57,776,274)						(57,776,274)
Ending Balance at Dec. 31, 2021	$ 205,735,523	$ 58,081		$ 500,369,444			$ (294,692,002)
Ending Balance, Shares at Dec. 31, 2021		58,081,215

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (57,776,274)	$ (37,553,729)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development	0	1,754,265
Deferred taxes	0	(479,265)
Stock-based compensation	7,108,027	7,083,810
Non-cash interest expense	409,471	566,020
Net amortization of premium on debt securities available for sale	0	(91,231)
Depreciation and ammortization	264,180	56,221
Change in assets and liabilities:
Prepaid expenses and other current assets	2,239,176	(3,396,507)
Accounts payable	638,064	(426,664)
Accrued expenses and other liabilities	4,561,449	(5,006,375)
Net cash used in operating activities	(42,555,907)	(37,493,455)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of fixed assets	(7,806)
Purchases of marketable securities	0	(5,776,090)
Sales of marketable securities	0	34,800,000
Net cash (used in) provided by investing activities	(7,806)	29,023,910
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of issuance costs	189,811,611	40,716,544
Proceeds from exercise of stock options	4,623,251	1,058,516
Proceeds from employee stock purchase plan	61,529	126,966
Net cash provided by financing activities	194,496,391	41,902,026
NET INCREASE IN CASH AND CASH EQUIVALENTS	151,932,678	33,432,481
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	77,858,311	44,425,830
CASH AND CASH EQUIVALENTS, END OF PERIOD	229,790,989	77,858,311
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	1,337,083	1,387,750
SUPPLEMENTAL INFORMATION AND DISCLOSURES OF NONCASH ACTIVITIES:
Common stock issued in connection with Helio Vision, Inc. acquisition milestone	58,081	38,667
Helio Vision, Inc [Member]
SUPPLEMENTAL INFORMATION AND DISCLOSURES OF NONCASH ACTIVITIES:
Common stock issued in connection with Helio Vision, Inc. acquisition milestone	$ 2,499,991

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. NATURE OF BUSINESS Aldeyra Therapeutics, Inc. (Aldeyra, Company, we, us and our) was incorporated in the state of Delaware on August 13, 2004 as Neuron Systems, Inc. On December 20, 2012, the Company changed its name to Aldexa Therapeutics, Inc. and, on March 17, 2014, the Company changed its name to Aldeyra Therapeutics, Inc. Aldeyra, together with its wholly-owned subsidiaries, is developing and commercializing next-generation medicines to i mprove the lives of patients with immune-mediated diseases . The Company’s principal activities to date include raising capital and research and development activities

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation – The accompanying consolidated financial statements were prepared in conformity with accounting principles generally accepted in the United States of America (US GAAP). Risks and Uncertainties –The ongoing research and development activities will be subject to extensive regulation by numerous governmental authorities in the United States. Prior to marketing in the United States, any drug developed by the Company must undergo rigorous preclinical and clinical testing and an extensive regulatory approval process implemented by the United States Food and Drug Administration (FDA) under the Food, Drug and Cosmetic Act. The Company has limited experience in conducting and managing the preclinical and clinical testing necessary to obtain regulatory approval. There can be no assurance that the Company will not encounter problems in the clinical trials that will cause the Company or the FDA to delay or suspend clinical trials. The Company’s success will depend in part on its ability to obtain patents and product license rights, maintain trade secrets, and operate without infringing on the property rights of others, both in the United States and other countries. There can be no assurance that patents issued to or licensed by the Company will not be challenged, invalidated, circumvented, or that the rights granted thereunder will provide proprietary protection or competitive advantages to the Company. Based on its current operating plan, the Company believes that its cash and cash equivalents as of December 31, 2021, will be sufficient to fund the Company's currently projected operating expenses through the end of 2023, including potential new drug application (NDA) submissions; initial commercialization of reproxalap, if approved; and continued early and late-stage development of our product candidates in ocular and systemic immune-mediated diseases. As a result of the COVID-19 pandemic, clinical site availability, staffing, and patient recruitment have been negatively affected and the timelines to complete the Company’s clinical trials may be delayed. The Company’s assessment of its liquidity and capital resources includes an estimate of the financial impacts of these changes. The Company will need to secure additional funding in the future, from one or more equity or debt financings, collaborations, or other sources, in order to carry out all of the Company’s planned research and development activities and regulatory activities; commercialize product candidates; or conduct any substantial, additional development requirements requested by the Food and Drug Administration (FDA). Additional funding may not be available to the Company on acceptable terms, or at all. If the Company is unable to secure additional capital, it will be required to significantly decrease the amount of planned expenditures and may be required to cease operations. Curtailment of operations would cause significant delays in the Company’s efforts to develop and introduce its products to market, which is critical to the realization of its business plan and the future operations of the Company. Use of Estimates – The preparation of consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions, including fair value estimates for investments that affect the reported amounts of assets, liabilities, and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis. The most significant estimates in the Company’s financial statements include, but are not limited to, estimates related to clinical trial accruals, estimates related to deferred and accrued research and development costs, and accounting for income taxes and the related valuation allowance. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. Segment Information – Operating segments are defined as components of an enterprise about 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 in one segment, which is the identification and development of next-generation medicines to improve the lives of patients with immune-mediated diseases. Cash and Cash Equivalents – The Company classifies all highly liquid investments with original maturities of three months or less as cash equivalents and all highly liquid investments with original maturities of greater than three months but less than 12 months as current marketable securities. The Company has a policy of making investments only with commercial institutions that have at least an investment grade credit rating. The Company invests its cash primarily in reverse repurchase agreements (RRAs), government securities and obligations, and money market funds. RRAs are collateralized by deposits in the form of ‘Government Securities and Obligations’ for an amount not less than 102 % of their value. The Company does not record an asset or liability related to the collateral as the Company is not permitted to sell or repledge the associated collateral. The Company has a policy that the collateral has at least an A (or equivalent) credit rating. The Company utilizes a third-party custodian to manage the exchange of funds as well as the requirement that collateral received is maintained at 102% of the value of the RRAs on a daily basis. Marketable Securities – Marketable securities consist of government securities and obligations with original maturities of more than 90 days. Investments are classified as available-for-sale and are recorded on the balance sheet at fair value with unrealized gains or losses reported as a separate component of other comprehensive income/(loss). Management determines the appropriate classification of its investments at the time of purchase and re-evaluates such determination at each balance sheet date. Fair Value of Financial Instruments – Financial instruments including cash equivalents and accounts payable are carried in the financial statements at amounts that approximate their fair value based on the short maturities of those instruments. Marketable securities are carried at fair value and are more fully described in Note 6. The carrying amount of the Company’s credit facility with Hercules Capital, Inc. approximates fair value since the effective interest rate approximates market rates currently available to the Company. Concentration of Credit Risk – Financial instruments that potentially subject the Company to significant concentrations of credit risk principally consist of cash, cash equivalents and marketable securities, if any. The Company places its cash and cash equivalents and marketable securities with financial institutions which management believes have high credit ratings. As part of its cash and investment management processes, the Company performs periodic evaluations of the credit standing of the financial institutions with whom it maintains deposits. Intellectual Property – The legal and professional costs incurred by the Company to acquire its patent rights are expensed as incurred and included in general and administrative expenses. At December 31, 2021 and 2020, the Company has determined that these expenses have not met the criteria to be capitalized since the future benefits to be derived from the patents is uncertain. Intellectual property related expenses for the years ended December 31, 2021 and 2020 were $ 1.3 million and $ 1.0 million, respectively. Income Taxes – The Company follows the provisions of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 740, Income Taxes (ASC 740) , in reporting deferred income taxes. ASC 740 requires a company to recognize deferred tax liabilities and assets for expected future income tax consequences of events that have been recognized in the Company’s financial statements. Under this method, deferred tax assets and liabilities are determined based on temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in the years in which the temporary differences are expected to reverse. Valuation allowances are provided if based on the weight of available evidence, it is more likely than not that some or all the deferred tax assets will not be realized. The Company accounts for uncertain tax positions pursuant to ASC 740 which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes. Management is not aware of any uncertain tax positions. Research and Development Costs – Research and development (R&D) costs are charged to expense as incurred and relate to salaries, employee benefits, stock-based compensation related to employees, consulting services, other operating costs and expenses associated with preclinical and clinical trial activities. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses. Accrued liabilities are recorded related to those expenses for which vendors have not yet billed us with respect to services provided and/or materials that we have received. Preclinical and clinical trial expenses relate to third-party services, subject-related fees at the sites where the Company’s clinical trials are being conducted, laboratory costs, analysis costs, toxicology studies and investigator fees. Costs associated with these expenses are generally payable on the passage of time or when certain milestones are achieved. Expense is recorded during the period incurred or in the period in which a milestone is achieved. In order to ensure that the Company has adequately provided for preclinical and clinical expenses during the proper period, the Company maintains an accrual to cover these expenses. These accruals are assessed on a quarterly basis and are based on such assumptions as expected total cost, the number of subjects and clinical trial sites and length of the study. Actual results may differ from these estimates and could have a material impact on the Company’s reported results. The Company’s historical accrual estimates have not been materially different from actual costs. In-process research and development – Assets purchased in an asset acquisition transaction are expensed as in-process research and development (IPR&D) unless the assets acquired are deemed to have an alternative future use, provided that the acquired asset did not also include processes or activities that would constitute a “business” as defined under GAAP, the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, has no established alternative future use. Acquired IPR&D payments are immediately expensed in the period in which they are incurred and include upfront payments, as well as transaction fees and subsequent pre-commercial milestone payments. Research and development costs incurred after the acquisition are expensed as incurred. Stock-Based Compensation – Stock-based payments are accounted for in accordance with the provisions of ASC 718, Compensation – Stock Compensation . For options, the fair value of stock-based payments is estimated, on the date of grant, using the Black-Scholes option pricing model. For restricted stock, fair value is based on the fair value of the stock on the date of grant. The resulting fair value for restricted stock and options expected to vest is recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the applicable restricted stock or option. The Company records the effect of forfeitures and cancellations when they occur. Comprehensive Loss – Comprehensive loss is defined as the change in equity during a period from transactions and other events and/or circumstances from non-owner sources. For December 31, 2021, comprehensive loss is equal to the Company’s net loss of $ 57.8 million. For December 31, 2020, comprehensive loss is equal to the Company's net loss of $ 37.6 million and a realized loss on marketable securities of $ 5.9 thousand . Net Loss Per Share – The Company computes net loss per share in accordance with the two-class method. Under the two-class method, net loss is allocated between common stock and other participating securities based on their participation rights. The Company has determined that the nonvested shares issued to the Helio founders represents a participating security and as such the nonvested shares are excluded from basic earnings per share. Net losses are not allocated to the nonvested stockholders for computing net loss per share under the two-class method because nonvested stockholders do not have contractual obligations to share in the losses of the Company. Basic earnings per share is calculated by dividing net loss allocable to common stockholders by the weighted average number of common stock outstanding. Diluted net loss per share is computed using the more dilutive of (a) the two-class method, or (b) treasury stock method, as applicable, to the potentially dilutive instruments. The weighted-average number of common shares outstanding gives effect to all potentially dilutive common equivalent shares, including outstanding stock options and restricted stock, warrants, and nonvested shares. Recent Accounting Pronouncements – In June 2016, the FASB issued (ASU) No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 requires that credit losses be reported as an allowance using an expected losses model, representing the entity’s current estimate of credit losses expected to be incurred. The accounting guidance currently in effect is based on an incurred loss model. For available-for-sale debt securities with unrealized losses, this standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. The amendments under ASU 2016-13 are effective for interim and annual fiscal periods beginning after December 15, 2022. The Company is continuing to evaluate the impact of ASU 2016-13 but does not expect the adoption of this ASU to have a material impact on its consolidated financial statements.

Helio vision acquisition

Helio vision acquisition	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Helio vision acquisition	3. HELIO VISION ACQUISITION On January 28, 2019 (Closing Date), the Company acquired Helio Vision, Inc. (Helio). As a result of the acquisition, the Company initially issued an aggregate of 1,160,444 shares of common stock to the former securityholders and an advisor of Helio. The founders of Helio were issued 568,627 shares and non-founders were issued 591,817 shares. The Helio founders’ shares are subject to vesting based on continued service to the Company over three years from the Closing Date of which 98 % are vested as of December 31, 2021 . The Company recognizes the expense associated with the founders’ restricted shares as compensation expense on a straight-line basis as the shares vest over the three-year period. For the year ended December 31, 2021 and 2020, the Company recorded $ 1.2 million and $ 1.3 million of research and development compensation expense, respectively, for the founders’ restricted shares. In January 2021, pursuant to the terms of the acquisition agreement, the Company issued 246,562 shares of its common stock to the former securityholders of Helio (January Shares). In addition, the Company, subject to the conditions of the acquisition agreement, is contingently obligated to make additional payments to the former securityholders of Helio as follows:(a) $ 10.0 million of common stock following approval by the FDA of a new drug approval application for the prevention and/or treatment of proliferative vitreoretinopathy or a substantially similar label prior to the 10th anniversary of the Closing Date; and (b) $ 2.5 million of common stock following FDA approval of a new drug application for an indication (other than proliferative vitreoretinopathy) prior to the 12th anniversary of the Closing Date (the shares of common stock issuable pursuant to the preceding clauses (a) and (b) are referred to herein as the Milestone Shares), provided that in no event shall the Company be obligated to issue more than an aggregate of 5,248,885 shares of common stock. Additionally, in the event of certain change of control or divestitures by the Company, certain former convertible noteholders of Helio will be entitled to a tax gross-up payment in an amount not to exceed $ 1.0 million. The Company determined that liability accounting is not required for the Milestone Shares under FASB ASC Topic 480, Distinguishing Liabilities from Equity (ASC 480). The Company also determined that the Milestone Shares meet the scope exception as a derivative under FASB ASC Topic 815, Derivatives and Hedging (ASC 815), from inception of the Milestone Shares through December 31, 2021. Accordingly, the Milestone Shares are evaluated under FASB ASC Topic 450, Contingencies (ASC 450) and the Company will record a liability related to the Milestone Shares if the milestones are achieved, and the obligation to make additional payment(s) becomes probable. At that time, the Company will record the cost of the Milestone Shares issued to the founders as compensation expense and to the Helio non-founders as IPR&D expense if there is no alternative future use. At December 31, 2020, the issuance of the January Shares was considered probable and $ 2.5 million was accrued as contingent consideration payable in stock and the Company recorded $ 1.8 million to IPR&D (Milestone IPR&D), which included a $ 0.5 million income tax benefit, and $ 1.2 million of compensation expense related to these January Shares, which amounted to 246,562 shares and were issued during the quarter ended March 31, 2021. No other milestones related to the remaining Milestone Shares are probable of being achieved as of December 31, 2021 .

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	4. NET LOSS PER SHARE For the years ended December 31, 2021 and 2020, diluted weighted-average common shares outstanding is equal to basic weighted-average common shares due to the Company’s net loss position. The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted-average shares outstanding, because such securities had an antidilutive impact: Years ended December 31, 2021 2020 Options to purchase common stock 4,622,870 4,608,311 Nonvested restricted stock units 501,255 927,189 Nonvested founder shares (1) 10,891 152,856 Total of common stock equivalents 5,135,016 5,688,356 (1) Represents 10,891 and 152,856 shares of common stock that are issued and outstanding but were subject to vesting based on service requirements at December 31, 2021 and 2020 , respectively, and are not included in stockholders’ equity.

Cash, Cash Equivalents and Mark

Cash, Cash Equivalents and Marketable Securities	12 Months Ended
	Dec. 31, 2021
Cash And Cash Equivalents [Abstract]
Schedule of Cash, and Cash Equivalents	5. CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES At December 31, 2021, cash and cash equivalents were comprised of: Carrying Unrecognized Unrecognized Estimated Fair Cash and Cash Cash $ 100,364,523 $ — $ — $ 100,364,523 $ 100,364,523 Money market funds 4,426,466 — — 4,426,466 4,426,466 Reverse repurchase agreements 125,000,000 — — 125,000,000 125,000,000 Total cash and cash equivalents $ 229,790,989 $ — $ — $ 229,790,989 $ 229,790,989 At December 31, 2020, cash and cash equivalents were comprised of: Carrying Unrecognized Unrecognized Estimated Fair Cash and Cash Cash $ 23,494,920 $ — $ — $ 23,494,920 $ 23,494,920 Money market funds 29,363,391 — — 29,363,391 29,363,391 Reverse repurchase agreements 25,000,000 — — 25,000,000 25,000,000 Total cash and cash equivalents $ 77,858,311 $ — $ — $ 77,858,311 $ 77,858,311 There were no marketable securities held at December 31, 2021 or December 31, 2020 .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. FAIR VALUE MEASUREMENTS 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 on the measurement date. Valuation techniques used to measure fair value are performed in a manner to maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820, Fair Value Measurements , establishes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value, which are the following: Level 1 – Quoted prices in active markets that are accessible at the market date for identical unrestricted assets or liabilities. Level 2 – Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs for which all significant inputs are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The following table presents information about the Company’s assets measured at fair value at December 31, 2021 and December 31, 2020: December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Money market funds (a) $ 4,426,466 $ — $ — $ 4,426,466 Reverse repurchase agreements (b) — 125,000,000 — 125,000,000 Total assets at fair value $ 4,426,466 $ 125,000,000 $ — $ 129,426,466 December 31, 2020 Level 1 Level 2 Level 3 Total Assets: Money market funds (a) $ 29,363,391 $ — $ — $ 29,363,391 Reverse repurchase agreements (b) — 25,000,000 — 25,000,000 Total assets at fair value $ 29,363,391 $ 25,000,000 $ — $ 54,363,391 (a) Money market funds included in cash and cash equivalents in the consolidated balance sheets, are valued at quoted market prices in active markets. (b) Reverse repurchase agreements and U.S. government agency securities, if any, are recorded at fair market values, which are determined based on the most recent observable inputs for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable.

Prepaid expenses and other curr

Prepaid expenses and other current assets	12 Months Ended
	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Prepaid Expenses and Other Current Assets	7. PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets at December 31, 2021 and 2020 were: December 31, December 31, 2021 2020 Deferred research and development expenses $ 2,404,145 $ 4,793,794 Miscellaneous prepaid expenses and other current assets 557,636 407,163 Total prepaid expenses and other current assets $ 2,961,781 $ 5,200,957

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued Expenses	ACCRUED EXPENSES Accrued expenses at December 31, 2021 and 2020 were: December 31, December 31, 2021 2020 Accrued compensation $ 1,512,885 $ 1,323,138 Contingent consideration payable in stock — 2,500,000 Accrued research and development expenses 8,415,560 3,944,094 Accrued general and administrative expenses 594,908 367,533 Total accrued expenses $ 10,523,353 $ 8,134,765

Credit Facility

Credit Facility	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Credit Facility	9. CREDIT FACILITY The Company’s long-term debt obligation consists of amounts the Company is obligated to repay under its credit facility with Hercules Capital, Inc. (Hercules). In March 2019, the Company entered into a Loan and Security Agreement with Hercules and several banks and other financial institutions or entities, from time-to-time parties thereto (collectively, referred to as Lender), providing for a term loan of up to $ 60.0 million, subject to the satisfaction of certain conditions contained therein, that is secured by a lien covering all of the Company’s assets, other than the Company’s intellectual property (Loan and Security Agreement or the Hercules Credit Facility). The Loan and Security Agreement provided for (i) an initial term loan advance of up to $ 5.0 million at the Company’s option, which expired unutilized on April 15, 2019; (ii) three additional term loan advances of up to $ 15.0 million each, at the Company’s option, available to the Company upon the occurrence of certain funding conditions prior to September 30, 2019 (2019 Tranche), March 31, 2020 (2020 Tranche), and March 31, 2021 (2021 Tranche); and (iii) a final additional term loan advance (Fourth Loan Tranche) of up to $ 10.0 million prior to December 31, 2021, at the Company’s option, subject to approval by the Lender’s investment committee. The 2019 Tranche was drawn down in full by the Company in September 2019 and the 2020 Tranche and 2021 Tranche expired unutilized prior to the Company satisfying the funding conditions for such tranche. On April 20, 2021, the Company entered into the First Amendment (First Amendment) to the Loan and Security Agreement with Hercules. The First Amendment, among other things, (i) increased the Fourth Loan Tranche from $ 10.0 million to $ 20.0 million and extended the deadline for drawing down the Fourth Loan Tranche to July 1, 2022; (ii) lowered the variable per annum rate of interest on borrowings under the Loan and Security Agreement from the greater of (a) 9.10 % and (b) the prime rate (as reported in the Wall Street Journal or any successor publication thereto) plus 3.10 % to the greater of (x) the Prime Rate (as defined therein) plus 3.10% or (y) 8.60%; (iii) extended the expiration of the period in which interest-only payments on borrowings under the Loan and Security Agreement are required from May 1, 2021 to July 1, 2022; and (iv) following the satisfaction of certain conditions in April 2021, further extended the expiration of the interest-only period and the deadline for drawing down the Fourth Loan Tranche to May 1, 2023 . Repayment of the aggregate outstanding principal balance of the term loan, in monthly installments, commences upon expiration of the interest-only period and continues through October 1, 2023 (Maturity Date). The First Amendment was determined to be a modification in accordance with FASB ASC Topic 470, Debt and did not result in extinguishment. Associated with this debt facility, the Company incurred a commitment charge of $ 25,000 , transaction costs of $ 273,186 , a fee of $ 375,000 upon closing, and is required to pay a fee (End of Term Charge) of 6.95 % multiplied by the aggregate amount of advances under the Loan and Security Agreement at maturity. The fees, transaction costs, and the End of Term Charge are amortized to interest expense from 2019 through the Maturity Date using the effective interest method. The effective interest rate was 10.8 % at December 31, 2021 . At the Company’s option, the Company may elect to prepay all, but not less than all, of the outstanding term loan by paying the entire principal balance and all accrued and unpaid interest thereon plus all fees and other amounts due under the Loan and Security Agreement, including a prepayment charge equal to 1.5 % of the principal amount being prepaid. Following the effective time of the First Amendment and as of December 31, 2021 , an aggregate of $ 35 million, subject to the terms and conditions of the Loan and Security Agreement, may be made available to the Company for borrowing, $ 15 million of which was funded prior to the date of the First Amendment. Long-term debt consisted of the following: December 31, December 31, 2021 2020 Term loan payable $ 15,000,000 $ 15,000,000 End of term charge 703,269 445,464 Unamortized debt issuance costs ( 199,566 ) ( 351,232 ) Less: current portion — ( 3,659,776 ) Total long-term debt $ 15,503,703 $ 11,434,456 Future principal payments, including the End of Term Charge, are as follows for the years ending December 31: 2022 $ — 2023 16,042,500 Total $ 16,042,500 The Loan and Security Agreement also contains certain events of default, representations, warranties and non-financial covenants of the Company. As of December 31, 2021, the Company was in material compliance with all covenants of the Hercules Credit Facility. In addition, subject to the terms of the Loan and Security Agreement, the Company granted the Lender the right to purchase up to an aggregate of $ 2.0 million of the Company’s equity securities, or instruments exercisable for or convertible into equity securities, sold to investors in financings upon the same terms and conditions afforded to such other investors.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders' Equity	10. STOCKHOLDERS’ EQUITY Common Stock Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors, subject to the prior rights of holders of all classes of stock outstanding. As of December 31, 2021, a total of 4,622,870 , 3,044,303 , and 1,233,557 , shares of common stock were reserved for issuance upon (i) the exercise of outstanding stock options, (ii) the issuance of stock awards under the Company’s Amended 2013 Plan, and (iii) the issuance of shares under the 2016 ESPP, respectively. 2018 Jefferies Sales Agreement In December 2018, the Company entered into an Open Market Sales Agreement SM (2018 Jefferies Sales Agreement) with Jefferies LLC (Jefferies), as sales agent, pursuant to which the Company could offer and sell, from time to time through Jefferies, shares of common stock providing for aggregate sales proceeds of up to $ 50.0 million. During the year ended December 31, 2020, the Company sold, at a volume-weighted average price of $ 4.62 , an aggregate of 9,351,749 shares of common stock and received $ 40.7 million after deducting commissions related to the 2018 Jefferies Sales Agreement and other offering costs. As of December 31, 2020, the Company had sold the maximum allowable amount and no further sales may be made under the 2018 Jefferies Sales Agreement. 2021 Jefferies Sales Agreement In March 2021, the Company entered into an Open Market Sales Agreement SM (2021 Jefferies Sales Agreement) with Jefferies, as sales agent, pursuant to which the Company may offer and sell, from time to time through Jefferies, shares of common stock providing for aggregate sales proceeds of up to $ 100.0 million. The Company has no obligation to sell any shares under the 2021 Jefferies Sales Agreement, and could at any time suspend solicitations and offers under the 2021 Jefferies Sales Agreement. No sales had been made pursuant to the 2021 Jefferies Sales Agreement as of December 31, 2021. Underwritten Public Offerings In January 2021, the Company sold 7.9 million shares of its common stock in an underwritten public offering at $ 9.50 per share, for an aggregate gross cash purchase price of $ 74.7 million or proceeds of $ 70.0 million after underwriters’ discount, commissions, and other offering expenses. In May and June 2021, the Company sold an aggregate of 10.2 million shares of its common stock at a public offering price of $ 12.50 per share, in an underwritten public offering, for an aggregate gross cash purchase price of $ 127.8 million or proceeds of $ 119.8 million after underwriters’ discount, commissions, and other offering expenses, which included the partial exercise of the underwriters' option to purchase additional shares.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	11. INCOME TAXES No current or deferred tax provision expenses for federal and state income taxes have been recorded as the Company has incurred losses since inception for tax purposes. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. In assessing the realizability of net deferred taxes in accordance with ASC 740 the Company considers whether it is more likely than not that some portion or all the deferred tax assets will not be realized. Based on the weight of available evidence, primarily the incurrence of net losses since inception, anticipated net losses in the near future, reversals of existing temporary differences and expiration of various federal and state attributes, the Company does not consider it more likely than not that some or all of the net deferred taxes will be realized. Accordingly, a 100 % valuation allowance has been applied against net deferred taxes. Effective January 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes (Topic 740), which did not have a material impact to the Company’s financial statements. As of December 31, 2021, the Company had federal and state income tax net operating loss (NOL) carryforwards of approximately $ 226.0 million and $ 219.0 million , respectively. Federal NOL carryforwards generated through December 31, 2017 and state NOL carryforwards will expire at various dates through 2041 . The federal NOL carryforwards generated during the year ended December 31, 2018 and thereafter will carryforward indefinitely. As of December 31, 2021, the Company had federal and state research and development tax credit carryforwards of approximately $ 6.9 million and $ 1.6 million , respectively, which will expire at various dates through 2041 . Additionally, as of December 31, 2021 , the Company had a federal orphan drug tax credit carryforward of approximately $ 1.0 million that expires in 2041 . The Coronavirus Aid, Relief and Economic Security (CARES) Act was enacted in the United States on March 27, 2020. CARES includes several income tax provisions such as NOL carryback and carryforward benefits and other tax deduction benefits. As noted previously, the Company’s U.S. deferred tax asset has a full valuation allowance, accordingly these NOL and other benefit provisions have no impact on the Company’s financial statements for the period ended December 31, 2021. Significant components of the Company’s deferred tax assets and liabilities at December 31, 2021 and 2020 are as follows: Years ended December 31, 2021 2020 Deferred Tax Assets Federal & state NOL carryforward $ 61,308,787 $ 48,273,248 Federal & state R&D credit 9,200,758 6,375,229 Intangibles – net 78,378 78,378 Accounts payable and accrued 2,301,117 192,200 Stock options 3,906,501 3,762,247 Other items 127,791 94,020 Gross deferred tax assets 76,923,332 58,775,322 Valuation allowance ( 76,827,203 ) ( 58,711,582 ) Deferred tax assets, net $ 96,129 $ 63,740 Deferred Tax Liabilities Right of use asset ( 96,129 ) ( 63,740 ) TOTAL $ — $ — The change in valuation allowance of $ 18.1 million from December 31, 2020 to December 31, 2021 was primarily the result of an increase in net operating losses and tax credits. The components of the income tax benefit for the years ended December 31, 2021 and 2020, are as follows: Years ended December 31, 2021 2020 Deferred Taxes Federal $ — $ ( 338,924 ) State — ( 140,341 ) Total income tax benefit $ — $ ( 479,265 ) Future changes in federal and state tax laws pertaining to net operating loss carryforwards may also cause limitations or restrictions from us claiming such net operating losses. If the net operating loss carryforwards become unavailable to us or are fully utilized, our future taxable income will not be shielded from federal and state income taxation absent certain U.S. federal and state tax credits, and the funds otherwise available for general corporate purposes would be reduced. Under Section 382 of the Internal Revenue Code of 1986, as amended, a corporation that undergoes an “ownership change” is subject to limitations on its ability to utilize its pre-change NOLs and certain other tax assets to offset future taxable income. In general, an ownership change occurs if the aggregate stock ownership of certain stockholders increases by more than 50 percentage points over such stockholders’ lowest percentage ownership during the testing period (generally three years). Transactions involving the Company’s common stock within the testing period, even those outside the Company’s control such as purchases or sales by investors, could result in an ownership change. A limitation on the Company’s ability to utilize some or all its NOLs or credits could have a material adverse effect on the Company’s results of operations and cash flows. Company believes, prior to December 31, 2020 that the three ownership changes occurred since inception, and that a fourth ownership change was triggered during the year ended December 31, 2021. Management believes that its aggregate Section 382 limitation (including the additional limitation for recognized "built-in gains") is sufficient so that no current impairment of its pre-ownership change tax attributes is required. Any future ownership changes, including those resulting from any recent or future financing activities, may cause our existing tax attributes to have additional limitations. As of December 31, 2021, the Company is subject to tax in the U.S. (Federal and Massachusetts). The Company is open to examination for the tax years ended December 31, 2021, 2020, 2019 and 2018. In addition, any loss years remain open to the extent that losses are available for carryover to future years. A reconciliation of the federal statutory tax rate of 21 % to the Company’s effective income tax rates are as follows: Years ended December 31, 2021 2020 Statutory tax rate 21.00 % 21.00 % State taxes, net of federal benefits 6.65 % 5.06 % Federal research and development credits 4.29 % 3.28 % Change in valuation allowance ( 31.35 ) % ( 22.76 ) % Stock-based compensation ( 0.73 ) % ( 5.85 ) % Other 0.14 % 0.55 % Effective tax rate ( 0.00 ) % 1.28 %

Stock Incentive Plan

Stock Incentive Plan	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Incentive Plan	12. STOCK INCENTIVE PLAN The Company approved the 2010 Employee, Director and Consultant Equity Incentive Plan (2010 Plan) in September 2010 to replace the 2004 Employee, Director and Consultant Equity Incentive Plan. The 2010 Plan provided for the granting of stock options and restricted stock awards. The 2010 Plan terminated upon the Company’s initial public offering in May 2014. However, grants made under the 2010 Plan are still governed by that plan. As of December 31, 2021, options to purchase 398,547 shares of common stock at a weighted average exercise price of $ 1.52 per share remained outstanding under the 2010 Plan. The Company approved the 2013 Equity Incentive Plan in October 2013. The 2013 Equity Incentive Plan became effective immediately on adoption. The 2013 Equity Incentive Plan was amended in June 2016 and June 2018, (Amended 2013 Plan). The Amended 2013 Plan provides for the granting of stock options, restricted stock, stock appreciation rights, stock units, and performance cash awards to certain employees, members of the board of directors and consultants of the Company. On January 1 of each year the aggregate number of common shares that may be issued under the Amended 2013 Plan shall automatically increase by a number of shares equal to the lower of (a) 6 % of the total number of shares of common stock outstanding on the last calendar day of the prior fiscal year, or (b) a number of shares of common stock determined by the Company’s board of directors. As of December 31, 2021, options to purchase 4,224,323 shares of common stock at a weighted average exercise price of $ 7.23 per share and 501,255 shares of common stock underlying restricted stock units remained outstanding under the Amended 2013 Plan. As of December 31, 2021, there were 3,044,303 shares of common stock available for grant under the Amended 2013 Plan. As of January 1, 2022, the number of shares of common stock that may be issued under the Amended 2013 Plan was automatically increased by 3,485,526 shares, increasing the number of shares of common stock available for issuance under the Amended 2013 Plan to 6,529,829 . In 2019 and 2020, the Company granted performance cash awards. The performance cash awards vest in four annual installments from the date of grant and entitle the employees to receive a cash payment, on the earlier of (i) four years from the date of grant or (ii) a change of control, equal in value to the amount by which the then value of the Company’s common stock exceeds the base value. As of December 31, 2021 , $ 0.4 million was accrued as compensation expense for vested performance cash awards. The Company recognizes stock-based compensation expense over the requisite service period. The Company’s share-based awards are accounted for as equity instruments. The amounts included in the consolidated statements of operations relating to stock-based compensation associated with the two equity incentive plans, performance cash awards, and Helio founders’ shares are as follows: Years ended December 31, 2021 2020 Research and development expenses $ 3,562,181 $ 3,798,141 General and administrative expenses 3,545,846 3,285,669 Total stock-based compensation expense $ 7,108,027 $ 7,083,810 Stock Options Terms of stock option agreements, including vesting requirements, are determined by the board of directors or its compensation committee, subject to the provisions of the respective plan from which they were granted. Options granted by the Company typically vest over a four-year period. The options are subject to acceleration of vesting in the event of certain change of control transactions. The options may be granted for a term of up to ten years from the date of grant. The exercise price for options granted under the Amended 2013 Plan must be at a price no less than 100 % of the fair market value of a common share on the date of grant. The following table summarizes option activity under the incentive plans for the year ended December 31, 2021: Number of Weighted Weighted Aggregate Outstanding at December 31, 2020 4,608,311 $ 5.73 $ 7,492,474 Granted 965,169 11.40 - Cancelled/Forfeited ( 316,396 ) 5.23 2,217,529 Exercised ( 634,214 ) 7.29 2,450,104 Outstanding at December 31, 2021 4,622,870 $ 6.73 6.71 $ 1,268,089 Exercisable at December 31, 2021 3,134,196 $ 5.90 5.79 $ 1,150,723 (a) The aggregate intrinsic value in this table was calculated on the positive difference, if any, between the closing price per share of the Company’s common stock on December 31, 2021 of $ 4.00 and the per share exercise price of the underlying options. The Company records stock-based compensation related to stock options granted at fair value. During the years ended December 31, 2021 and 2020, the Company used the Black-Scholes option-pricing model to estimate the fair value of stock option grants and to determine the related compensation expense. The assumptions used in calculating the fair value of stock-based payment awards represent management’s best estimates. The weighted-average fair value of options granted was $ 7.95 and $ 2.57 for the years ended December 31, 2021 and 2020 , respectively. The assumptions used in determining fair value of the employee stock options for the years ended December 31, 2021 and 2020, are as follows: December 31, December 31, Expected dividend yield 0 % 0 % Anticipated volatility 81.73 % - 83.50 % 75.83 % - 82.83 % Stock price $ 8.33 - $ 12.97 $ 2.98 - $ 6.77 Exercise price $ 8.33 - $ 12.97 $ 2.98 - $ 6.77 Expected life (years) 5.50 - 6.08 5.50 - 6.25 Risk free interest rate 0.88 % - 1.67 % 0.39 % - 1.71 % The dividend yield of zero is based on the fact that the Company has never paid cash dividends and have no present intention to pay cash dividends. Expected volatility is estimated using the historical volatility of the Company. The Company has estimated the expected life of its employee stock options using the “simplified” method, whereby, the expected life equals the average of the vesting term and the original contractual term of the option for service-based awards since the Company doesn’t have sufficient historical or implied data of its own. The risk-free interest rates for periods within the expected life of the option are based on the yields of zero-coupon United States Treasury securities. At December 31, 2021, there is approximately $ 7.5 million of unrecognized compensation cost relating to stock options outstanding, which the Company expects to recognize over a weighted average period of 2.50 years. Total unrecognized compensation cost will be adjusted for future forfeitures, if necessary. Restricted Stock Units Terms of restricted stock unit (RSUs) agreements, including vesting requirements, are determined by the board of directors or its compensation committee, subject to the provisions of the Amended 2013 Plan. RSUs granted by the Company typically vest over a four year period. In the event that the employees’ employment with the Company terminates any unvested shares are forfeited and revert to the Company. RSUs are not included in issued and outstanding common stock until the shares are vested and released. The table below summarizes activity relating to RSUs for the year ended December 31, 2021 : Number Outstanding at December 31, 2020 927,189 Granted 46,619 Cancelled/Forfeited ( 185,610 ) Vested/released ( 286,943 ) Outstanding at December 31, 2021 501,255 The weighted-average fair value of RSUs granted was $ 11.71 and $ 3.78 per share for the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021, the outstanding RSUs had unamortized stock-based compensation of $ 1.7 million with a weighted-average remaining recognition period of 1.91 years and an aggregate intrinsic value of $ 3.0 million . Employee Stock Purchase Plan In March 2016, the Company’s board of directors approved the 2016 Employee Stock Purchase Plan (2016 ESPP), which became effective in June 2016 following the approval of the Company’s stockholders. The 2016 ESPP initially authorized the issuance of up to a total of 414,639 shares of the Company’s common stock to participating employees. The number of shares reserved for issuance under the 2016 ESPP automatically increases on the first business day of each fiscal year, commencing in 2017, by a number equal to the lower of (i) 1 % of the shares of common stock outstanding on the last business day of the prior fiscal year; or (ii) the number of shares determined by the Company’s Board of Directors. Unless otherwise determined by the administrator of the 2016 ESPP, two offering periods of six months’ duration will begin each year on January 1 and July 1. Participating employees purchase stock under the 2016 ESPP at a price equal to the lower of 85 % of the closing price on the applicable offering commencement date or 85 % of the closing price on the applicable offering termination date. The fair value of the purchase rights granted under this plan was estimated on the date of grant using the Black-Scholes option-pricing model using assumptions as shown below: December 31, December 31, Expected dividend yield 0 % 0 % Anticipated volatility 81.76 % - 82.87 % 80.66 % - 82.61 % Stock price $ 6.53 - $ 11.31 $ 4.17 - $ 5.96 Exercise price $ 6.53 - $ 11.31 $ 4.17 - $ 5.96 Expected life (years) 0.50 0.50 Risk free interest rate 0.05 % - 0.09 % 0.17 % - 1.57 % At December 31, 2021, the Company has 1,233,557 shares available for issuance under the 2016 ESPP. A summary of the weighted-average grant-date fair value, shares issued and total stock-based compensation expense recognized related to the 2016 ESPP for the years ended December 31, 2021 and 2020 are as follows: December 31, December 31, Weighted-average grant-date fair value $ 2.98 $ 2.13 Total shares issued 12,092 30,254 Total stock-based compensation expense $ 45,190 $ 34,224

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. COMMITMENTS AND CONTINGENCIES Guarantees and Indemnifications , the Company had not experienced any losses related to these indemnification obligations and no material claims were outstanding. The Company does not expect significant claims related to these indemnification obligations, and consequently, concluded that the fair value of these obligations is negligible, and no related reserves were established. In-License Agreements Madrigal Agreement The Company is developing ADX-1612 pursuant to a License Agreement with Madrigal Pharmaceuticals, Inc. (Madrigal), entered into on December 26, 2016 (Madrigal Agreement). Pursuant to the Madrigal Agreement, the Company obtained an exclusive, worldwide license from Madrigal under certain patents and patent applications, and other licenses to intellectual property, to develop and commercialize Hsp90 inhibitors, including ADX-1612, (collectively, Madrigal Agreement Products). The Company has agreed to use its commercially reasonable efforts to develop Madrigal Agreement Products. In consideration for the rights licensed under the Madrigal Agreement, the Company paid Madrigal an upfront license fee of $ 250,000 and are obligated to make future regulatory and development and sales-dependent milestone payments to Madrigal of less than $ 340 million in the aggregate (over 80 % of such amount being tied to the Company’s achievement of increasingly greater annual worldwide net sales milestones), as well as royalty payments to Madrigal at a rate which, as a percentage of net sales, is in the high single digits for products containing ADX-1612 and mid-single digits for any other Hsp90 inhibitor product. The Company is also obligated under the Madrigal Agreement to pay Madrigal a percentage of certain sublicense revenue that the Company receives in connection with entering into any sublicensing arrangements with any third parties, at a percentage rate which tiers downward from the mid-twenties to low-single digits based on the development stage of the product at the time of the sublicense. The Madrigal Agreement will remain in effect until all payment obligations under the Madrigal Agreement expire. The Company may terminate the Madrigal Agreement in its entirety or on a Madrigal Agreement Product-by Madrigal Agreement Product basis with timely notice to Madrigal. Either party may terminate the Madrigal Agreement for uncured material breach by the other party or upon certain insolvency or bankruptcy proceedings involving the other party, both with timely notice to the other party. In addition, Madrigal has the right to terminate the Madrigal Agreement if the Company, its affiliates, or sublicensees interfere with, challenge the validity or enforceability of, oppose the extension of, or grant of a supplementary protection certificate with respect to any of the Company’s licensed patents under the Madrigal Agreement. In the event of an early termination of the Madrigal Agreement, all rights licensed and developed by the Company under the Madrigal Agreement may revert back to Madrigal. Each party has agreed to indemnify the other party for certain third party claims arising under the Madrigal Agreement. MEEI Agreement The Company is developing ADX-2191 pursuant to an Exclusive License Agreement with Massachusetts Eye and Ear Infirmary (MEEI) originally entered into in July 2016 between MEEI and Helio Vision, Inc., as amended, (MEEI Agreement). The Company assumed the MEEI Agreement in connection with its 2019 acquisition of Helio Vision. Pursuant and subject to the MEEI Agreement, the Company obtained an exclusive, worldwide license from MEEI to develop and commercialize ADX-2191 under certain patents and patent applications, and other licenses to intellectual property (MEEI Patent Rights). The Company has agreed to use commercially reasonable efforts, to develop ADX-2191 and to meet certain specified effort and achievement benchmarks by certain dates. In consideration for the rights licensed under the MEEI Agreement, Helio Vision issued MEEI a number of shares of its preferred stock and Helio Vision agreed to pay non-creditable non-refundable license maintenance fees to MEEI of $ 15,000 on each of the second and third anniversary of the MEEI Agreement, $ 25,000 on each of the fourth and fifth anniversary of the MEEI Agreement and $ 35,000 on the sixth and each subsequent anniversary of the MEEI Agreement during the term of such agreement. In addition, Helio Vision was obligated to make future sales-dependent milestone payments to MEEI of up to the low seven figures in the aggregate, as well as royalty payments to MEEI at a rate which, as a percentage of net sales, is in the low single digits for products that incorporate or use the MEEI Patent Rights in the United States and as a percentage in the low single digits for products that incorporate or use the MEEI Patent Rights outside the United States. The Company is also obligated under the MEEI Agreement to pay MEEI a percentage of certain sublicense revenue that it receives in connection with entering into any sublicensing arrangements with any third parties, at a percentage rate which tiers downward from low-double digits to mid-single digits based on the date of the sublicense. Following the Company’s acquisition of Helio Vision, the Company became obligated to make any future payments owed under the MEEI Agreement. There is no additional equity consideration issuable under the MEEI Agreement. The MEEI Agreement will remain in effect until the expiration date of the last to expire patent licensed under the MEEI Agreement. The Company may terminate the MEEI Agreement with timely written notice to MEEI. MEEI has the right to terminate the MEEI Agreement if it, subject to certain specified cure periods, ceases all business operations with respect to licensed products, fails to pay amounts due under the MEEI Agreement, fail to comply with certain due diligence obligations, defaults in our obligation to maintain insurance, one of our officers is convicted of a felony relating to the manufacture, use, sale or importation of licensed products, we materially breach any provisions of the MEEI Agreement or in the event of its insolvency or bankruptcy. In the event of an early termination of the MEEI Agreement, all rights licensed and developed by the Company under the MEEI Agreement may revert back to MEEI. The Company has agreed to indemnify MEEI for certain claims that may arise under the MEEI Agreement.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	14. LEASES The Company currently leases an office used to conduct business. The exercise of lease renewal options is at the Company’s discretion and the renewal to extend the lease terms are not included in the Company’s Right-Of-Use assets and lease liabilities as they are not reasonably certain of exercise. The Company regularly evaluates the renewal options and when they are reasonably certain of exercise, the Company includes the renewal period in its lease term. As the Company’s lease does not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of the lease payments. In August 2021, the Company entered into a lease amendment extending the lease by 18 months through June 30, 2023. which had an immaterial impact to the balance sheet as of December 31, 2021. For the years ended December 31, 2021 and 2020 , right of use assets obtained in exchange for lease obligations were $ 0.3 million and nil , respectively. As of December 31, 2021, the Company maintained an unamortized Right-Of-Use asset with a corresponding operating lease liability of approximately $ 0.4 million based on the present value of the minimum rental payments in accordance with ASC Topic 842, Leases . The weighted average discount rate used for leases as of December 31, 2021 is 9.1 %. The weighted average lease term as of December 31, 2021 is 1.5 years. The operating lease expense for the year ended December 31, 2021 was $ 0.2 million . Maturities and balance sheet presentation of our lease liabilities for all operating leases as of December 31, 2021 is as follows: Remaining total lease payments $ 381,053 Less: effect of discounting ( 26,214 ) Present value of lease liabilities $ 354,839 Current operating lease liabilities $ 229,607 Non-current operating lease liabilities 125,232 Total $ 354,839 The Company’s gross future minimum payments under all non-cancelable operating leases as of December 31, 2021 are: Total 2022 2023 2024 2025 Operating lease obligations $ 381,053 $ 252,477 $ 128,576 $ — $ —

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	15. SUBSEQUENT EVENTS None.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation – The accompanying consolidated financial statements were prepared in conformity with accounting principles generally accepted in the United States of America (US GAAP).
Risks and Uncertainties	Risks and Uncertainties –The ongoing research and development activities will be subject to extensive regulation by numerous governmental authorities in the United States. Prior to marketing in the United States, any drug developed by the Company must undergo rigorous preclinical and clinical testing and an extensive regulatory approval process implemented by the United States Food and Drug Administration (FDA) under the Food, Drug and Cosmetic Act. The Company has limited experience in conducting and managing the preclinical and clinical testing necessary to obtain regulatory approval. There can be no assurance that the Company will not encounter problems in the clinical trials that will cause the Company or the FDA to delay or suspend clinical trials. The Company’s success will depend in part on its ability to obtain patents and product license rights, maintain trade secrets, and operate without infringing on the property rights of others, both in the United States and other countries. There can be no assurance that patents issued to or licensed by the Company will not be challenged, invalidated, circumvented, or that the rights granted thereunder will provide proprietary protection or competitive advantages to the Company. Based on its current operating plan, the Company believes that its cash and cash equivalents as of December 31, 2021, will be sufficient to fund the Company's currently projected operating expenses through the end of 2023, including potential new drug application (NDA) submissions; initial commercialization of reproxalap, if approved; and continued early and late-stage development of our product candidates in ocular and systemic immune-mediated diseases. As a result of the COVID-19 pandemic, clinical site availability, staffing, and patient recruitment have been negatively affected and the timelines to complete the Company’s clinical trials may be delayed. The Company’s assessment of its liquidity and capital resources includes an estimate of the financial impacts of these changes. The Company will need to secure additional funding in the future, from one or more equity or debt financings, collaborations, or other sources, in order to carry out all of the Company’s planned research and development activities and regulatory activities; commercialize product candidates; or conduct any substantial, additional development requirements requested by the Food and Drug Administration (FDA). Additional funding may not be available to the Company on acceptable terms, or at all. If the Company is unable to secure additional capital, it will be required to significantly decrease the amount of planned expenditures and may be required to cease operations. Curtailment of operations would cause significant delays in the Company’s efforts to develop and introduce its products to market, which is critical to the realization of its business plan and the future operations of the Company.
Use of Estimates	Use of Estimates – The preparation of consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions, including fair value estimates for investments that affect the reported amounts of assets, liabilities, and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis. The most significant estimates in the Company’s financial statements include, but are not limited to, estimates related to clinical trial accruals, estimates related to deferred and accrued research and development costs, and accounting for income taxes and the related valuation allowance. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions.
Segment Information	Segment Information – Operating segments are defined as components of an enterprise about 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 in one segment, which is the identification and development of next-generation medicines to improve the lives of patients with immune-mediated diseases.
Cash and Cash Equivalents	Cash and Cash Equivalents – The Company classifies all highly liquid investments with original maturities of three months or less as cash equivalents and all highly liquid investments with original maturities of greater than three months but less than 12 months as current marketable securities. The Company has a policy of making investments only with commercial institutions that have at least an investment grade credit rating. The Company invests its cash primarily in reverse repurchase agreements (RRAs), government securities and obligations, and money market funds. RRAs are collateralized by deposits in the form of ‘Government Securities and Obligations’ for an amount not less than 102 % of their value. The Company does not record an asset or liability related to the collateral as the Company is not permitted to sell or repledge the associated collateral. The Company has a policy that the collateral has at least an A (or equivalent) credit rating. The Company utilizes a third-party custodian to manage the exchange of funds as well as the requirement that collateral received is maintained at 102% of the value of the RRAs on a daily basis.
Marketable Securities	Marketable Securities – Marketable securities consist of government securities and obligations with original maturities of more than 90 days. Investments are classified as available-for-sale and are recorded on the balance sheet at fair value with unrealized gains or losses reported as a separate component of other comprehensive income/(loss). Management determines the appropriate classification of its investments at the time of purchase and re-evaluates such determination at each balance sheet date.
Fair Value of Financial Instruments	Fair Value of Financial Instruments – Financial instruments including cash equivalents and accounts payable are carried in the financial statements at amounts that approximate their fair value based on the short maturities of those instruments. Marketable securities are carried at fair value and are more fully described in Note 6. The carrying amount of the Company’s credit facility with Hercules Capital, Inc. approximates fair value since the effective interest rate approximates market rates currently available to the Company.
Concentration of Credit Risk	Concentration of Credit Risk – Financial instruments that potentially subject the Company to significant concentrations of credit risk principally consist of cash, cash equivalents and marketable securities, if any. The Company places its cash and cash equivalents and marketable securities with financial institutions which management believes have high credit ratings. As part of its cash and investment management processes, the Company performs periodic evaluations of the credit standing of the financial institutions with whom it maintains deposits.
Intellectual Property	Intellectual Property – The legal and professional costs incurred by the Company to acquire its patent rights are expensed as incurred and included in general and administrative expenses. At December 31, 2021 and 2020, the Company has determined that these expenses have not met the criteria to be capitalized since the future benefits to be derived from the patents is uncertain. Intellectual property related expenses for the years ended December 31, 2021 and 2020 were $ 1.3 million and $ 1.0 million, respectively.
Income Taxes	Income Taxes – The Company follows the provisions of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 740, Income Taxes (ASC 740) , in reporting deferred income taxes. ASC 740 requires a company to recognize deferred tax liabilities and assets for expected future income tax consequences of events that have been recognized in the Company’s financial statements. Under this method, deferred tax assets and liabilities are determined based on temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in the years in which the temporary differences are expected to reverse. Valuation allowances are provided if based on the weight of available evidence, it is more likely than not that some or all the deferred tax assets will not be realized. The Company accounts for uncertain tax positions pursuant to ASC 740 which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes. Management is not aware of any uncertain tax positions.
Research and Development Costs	Research and Development Costs – Research and development (R&D) costs are charged to expense as incurred and relate to salaries, employee benefits, stock-based compensation related to employees, consulting services, other operating costs and expenses associated with preclinical and clinical trial activities. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses. Accrued liabilities are recorded related to those expenses for which vendors have not yet billed us with respect to services provided and/or materials that we have received. Preclinical and clinical trial expenses relate to third-party services, subject-related fees at the sites where the Company’s clinical trials are being conducted, laboratory costs, analysis costs, toxicology studies and investigator fees. Costs associated with these expenses are generally payable on the passage of time or when certain milestones are achieved. Expense is recorded during the period incurred or in the period in which a milestone is achieved. In order to ensure that the Company has adequately provided for preclinical and clinical expenses during the proper period, the Company maintains an accrual to cover these expenses. These accruals are assessed on a quarterly basis and are based on such assumptions as expected total cost, the number of subjects and clinical trial sites and length of the study. Actual results may differ from these estimates and could have a material impact on the Company’s reported results. The Company’s historical accrual estimates have not been materially different from actual costs.
In Process Research and Development	In-process research and development – Assets purchased in an asset acquisition transaction are expensed as in-process research and development (IPR&D) unless the assets acquired are deemed to have an alternative future use, provided that the acquired asset did not also include processes or activities that would constitute a “business” as defined under GAAP, the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, has no established alternative future use. Acquired IPR&D payments are immediately expensed in the period in which they are incurred and include upfront payments, as well as transaction fees and subsequent pre-commercial milestone payments. Research and development costs incurred after the acquisition are expensed as incurred.
Stock-Based Compensation	Stock-Based Compensation – Stock-based payments are accounted for in accordance with the provisions of ASC 718, Compensation – Stock Compensation . For options, the fair value of stock-based payments is estimated, on the date of grant, using the Black-Scholes option pricing model. For restricted stock, fair value is based on the fair value of the stock on the date of grant. The resulting fair value for restricted stock and options expected to vest is recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the applicable restricted stock or option. The Company records the effect of forfeitures and cancellations when they occur.
Comprehensive Loss	Comprehensive Loss – Comprehensive loss is defined as the change in equity during a period from transactions and other events and/or circumstances from non-owner sources. For December 31, 2021, comprehensive loss is equal to the Company’s net loss of $ 57.8 million. For December 31, 2020, comprehensive loss is equal to the Company's net loss of $ 37.6 million and a realized loss on marketable securities of $ 5.9 thousand .
Net Loss Per Share	Net Loss Per Share – The Company computes net loss per share in accordance with the two-class method. Under the two-class method, net loss is allocated between common stock and other participating securities based on their participation rights. The Company has determined that the nonvested shares issued to the Helio founders represents a participating security and as such the nonvested shares are excluded from basic earnings per share. Net losses are not allocated to the nonvested stockholders for computing net loss per share under the two-class method because nonvested stockholders do not have contractual obligations to share in the losses of the Company. Basic earnings per share is calculated by dividing net loss allocable to common stockholders by the weighted average number of common stock outstanding. Diluted net loss per share is computed using the more dilutive of (a) the two-class method, or (b) treasury stock method, as applicable, to the potentially dilutive instruments. The weighted-average number of common shares outstanding gives effect to all potentially dilutive common equivalent shares, including outstanding stock options and restricted stock, warrants, and nonvested shares.
Recent Accounting Pronouncements	Recent Accounting Pronouncements – In June 2016, the FASB issued (ASU) No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 requires that credit losses be reported as an allowance using an expected losses model, representing the entity’s current estimate of credit losses expected to be incurred. The accounting guidance currently in effect is based on an incurred loss model. For available-for-sale debt securities with unrealized losses, this standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. The amendments under ASU 2016-13 are effective for interim and annual fiscal periods beginning after December 15, 2022. The Company is continuing to evaluate the impact of ASU 2016-13 but does not expect the adoption of this ASU to have a material impact on its consolidated financial statements.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Computation of Diluted Weighted-Average Shares Outstanding	The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted-average shares outstanding, because such securities had an antidilutive impact: Years ended December 31, 2021 2020 Options to purchase common stock 4,622,870 4,608,311 Nonvested restricted stock units 501,255 927,189 Nonvested founder shares (1) 10,891 152,856 Total of common stock equivalents 5,135,016 5,688,356 (1) Represents 10,891 and 152,856 shares of common stock that are issued and outstanding but were subject to vesting based on service requirements at December 31, 2021 and 2020 , respectively, and are not included in stockholders’ equity.

Cash, Cash Equivalents and Ma_2

Cash, Cash Equivalents and Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Cash And Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents and Marketable Securities	At December 31, 2021, cash and cash equivalents were comprised of: Carrying Unrecognized Unrecognized Estimated Fair Cash and Cash Cash $ 100,364,523 $ — $ — $ 100,364,523 $ 100,364,523 Money market funds 4,426,466 — — 4,426,466 4,426,466 Reverse repurchase agreements 125,000,000 — — 125,000,000 125,000,000 Total cash and cash equivalents $ 229,790,989 $ — $ — $ 229,790,989 $ 229,790,989 At December 31, 2020, cash and cash equivalents were comprised of: Carrying Unrecognized Unrecognized Estimated Fair Cash and Cash Cash $ 23,494,920 $ — $ — $ 23,494,920 $ 23,494,920 Money market funds 29,363,391 — — 29,363,391 29,363,391 Reverse repurchase agreements 25,000,000 — — 25,000,000 25,000,000 Total cash and cash equivalents $ 77,858,311 $ — $ — $ 77,858,311 $ 77,858,311

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents information about the Company’s assets measured at fair value at December 31, 2021 and December 31, 2020: December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Money market funds (a) $ 4,426,466 $ — $ — $ 4,426,466 Reverse repurchase agreements (b) — 125,000,000 — 125,000,000 Total assets at fair value $ 4,426,466 $ 125,000,000 $ — $ 129,426,466 December 31, 2020 Level 1 Level 2 Level 3 Total Assets: Money market funds (a) $ 29,363,391 $ — $ — $ 29,363,391 Reverse repurchase agreements (b) — 25,000,000 — 25,000,000 Total assets at fair value $ 29,363,391 $ 25,000,000 $ — $ 54,363,391 (a) Money market funds included in cash and cash equivalents in the consolidated balance sheets, are valued at quoted market prices in active markets. Reverse repurchase agreements and U.S. government agency securities, if any, are recorded at fair market values, which are determined based on the most recent observable inputs for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable.

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	12 Months Ended
	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets at December 31, 2021 and 2020 were: December 31, December 31, 2021 2020 Deferred research and development expenses $ 2,404,145 $ 4,793,794 Miscellaneous prepaid expenses and other current assets 557,636 407,163 Total prepaid expenses and other current assets $ 2,961,781 $ 5,200,957

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses at December 31, 2021 and 2020 were: December 31, December 31, 2021 2020 Accrued compensation $ 1,512,885 $ 1,323,138 Contingent consideration payable in stock — 2,500,000 Accrued research and development expenses 8,415,560 3,944,094 Accrued general and administrative expenses 594,908 367,533 Total accrued expenses $ 10,523,353 $ 8,134,765

Credit Facility (Tables)

Credit Facility (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	Long-term debt consisted of the following: December 31, December 31, 2021 2020 Term loan payable $ 15,000,000 $ 15,000,000 End of term charge 703,269 445,464 Unamortized debt issuance costs ( 199,566 ) ( 351,232 ) Less: current portion — ( 3,659,776 ) Total long-term debt $ 15,503,703 $ 11,434,456
Schedule of Principal Payments Including End of Term Charges	Future principal payments, including the End of Term Charge, are as follows for the years ending December 31: 2022 $ — 2023 16,042,500 Total $ 16,042,500

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Components of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities at December 31, 2021 and 2020 are as follows: Years ended December 31, 2021 2020 Deferred Tax Assets Federal & state NOL carryforward $ 61,308,787 $ 48,273,248 Federal & state R&D credit 9,200,758 6,375,229 Intangibles – net 78,378 78,378 Accounts payable and accrued 2,301,117 192,200 Stock options 3,906,501 3,762,247 Other items 127,791 94,020 Gross deferred tax assets 76,923,332 58,775,322 Valuation allowance ( 76,827,203 ) ( 58,711,582 ) Deferred tax assets, net $ 96,129 $ 63,740 Deferred Tax Liabilities Right of use asset ( 96,129 ) ( 63,740 ) TOTAL $ — $ —
Components of Income Tax Benefit	The components of the income tax benefit for the years ended December 31, 2021 and 2020, are as follows: Years ended December 31, 2021 2020 Deferred Taxes Federal $ — $ ( 338,924 ) State — ( 140,341 ) Total income tax benefit $ — $ ( 479,265 )
Summary of Statutory Tax Rates and Effective Tax Rates	A reconciliation of the federal statutory tax rate of 21 % to the Company’s effective income tax rates are as follows: Years ended December 31, 2021 2020 Statutory tax rate 21.00 % 21.00 % State taxes, net of federal benefits 6.65 % 5.06 % Federal research and development credits 4.29 % 3.28 % Change in valuation allowance ( 31.35 ) % ( 22.76 ) % Stock-based compensation ( 0.73 ) % ( 5.85 ) % Other 0.14 % 0.55 % Effective tax rate ( 0.00 ) % 1.28 %

Stock Incentive Plan (Tables)

Stock Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2021
Schedule of Stock-Based Compensation Expense	The amounts included in the consolidated statements of operations relating to stock-based compensation associated with the two equity incentive plans, performance cash awards, and Helio founders’ shares are as follows: Years ended December 31, 2021 2020 Research and development expenses $ 3,562,181 $ 3,798,141 General and administrative expenses 3,545,846 3,285,669 Total stock-based compensation expense $ 7,108,027 $ 7,083,810
Summary of Activity Relating to Stock Options	The following table summarizes option activity under the incentive plans for the year ended December 31, 2021: Number of Weighted Weighted Aggregate Outstanding at December 31, 2020 4,608,311 $ 5.73 $ 7,492,474 Granted 965,169 11.40 - Cancelled/Forfeited ( 316,396 ) 5.23 2,217,529 Exercised ( 634,214 ) 7.29 2,450,104 Outstanding at December 31, 2021 4,622,870 $ 6.73 6.71 $ 1,268,089 Exercisable at December 31, 2021 3,134,196 $ 5.90 5.79 $ 1,150,723
Summary of Activity Relating to Restricted Stock Units	The table below summarizes activity relating to RSUs for the year ended December 31, 2021 : Number Outstanding at December 31, 2020 927,189 Granted 46,619 Cancelled/Forfeited ( 185,610 ) Vested/released ( 286,943 ) Outstanding at December 31, 2021 501,255
Schedule of Fair Value of Employee Stock Purchase Plan Assumptions	The fair value of the purchase rights granted under this plan was estimated on the date of grant using the Black-Scholes option-pricing model using assumptions as shown below: December 31, December 31, Expected dividend yield 0 % 0 % Anticipated volatility 81.76 % - 82.87 % 80.66 % - 82.61 % Stock price $ 6.53 - $ 11.31 $ 4.17 - $ 5.96 Exercise price $ 6.53 - $ 11.31 $ 4.17 - $ 5.96 Expected life (years) 0.50 0.50 Risk free interest rate 0.05 % - 0.09 % 0.17 % - 1.57 %
Summary of Employee Stock Purchase Plan Activity	A summary of the weighted-average grant-date fair value, shares issued and total stock-based compensation expense recognized related to the 2016 ESPP for the years ended December 31, 2021 and 2020 are as follows: December 31, December 31, Weighted-average grant-date fair value $ 2.98 $ 2.13 Total shares issued 12,092 30,254 Total stock-based compensation expense $ 45,190 $ 34,224
Employee Stock Options [Member]
Schedule of Fair Value of Stock Option Assumptions	The assumptions used in determining fair value of the employee stock options for the years ended December 31, 2021 and 2020, are as follows: December 31, December 31, Expected dividend yield 0 % 0 % Anticipated volatility 81.73 % - 83.50 % 75.83 % - 82.83 % Stock price $ 8.33 - $ 12.97 $ 2.98 - $ 6.77 Exercise price $ 8.33 - $ 12.97 $ 2.98 - $ 6.77 Expected life (years) 5.50 - 6.08 5.50 - 6.25 Risk free interest rate 0.88 % - 1.67 % 0.39 % - 1.71 %

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Schedule of Maturities and Balance Sheet Presentation of Lease Liabilities	Maturities and balance sheet presentation of our lease liabilities for all operating leases as of December 31, 2021 is as follows: Remaining total lease payments $ 381,053 Less: effect of discounting ( 26,214 ) Present value of lease liabilities $ 354,839 Current operating lease liabilities $ 229,607 Non-current operating lease liabilities 125,232 Total $ 354,839 The Company’s gross future minimum payments under all non-cancelable operating leases as of December 31, 2021 are: Total 2022 2023 2024 2025 Operating lease obligations $ 381,053 $ 252,477 $ 128,576 $ — $ —

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021USD ($)Segment	Dec. 31, 2020USD ($)
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of segment | Segment	1
Investment maturity period	three months or less
Marketable securities maturity period	90 days
Unrealized gain on marketable securities	$ 0	$ (5,866)
Net loss	57,776,274	37,553,729
Intellectual Property [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Legal expense	$ 1,300,000	$ 1,000,000
Minimum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Percentage of Collateral Deposits under Reverse Repurchase Agreement	102.00%

Helio vision acquisition - Addi

Helio vision acquisition - Additional Information (Detail) - USD ($)	Jan. 28, 2019	Jan. 31, 2021	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Business Acquisition [Line Items]
Share-based compensation award, vesting period						4 years
Allocated Share Based Compensation Expense				$ 7,108,027	$ 7,083,810
Income tax benefit				0	(479,265)
Acquired in-process research and development				0	1,754,265
Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business combination, stock issued	1,160,444	246,562
Contingent consideration payable in stock					2,500,000
Income tax benefit					500,000
Common Stock after FDA Approval prior to 10th Anniversary [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business Combination Contingent Consideration Liability	$ 10,000,000
Common Stock after FDA Approval Prior to 12th Anniversary [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business Combination Contingent Consideration Liability	$ 2,500,000
Common Stock after FDA Approval Prior to 12th Anniversary [Member] | Maximum [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration stock to be issued	5,248,885
Tax Gross-up Payment in Event of Change of Control or Divesture [Member] | Maximum [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business Combination Contingent Consideration Liability	$ 1,000,000
Research and Development Expenses [Member]
Business Acquisition [Line Items]
Allocated Share Based Compensation Expense				3,562,181	3,798,141
Founders [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business combination, stock issued	568,627
Founders [Member] | Service Based Awards [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Share-based compensation award, vesting period	3 years
Vesting Percentage Of Shares Of Common Stock Issued Former Security Holders And Advisor	98.00%
Founders [Member] | Restricted Stock [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Share-based compensation award, vesting period	3 years
Founders [Member] | Restricted Stock [Member] | Research and Development Expenses [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Allocated Share Based Compensation Expense				$ 1,200,000	1,300,000
Non Founders [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business combination, stock issued	591,817
Milestone [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Business combination, stock issued			246,562
Milestone [Member] | Restricted Stock [Member] | Research and Development Expenses [Member] | Helio Vision, Inc [Member]
Business Acquisition [Line Items]
Allocated Share Based Compensation Expense					1,200,000
Expense related to the Milestone IPR&D					$ 1,800,000

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Diluted Weighted-Average Shares Outstanding (Detail) - shares		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents		5,135,016	5,688,356
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents		4,622,870	4,608,311
Nonvested restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents		501,255	927,189
Nonvested Founder Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents	[1]	10,891	152,856
[1]	Represents 10,891 and 152,856 shares of common stock that are issued and outstanding but were subject to vesting based on service requirements at December 31, 2021 and 2020 , respectively, and are not included in stockholders’ equity.

Net Loss Per Share - Computat_2

Net Loss Per Share - Computation of Diluted Weighted-Average Shares Outstanding (Parenthetical) (Detail) - shares	Dec. 31, 2021	Dec. 31, 2020
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of common stock shares issued and outstanding subject of vesting shares based on service requirements	10,891	152,856

Cash, Cash Equivalents and Ma_3

Cash, Cash Equivalents and Marketable Securities - Schedule of Cash and Cash Equivalents (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Cash Cash Equivalents And Marketable Securities [Line Items]
Cash	$ 100,364,523	$ 23,494,920
Money market funds	4,426,466	29,363,391
Reverse repurchase agreements	125,000,000	25,000,000
Total Cash and cash equivalents	229,790,989	77,858,311
Cash and Cash Equivalents	0	0
Cash [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value	100,364,523	23,494,920
Cash and Cash Equivalents	100,364,523	23,494,920
Money Market Funds [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value	4,426,466	29,363,391
Cash and Cash Equivalents	4,426,466	29,363,391
Reverse Repurchase Agreements [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value	125,000,000	25,000,000
Cash and Cash Equivalents	125,000,000	25,000,000
Total Cash and cash equivalents [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value	229,790,989	77,858,311
Cash and Cash Equivalents	$ 229,790,989	$ 77,858,311

Cash, Cash Equivalents and Ma_4

Cash, Cash Equivalents and Marketable Securities - Additional Information (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Cash And Cash Equivalents [Abstract]
Marketable Securities	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)		Dec. 31, 2021	Dec. 31, 2020
Assets:
Total assets at fair value		$ 129,426,466	$ 54,363,391
Level 1 [Member]
Assets:
Total assets at fair value		4,426,466	29,363,391
Level 2 [Member]
Assets:
Total assets at fair value		125,000,000	25,000,000
Level 3 [Member]
Assets:
Total assets at fair value		0	0
Money Market Funds [Member]
Assets:
Total assets at fair value	[1]	4,426,466	29,363,391
Money Market Funds [Member] | Level 1 [Member]
Assets:
Total assets at fair value	[1]	4,426,466	29,363,391
Money Market Funds [Member] | Level 2 [Member]
Assets:
Total assets at fair value	[1]	0	0
Money Market Funds [Member] | Level 3 [Member]
Assets:
Total assets at fair value	[1]	0	0
Reverse Repurchase Agreements [Member]
Assets:
Total assets at fair value	[2]	125,000,000	25,000,000
Reverse Repurchase Agreements [Member] | Level 1 [Member]
Assets:
Total assets at fair value	[2]	0	0
Reverse Repurchase Agreements [Member] | Level 2 [Member]
Assets:
Total assets at fair value	[2]	125,000,000	25,000,000
Reverse Repurchase Agreements [Member] | Level 3 [Member]
Assets:
Total assets at fair value	[2]	$ 0	$ 0
[1]	Money market funds included in cash and cash equivalents in the consolidated balance sheets, are valued at quoted market prices in active markets.
[2]	Reverse repurchase agreements and U.S. government agency securities, if any, are recorded at fair market values, which are determined based on the most recent observable inputs for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable.

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]
Deferred research and development expenses	$ 2,404,145	$ 4,793,794
Miscellaneous prepaid expenses and other current assets	557,636	407,163
Total prepaid expenses and other current assets	$ 2,961,781	$ 5,200,957

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued compensation	$ 1,512,885	$ 1,323,138
Contingent consideration payable in stock	0	2,500,000
Accrued research and development expenses	8,415,560	3,944,094
Accrued general and administrative expenses	594,908	367,533
Total accrued expenses	$ 10,523,353	$ 8,134,765

Credit Facility - Additional In

Credit Facility - Additional Information (Detail) - USD ($)	Apr. 20, 2021	Dec. 31, 2021
Line Of Credit Facility [Line Items]
Proceeds from Long-term lines of credit		$ 16,042,500
Hercules Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility amount	$ 35,000,000	$ 60,000,000
Debt instrument annual interest rate		9.10%
Interest payment period		May 1, 2021
Interest payment extension period		May 1, 2023
Commitment charge		$ 25,000
Transaction costs		273,186
Credit facility fee		$ 375,000
Credit facility commitment fee percentage		6.95%
Credit facility prepayment fee percentage		1.50%
Credit facility, interest rate		10.80%
Loan funded prior to the date of amendment	15,000,000
Hercules Credit Facility [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Loan agreement right to purchase aggregate amount of equity securities		$ 2,000,000
Hercules Credit Facility [Member] | Prime Rate [Member]
Line Of Credit Facility [Line Items]
Debt instrument variable annual interest rate		3.10%
Hercules Credit Facility [Member] | Term Loan Advance One [Member]
Line Of Credit Facility [Line Items]
Credit facility amount		$ 5,000,000
Hercules Credit Facility [Member] | Term Loan Advance Two [Member]
Line Of Credit Facility [Line Items]
Proceeds from Long-term lines of credit		15,000,000
Hercules Credit Facility [Member] | Term Loan Advance Three [Member]
Line Of Credit Facility [Line Items]
Proceeds from Long-term lines of credit		15,000,000
Hercules Credit Facility [Member] | Term Loan Advance Four [Member]
Line Of Credit Facility [Line Items]
Proceeds from Long-term lines of credit		15,000,000
Hercules Credit Facility [Member] | Term Loan Advance Five [Member]
Line Of Credit Facility [Line Items]
Proceeds from Long-term lines of credit	10,000,000	$ 10,000,000
Debt instrument, increase amount	$ 20,000,000

Credit Facility - Schedule of L

Credit Facility - Schedule of Long-Term Debt (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Line Of Credit Facility [Abstract]
Term loan payable	$ 15,000,000	$ 15,000,000
End of term charge	703,269	445,464
Unamortized debt issuance costs	(199,566)	(351,232)
Less: current portion	0	(3,659,776)
Total long-term debt	$ 15,503,703	$ 11,434,456

Credit Facility - Schedule of P

Credit Facility - Schedule of Principal Payments Incuding End of Term Charges (Detail)	Dec. 31, 2021USD ($)
Line Of Credit Facility [Abstract]
2022	$ 0
2023	16,042,500
Total	$ 16,042,500

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended				2 Months Ended	12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2018	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, voting rights						Each share of common stock is entitled to one vote.
Issuance of common stock, net of issuance costs						$ 189,811,611	$ 40,716,544
Proceeds from issuance of common stock, net of issuance costs						$ 189,811,611	$ 40,716,544
Common Voting Stock [Member]
Class Of Stock [Line Items]
Issuance of common stock, net of issuance costs, Shares						18,091,947	9,351,749
Issuance of common stock, net of issuance costs						$ 18,092	$ 9,352
2018 Jefferies Sales Agreement [Member] | Jefferies LLC [Member]
Class Of Stock [Line Items]
Issuance of common stock, net of issuance costs, Shares							9,351,749
Proceeds from issuance of common stock, net of issuance costs							$ 40,700,000
Volume-weighted average price							$ 4.62
2018 Jefferies Sales Agreement [Member] | Jefferies LLC [Member] | Maximum [Member]
Class Of Stock [Line Items]
Expected aggregate gross proceeds from issuance of stock				$ 50,000,000
2021 Jefferies Sales Agreement [Member] | Maximum [Member]
Class Of Stock [Line Items]
Proceeds from issuance of common stock, net of issuance costs		$ 100,000,000
Underwritten Public Offering [Member]
Class Of Stock [Line Items]
Proceeds from issuance of common stock, net of issuance costs			$ 70,000,000		$ 119,800,000
Underwritten Public Offering [Member] | Common Voting Stock [Member]
Class Of Stock [Line Items]
Issuance of common stock, net of issuance costs, Shares			7,900,000		10,200,000
Shares issued, price per share	$ 12.50		$ 9.50		$ 12.50
Issuance of common stock, net of issuance costs	$ 127,800,000		$ 74,700,000
Employee Stock Options [Member]
Class Of Stock [Line Items]
Common stock reserved for issuance of shares						4,622,870
Two Thousand And Thirteen Incentive Plan [Member]
Class Of Stock [Line Items]
Common stock reserved for issuance of shares						3,044,303
2016 Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Common stock reserved for issuance of shares						1,233,557

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Current provision for income tax benefit	$ 0	$ (479,265)
Deferred tax assets valuation allowance	100.00%
Net operating loss carryforwards expire period	2041
Increasing in research activities expire period	2041
Statutory tax rate	21.00%	21.00%
Change in valuation allowance	$ 18,100,000
Federal orphan drug tax credit carryforward	$ 1,000,000
Maximum [Member]
Income Tax Contingency [Line Items]
Statutory tax rate	50.00%
State and Federal [Member]
Income Tax Contingency [Line Items]
Current provision for income tax benefit	$ 0
Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards	226,000,000
Increasing in research activities	6,900,000
State [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards	219,000,000
Increasing in research activities	$ 1,600,000

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets
Federal & state NOL carryforward	$ 61,308,787	$ 48,273,248
Federal & state R&D credit carryforward	9,200,758	6,375,229
Intangibles – net	78,378	78,378
Accounts payable and accrued expenses	2,301,117	192,200
Stock options	3,906,501	3,762,247
Other items	127,791	94,020
Gross deferred tax assets	76,923,332	58,775,322
Valuation allowance	(76,827,203)	(58,711,582)
Deferred tax assets, net	96,129	63,740
Deferred Tax Liabilities
Right of use asset	(96,129)	(63,740)
TOTAL	$ 0	$ 0

Income Taxes - Components of In

Income Taxes - Components of Income Tax Benefit (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Deferred Taxes
Federal	$ 0	$ (338,924)
State		(140,341)
Total income tax benefit	$ 0	$ (479,265)

Income Taxes - Summary of Statu

Income Taxes - Summary of Statutory Tax Rates and Effective Tax Rates (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Statutory tax rate	21.00%	21.00%
State taxes, net of federal benefits	6.65%	5.06%
Federal research and development credits	4.29%	3.28%
Change in valuation allowance	(31.35%)	(22.76%)
Stock-based compensation	(0.73%)	(5.85%)
Other	0.14%	0.55%
Effective tax rate	(0.00%)	1.28%

Stock Incentive Plan - Addition

Stock Incentive Plan - Additional Information (Detail) - USD ($)	Jan. 01, 2022	Jan. 02, 2016	Jan. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase of shares of common stock				4,622,870	4,608,311
Exercise price per share of common stock				$ 6.73	$ 5.73
Share-based compensation award, vesting period							4 years
Fair value of a common stock percentage				100.00%
Unamortized stock-based compensation				$ 7,500,000
Weighted average recognition period				2 years 6 months
Share based compensation expense				$ 400,000
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted in term years							10 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation award, vesting period				4 years
Weighted average grant date fair value of shares				$ 7.95	2.57
Unamortized stock-based compensation				$ 1.7
Weighted average grant date fair value				$ 11.71	$ 3.78
Weighted average remaining recognition period				1 year 10 months 28 days
Aggregate intrinsic value of options outstanding				$ 3
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield			0.00%		0.00%
Cash dividend paid				$ 0
Employee Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield				0.00%
Performance Cash Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted period					4 years	4 years
2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase of shares of common stock				398,547
Exercise price per share of common stock				$ 1.52
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase of shares of common stock				4,224,323
Exercise price per share of common stock				$ 7.23
Common stock available for issuance	6,529,829			3,044,303
Common stock issued	3,485,526
Amended 2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of increase in common stock outstanding		6.00%
2016 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance				1,233,557
Expected dividend yield				0.00%	0.00%
Weighted average grant date fair value				$ 2.98	$ 2.13
Issuance of common stock authorized				414,639
Percentage increase in number of shares of common stock reserved for issuance				1.00%
Share-based compensation arrangement by share-based payment award, closing price on the applicable offering commencement				85.00%
Share-based compensation arrangement by share-based payment award, closing price on the applicable offering termination date				85.00%
Share-based compensation arrangement by share-based payment award, description				In March 2016, the Company’s board of directors approved the 2016 Employee Stock Purchase Plan (2016 ESPP), which became effective in June 2016 following the approval of the Company’s stockholders. The 2016 ESPP initially authorized the issuance of up to a total of 414,639 shares of the Company’s common stock to participating employees. The number of shares reserved for issuance under the 2016 ESPP automatically increases on the first business day of each fiscal year, commencing in 2017, by a number equal to the lower of (i) 1% of the shares of common stock outstanding on the last business day of the prior fiscal year; or (ii) the number of shares determined by the Company’s Board of Directors. Unless otherwise determined by the administrator of the 2016 ESPP, two offering periods of six months’ duration will begin each year on January 1 and July 1. Participating employees purchase stock under the 2016 ESPP at a price equal to the lower of 85% of the closing price on the applicable offering commencement date or 85% of the closing price on the applicable offering termination date.

Stock Incentive Plan - Schedule

Stock Incentive Plan - Schedule of Stock-Based Compensation Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 7,108,027	$ 7,083,810
Research and Development Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	3,562,181	3,798,141
General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 3,545,846	$ 3,285,669

Stock Incentive Plan - Summary

Stock Incentive Plan - Summary of Stock Option Activity (Detail)	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares Outstanding, Beginning Balance | shares	4,608,311
Number of Shares, Granted | shares	965,169
Number of Shares,Cancelled/Forfeited | shares	(316,396)
Number of Shares, Exercised | shares	(634,214)
Number of Shares Outstanding, Ending Balance | shares	4,622,870
Number of Shares Exercisable, Ending Balance | shares	3,134,196
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 5.73
Weighted Average Exercise Price, Granted | $ / shares	11.40
Weighted Average Exercise Price, Cancelled/Forfeited | $ / shares	5.23
Weighted Average Exercise Price, Exercised | $ / shares	7.29
Weighted Average Exercise Price, Ending Balance | $ / shares	6.73
Weighted Average Exercise Price Exercisable, Ending Balance | $ / shares	$ 5.90
Weighted Average Contractual Term, Outstanding	6 years 8 months 15 days
Weighted Average Contractual Term, Exercisable	5 years 9 months 14 days
Aggregate Intrinsic Value, Outstanding | $	$ 7,492,474	[1]
Aggregate Intrinsic Value, Granted | $	0	[1]
Aggregate Intrinsic Value, Cancelled/Forfeited | $	2,217,529	[1]
Aggregate Intrinsic Value, Excercised | $	2,450,104	[1]
Aggregate Intrinsic Value, Outstanding | $	1,268,089	[1]
Aggregate Intrinsic Value, Exercisable | $	$ 1,150,723	[1]
[1]	The aggregate intrinsic value in this table was calculated on the positive difference, if any, between the closing price per share of the Company’s common stock on December 31, 2021 of $ 4.00 and the per share exercise price of the underlying options.

Stock Incentive Plan - Summar_2

Stock Incentive Plan - Summary of Stock Option Activity (Parenthetical) (Detail)	Dec. 31, 2021$ / shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Closing market value of common stock	$ 4

Stock Incentive Plan - Schedu_2

Stock Incentive Plan - Schedule of Fair Value of Stock Option Assumptions (Detail) - $ / shares	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price		$ 4
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%		0.00%
Employee Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield		0.00%
Anticipated volatility		81.73%	75.83%
Stock price		$ 8.33	$ 2.98
Exercise price		$ 8.33	$ 2.98
Expected life (years)		5 years 6 months	5 years 6 months
Risk free interest rate		0.88%	0.39%
Employee Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anticipated volatility		83.50%	82.83%
Stock price		$ 12.97	$ 6.77
Exercise price		$ 12.97	$ 6.77
Expected life (years)		6 years 29 days	6 years 3 months
Risk free interest rate		1.67%	1.71%

Stock Incentive Plan - Summar_3

Stock Incentive Plan - Summary of Activity Relating to Restricted Stock Units (Detail) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2021shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Outstanding, Beginning Balance	927,189
Granted	46,619
Cancelled/Forfeited	(185,610)
Vested/released	(286,943)
Number of Shares Outstanding, Ending Balance	501,255

Stock Incentive Plan - Schedu_3

Stock Incentive Plan - Schedule of Fair Value of Employee Stock Purchase Plan Assumptions (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price	$ 4
2016 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%
Expected life (years)	6 months	6 months
2016 Employee Stock Purchase Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anticipated volatility	81.76%	80.66%
Stock price	$ 6.53	$ 4.17
Exercise price	$ 6.53	$ 4.17
Risk free interest rate	0.05%	0.17%
2016 Employee Stock Purchase Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anticipated volatility	82.87%	82.61%
Stock price	$ 11.31	$ 5.96
Exercise price	$ 11.31	$ 5.96
Risk free interest rate	0.09%	1.57%

Stock Incentive Plan - Summar_4

Stock Incentive Plan - Summary of Employee Stock Purchase Plan Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 7,108,027	$ 7,083,810
2016 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share	$ 2.98	$ 2.13
Issuance of common stock, employee stock purchase plan, Shares	12,092	30,254
Total stock-based compensation expense	$ 45,190	$ 34,224

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021USD ($)
Commitments And Contingencies [Line Items]
Outstanding material claims	$ 0
Reserve for indemnification	0
Madrigal Agreement [Member]
Commitments And Contingencies [Line Items]
License fee	$ 250,000
Percentage over future regulatory, development and sales-dependent milestone payments	80.00%
Madrigal Agreement [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Future regulatory, development and sales-dependent milestone payments	$ 340,000,000
MEEI Agreement [Member]
Commitments And Contingencies [Line Items]
Additional equity consideration issuable	0
MEEI Agreement [Member] | Second and Third Anniversary [Member]
Commitments And Contingencies [Line Items]
Non-creditable non-refundable license maintenance fees	15,000
MEEI Agreement [Member] | Fourth and Fifth Anniversary [Member]
Commitments And Contingencies [Line Items]
Non-creditable non-refundable license maintenance fees	25,000
MEEI Agreement [Member] | Sixth and Subsequent Anniversary [Member]
Commitments And Contingencies [Line Items]
Non-creditable non-refundable license maintenance fees	$ 35,000

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Lease extended term	18 months
Operating lease liability		$ 354,839
Right of use assets obtained in exchange for lease obligations		$ 300,000	$ 0
Operating leases, weighted average remaining lease term (years)		1 year 6 months
Operating leases, weighted average discount rate		9.10%
Operating lease, expense		$ 200,000

Leases - Schedule of Maturities

Leases - Schedule of Maturities and Balance Sheet Presentation of Lease Liabilities (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2022 remaining total lease payments	$ 381,053
Less: effect of discounting	(26,214)
Present value of lease liabilities	354,839
Current operating lease liabilities	229,607	$ 233,310
Non-current operating lease liabilities	125,232	$ 0
Present value of lease liabilities	$ 354,839

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments Under Non-Cancelable Operating Leases (Detail)	Dec. 31, 2021USD ($)
Leases [Abstract]
2022 remaining total lease payments	$ 381,053
Operating lease obligations, 2022	252,477
Operating lease obligations, 2023	128,576
Operating lease obligations, 2024	0
Operating lease obligations, 2025	$ 0