Aldeyra Therapeutics (ALDX) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 03, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Trading Symbol	ALDX
Entity Registrant Name	ALDEYRA THERAPEUTICS, INC.
Entity Central Index Key	0001341235
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding		38,820,347
Entity Current Reporting Status	Yes
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.001 par value per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Entity File Number	001-36332
Entity Tax Identification Number	20-1968197
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
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 71,175,507	$ 16,425,830
Cash equivalent - reverse repurchase agreements	15,000,000	28,000,000
Marketable securities		28,938,545
Prepaid expenses and other current assets	2,017,273	1,804,450
Total current assets	88,192,780	75,168,825
Right-of-use assets	52,195	201,007
Fixed assets, net	79,455	148,449
Total assets	88,324,430	75,518,281
Current liabilities:
Accounts payable	123,900	808,302
Accrued expenses	4,018,635	11,873,122
Current portion of credit facility	2,259,417
Current portion of operating lease liabilities	58,720	226,328
Total current liabilities	6,460,672	12,907,752
Long-term debt	12,693,311	14,528,212
Total liabilities	19,153,983	27,435,964
Commitments and contingencies (Notes 13 and 14)
Stockholders' equity:
Common stock, voting, $0.001 par value; 150,000,000 authorized and 38,631,709 and 28,656,832 shares issued and outstanding, respectively	38,632	28,657
Additional paid-in capital	294,755,363	247,409,793
Accumulated other comprehensive income		5,866
Accumulated deficit	(225,623,548)	(199,361,999)
Total stockholders’ equity	69,170,447	48,082,317
Total liabilities and stockholders’ equity	$ 88,324,430	$ 75,518,281

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	38,631,709	28,656,832
Common stock, shares outstanding	38,631,709	28,656,832

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development	$ 6,133,580	$ 16,223,972	$ 17,653,058	$ 34,737,420
Acquired in-process research and development		(47,102)		6,500,602
General and administrative	2,255,617	2,839,319	7,480,461	8,940,771
Loss from operations	(8,389,197)	(19,016,189)	(25,133,519)	(50,178,793)
Other income (expense):
Interest income	5,215	330,329	287,025	1,262,378
Interest expense	(489,191)	(29,154)	(1,415,055)	(59,766)
Total other income (expense), net	(483,976)	301,175	(1,128,030)	1,202,612
Loss before income taxes	(8,873,173)	(18,715,014)	(26,261,549)	(48,976,181)
Income tax benefit				1,309,973
Net loss	$ (8,873,173)	$ (18,715,014)	$ (26,261,549)	$ (47,666,208)
Net loss per share - basic and diluted	$ (0.23)	$ (0.69)	$ (0.81)	$ (1.77)
Weighted average common shares outstanding - basic and diluted	37,796,946	27,111,600	32,395,217	26,928,725

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (8,873,173)	$ (18,715,014)	$ (26,261,549)	$ (47,666,208)
Other comprehensive (loss) income:
Unrealized gain (loss) on marketable securities, net of tax	(4,754)	(7,687)	(5,866)	14,990
Total other comprehensive (loss) income	(4,754)	(7,687)	(5,866)	14,990
Comprehensive loss	$ (8,877,927)	$ (18,722,701)	$ (26,267,415)	$ (47,651,218)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Total	Helio Vision IncFounders [Member]	Common Voting Stock [Member]	Common Voting Stock [Member]Helio Vision IncFounders [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Helio Vision IncFounders [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2018	$ 86,617,979		$ 26,244		$ 225,136,127		$ (9,224)	$ (138,535,168)
Beginning Balance, Shares at Dec. 31, 2018			26,244,435
Stock-based compensation	6,133,990				6,133,990
Issuance of common stock, acquisition of Helio Vision, Inc.		$ 4,862,731		$ 724		$ 4,862,007
Issuance of common stock, acquisition of Helio Vision, Inc., Shares				724,518
Issuance of common stock, net of issuance costs	720,964		$ 84		720,880
Issuance of common stock, net of issuance costs, Shares			83,557
Issuance of common stock, employee stock purchase plan	194,848		$ 35		194,813
Issuance of common stock, employee stock purchase plan, Shares			34,253
Issuance of common stock, vested restricted stock awards			$ 65		(65)
Issuance of common stock for vested restricted stock units, Shares			65,012
Other comprehensive income (loss)	14,990						14,990
Net loss	(47,666,208)							(47,666,208)
Ending Balance at Sep. 30, 2019	50,879,294		$ 27,152		237,047,752		5,766	(186,201,376)
Ending Balance, Shares at Sep. 30, 2019			27,151,775
Beginning Balance at Jun. 30, 2019	67,333,370		$ 26,987		234,779,291		13,453	(167,486,361)
Beginning Balance, Shares at Jun. 30, 2019			26,986,936
Stock-based compensation	2,152,938				2,152,938
Issuance of common stock, acquisition of Helio Vision, Inc.			$ 142		(142)
Issuance of common stock, acquisition of Helio Vision, Inc., Shares			142,155
Issuance of common stock, employee stock purchase plan	115,688		$ 23		115,665
Issuance of common stock, employee stock purchase plan, Shares			22,684
Other comprehensive income (loss)	(7,687)						(7,687)
Net loss	(18,715,015)							(18,715,015)
Ending Balance at Sep. 30, 2019	50,879,294		$ 27,152		237,047,752		5,766	(186,201,376)
Ending Balance, Shares at Sep. 30, 2019			27,151,775
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	5,453,520				5,453,520
Issuance of common stock, acquisition of Helio Vision, Inc.			$ 238		(238)
Issuance of common stock, acquisition of Helio Vision, Inc., Shares			237,834
Issuance of common stock, net of issuance costs	40,716,543		$ 9,352		40,707,191
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		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 for vested restricted stock units, Shares			135,796
Other comprehensive income (loss)	(5,866)						(5,866)
Net loss	(26,261,549)							(26,261,549)
Ending Balance at Sep. 30, 2020	69,170,447		$ 38,632		294,755,363			(225,623,548)
Ending Balance, Shares at Sep. 30, 2020			38,631,709
Beginning Balance at Jun. 30, 2020	52,789,666		$ 32,997		269,502,290		4,754	(216,750,375)
Beginning Balance, Shares at Jun. 30, 2020			32,997,346
Stock-based compensation	1,757,479				1,757,479
Issuance of common stock, acquisition of Helio Vision, Inc.			$ 36		(36)
Issuance of common stock, acquisition of Helio Vision, Inc., Shares			35,783
Issuance of common stock, net of issuance costs	22,446,055		$ 5,378		22,440,677
Issuance of common stock, net of issuance costs, Shares			5,377,681
Issuance of common stock, exercise of stock options	998,097		$ 205		997,892
Issuance of common stock, exercise of stock options, Shares			204,796
Issuance of common stock, employee stock purchase plan	57,077		$ 16		57,061
Issuance of common stock, employee stock purchase plan, Shares			16,103
Other comprehensive income (loss)	(4,754)						$ (4,754)
Net loss	(8,873,173)							(8,873,173)
Ending Balance at Sep. 30, 2020	$ 69,170,447		$ 38,632		$ 294,755,363			$ (225,623,548)
Ending Balance, Shares at Sep. 30, 2020			38,631,709

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (26,261,549)	$ (47,666,208)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development		6,500,602
Deferred taxes		(1,309,973)
Stock-based compensation	5,453,520	6,133,990
Non-cash interest expense	424,516	59,766
Accretion on debt securities available for sale, net	(91,231)	(474,771)
Depreciation and amortization expense	217,806	72,284
Change in assets and liabilities:
Prepaid expenses and other current assets	(212,823)	404,264
Accounts payable	(684,402)	(3,082,081)
Accrued expenses	(8,022,095)	5,604,224
Net cash used in operating activities	(29,176,258)	(33,757,903)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of fixed assets		(9,529)
Purchases of marketable securities	(5,776,090)	(36,860,554)
Sales and maturities of marketable securities	34,800,000	59,000,000
Net cash provided by investing activities	29,023,910	22,762,007
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of issuance costs	40,716,543	720,964
Proceeds from exercise of stock options	1,058,516
Proceeds from employee stock purchase plan	126,966	194,849
Proceeds from long-term debt		14,450,000
Debt issuance costs paid in cash		(123,186)
Net cash provided by financing activities	41,902,025	15,242,627
NET INCREASE IN CASH AND CASH EQUIVALENTS	41,749,677	4,246,731
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	44,425,830	47,357,472
CASH AND CASH EQUIVALENTS, END OF PERIOD	86,175,507	51,604,203
Helio Vision Inc
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development	6,500,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash acquired in Helio asset acquisition		632,090
SUPPLEMENTAL INFORMATION AND DISCLOSURES OF NONCASH ACTIVITIES:
Assets acquired		75,632
Liabilities acquired		637,994
Fair value of securities issued		4,862,731
Right-of-use assets acquired through operating leases		$ 386,060
Cash paid during the period for interest	$ 1,042,708

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. NATURE OF BUSINESS Aldeyra Therapeutics, Inc., together with its wholly-owned subsidiaries (the “Company” or “Aldeyra”), a Delaware corporation, is a clinical-stage biotechnology company focused on the development of novel therapies with the potential to improve 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

Basis of Presentation	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	2. BASIS OF PRESENTATION The accompanying interim condensed consolidated financial statements and related disclosures are unaudited and have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the instructions to Form 10-Q and Regulation S-X. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company’s audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the Securities and Exchange Commission on March 12, 2020 (the “2019 Form 10-K”). The financial information as of September 30, 2020, and the three and nine months ended September 30, 2020 and 2019, respectively, is unaudited. In the opinion of management all adjustments, consisting only of normal recurring adjustments considered necessary for the fair presentation of financial position, results of operations, and cash flows at the dates and for the periods presented, have been included. The balance sheet data as of December 31, 2019 was derived from audited consolidated financial statements. The results of the Company’s operations for any interim periods are not necessarily indicative of the results that may be expected for any other interim period or for a full fiscal year. Based on its current operating plan, and not including additional access to capital that may become available under the Company’s credit facility, the Company believes that its cash, cash equivalents, and marketable securities as of September 30, 2020, will be sufficient to fund currently anticipated operating expenses through the end of 2022, including potential new drug application (NDA) submissions for reproxalap in dry eye disease and allergic conjunctivitis, assuming positive clinical trial results and regulatory review; the Phase 2 clinical trials of ADX-629 in COVID-19, atopic asthma, and psoriasis; and the continuation of Part 1 of the adaptive Phase 3 GUARD trial in proliferative vitreoretinopathy, contingent on patient enrollment. 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 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. In addition, the disruption in the capital markets caused by the COVID-19 outbreak could make any financing more challenging, and there can be no assurance that Aldeyra will be able to obtain such financing on commercially reasonable terms or at all. 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 financial statements in conformity with GAAP requires management to make estimates and assumptions, including fair value estimates for investments that affect the reported amounts of assets and 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 periods. The Company’s management evaluates its estimates and assumptions on an ongoing basis. Management’s most significant estimates in the Company’s consolidated financial statements include, but are not limited to, estimates related to clinical trial accruals, estimates related to prepaid and accrued research and development costs, acquired in-process research and development (“IPR&D”) expense, contingent liabilities, and accounting for income taxes and related valuation allowance. Although these estimates and assumptions are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Summary of Significant Accounting Policies There were no changes to significant accounting policies during the nine months ended September 30, 2020, as compared to the those identified in the 2019 Form 10-K. Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Helio Vision Acquisition	3. Helio Vision Acquisition On January 28, 2019 (the “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, 67% are vested as of September 30, 2020. The Company recognizes the expense associated with the founders’ restricted shares as research and development compensation expense on a straight-line basis as the shares vest over the three-year 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) $2.5 million of common stock on the date that is 24 months following the Closing Date (assuming certain technical milestones are met); (b) $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 (c) $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) – (c) 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 September 30, 2020. 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. No milestones related to the Milestone Shares are probable of being achieved as of September 30, 2020. The Company assessed the acquisition of Helio under the FASB ASC Topic 805, Business Combinations ( “ ASC 805 ” ). Under ASC 805, the Company determined that the acquired assets did not constitute a business since substantially all the assets acquired were related to ADX-2191 and that the transaction would be accounted for as an asset acquisition. The asset and development program acquired from Helio are at an early stage of development and will require a significant investment of time and capital for development. There is no assurance that the Company will be successful in developing such asset, and a failure to successfully develop such asset could diminish the Company’s prospects. Under ASC 805, the asset acquired is considered to have no alternative future uses, since the future economic benefit of the acquired asset at the date of acquisition is highly uncertain. The fair value of the assets was determined using the quoted market price of the Company’s common stock on the C losing D ate and was fully expensed as IPR&D . Additionally, the Company assessed the Helio acquisition under ASC Topic 740, Income Taxes ( “ ASC 740 ” ). The acquisition resulted in an income tax benefit of $ 1.3 million and a corresponding increase to acquired IPR&D expense. The expense resulted from the reduction in the Company’s valuation allowance due to the deferred tax liability created as a result of the book and tax basis difference during the quarter ended March 3 1 , 2019 . During the nine months ended September 30, 20 19 , the Company recorded $ million of IPR&D expense related to the fair value of consideration given which includes transaction costs and the deferred tax impact of the Helio acquisition .

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	4. NET LOSS PER SHARE As of September 30, 2020 and 2019, 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: Three and Nine Months Ended September 30, 2020 2019 Options to purchase common stock 4,889,685 4,539,279 Restricted stock units 929,817 430,425 Nonvested founder shares (1) 188,638 426,472 Total of common stock equivalents 6,008,140 5,396,176 (1) Represents 188,638 shares of common stock that are issued and outstanding but that were subject to vesting based on service requirements at September 30, 2020 and are not included in stockholders’ equity pursuant to GAAP.

Cash, Cash Equivalents and Mark

Cash, Cash Equivalents and Marketable Securities	9 Months Ended
	Sep. 30, 2020
Cash And Cash Equivalents [Abstract]
Cash, Cash Equivalents and Marketable Securities	5. CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES Cash, cash equivalents, and marketable securities were comprised of: September 30, 2020 Carrying Amount Unrecognized Gain Unrecognized Loss Estimated Fair Value Cash and Cash Equivalents Current Marketable Securities Cash $ 31,815,216 $ — $ — $ 31,815,216 $ 31,815,216 $ — Money market funds 39,360,291 — — 39,360,291 39,360,291 — Reverse repurchase agreements 15,000,000 — — 15,000,000 15,000,000 — Total Cash and cash equivalents 86,175,507 — — 86,175,507 86,175,507 — Total Cash, cash equivalents, and current marketable securities $ 86,175,507 $ — December 31, 2019 Carrying Amount Unrecognized Gain Unrecognized Loss Estimated Fair Value Cash and Cash Equivalents Current Marketable Securities Cash $ 15,363,462 $ — $ — $ 15,363,462 $ 15,363,462 $ — Money market funds 1,062,368 — — 1,062,368 1,062,368 — Reverse repurchase agreements 28,000,000 — — 28,000,000 28,000,000 — Total Cash and cash equivalents 44,425,830 — — 44,425,830 44,425,830 — U.S. government agency securities 28,932,679 5,866 — 28,938,545 — 28,938,545 Available for Sale (1) 28,932,679 5,866 — 28,938,545 — 28,938,545 Total Cash, cash equivalents and current marketable securities $ 44,425,830 $ 28,938,545 (1) Available for sale securities are reported at fair value with unrealized gains and losses reported net of taxes, if material, in other comprehensive income.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
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 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. There were no liabilities measured at fair value at September 30, 2020 or December 31, 2019. Money market funds included in cash and cash equivalents in the consolidated balance sheets, are recorded at fair value and considered as Level 1 inputs under the fair value hierarchy. Reverse repurchase agreements and U.S. government agency securities are recorded at fair market value and considered as Level 2 inputs under the fair value hierarchy. Financial instruments including cash equivalents, clinical trial prepayments to contract research organizations, and accounts payable are carried in the consolidated financial statements at amounts that approximate their fair value based on the short maturities of those instruments. The carrying amount of the Company’s term loan under its credit facility approximates market rates currently available to the Company.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	7. ACCRUED EXPENSES Accrued expenses were comprised of: September 30, December 31, 2020 2019 Accrued compensation $ 1,328,475 $ 1,489,475 Accrued research and development 1,960,150 9,493,093 Accrued general and administrative 730,010 890,554 Accrued expenses $ 4,018,635 $ 11,873,122

Credit Facility

Credit Facility	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Credit Facility	8. 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 (the “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 The term loan bears interest at an annual rate equal to the greater of (i) 9.10% and (ii) the prime rate (as reported in the Wall Street Journal or any successor publication thereto) plus 3.10%. The Loan and Security Agreement provides for interest-only payments until May 1, 2021, with an option to extend the interest-only period to May 1, 2022 based upon the achievement of certain milestones. Repayment of the aggregate outstanding principal balance of the term loan, in monthly installments, starts upon expiration of the interest-only period and continues through October 1, 2023 (the “Maturity Date”). 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 (the “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 through the Maturity Date using the effective interest method. The effective interest rate was 12.9% at September 30, 2020. 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 the following percentage of the principal amount being prepaid: 3% if the term loan is prepaid prior to March 25, 2021 and 1.5% if the term loan is prepaid any time thereafter, but prior to March 25, 2022. Long-term debt consisted of the following: September 30, December 31, 2020 2019 Term loan payable $ 15,000,000 $ 15,000,000 End of term charge 356,372 89,094 Unamortized debt issuance costs (403,644 ) (560,881 ) Less: current portion (2,259,417 ) — Total long-term debt $ 12,693,311 $ 14,528,212 Future principal payments, including the End of Term Charge, are as follows: Years Ending December 31, 2020 $ — 2021 3,659,776 2022 5,931,718 2023 6,451,006 Total $ 16,042,500 The Loan and Security Agreement also contains certain events of default, representations, warranties and non-financial covenants of the Company. In addition, subject to the terms of the 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	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders Equity	9. In December 2018, the Company entered into an Open Market Sales Agreement SM at a volume-weighted average price of $4.62 per share, As of September 30, 2020, the Company had sold the maximum allowable amount and no further sales may be made under the Jefferies Sales Agreement.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10. INCOME TAXES No provision for federal and state income taxes has 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. 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 net operating losses (“NOLs”) and certain other tax assets (tax attributes) 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, within the testing period 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. As of September 30, 2020, the Company believes four ownership changes have occurred since inception. The Company believes “Built-In Gains” will offset the majority of the Section 382 limitations generated by these ownership changes , including the most recent ownership change occurring in July 2020. However, the Company estimates that approximately $ 9 million of deferred tax assets related to NOLs and tax credits will be permanently limited as a result of the July 2020 ownership change. As a result of the Company’s full valuation allowance, there is no current period impact to the income statement. Any future ownership changes, including those resulting from the Company’s recent or future financing activities, may cause the Company’s existing tax attributes to incur additional limitations. All tax years are open for examination by the taxing authorities for both federal and state purposes. 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. Accordingly, in the provision for income taxes, the Company recognizes interest accrued related to unrecognized tax benefits and penalties; however, management is currently unaware of any uncertain tax positions. 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, accordingly these NOL and other benefit provisions have no impact on the Company’s financial statements for the period ended September 30, 2020.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11. STOCK-BASED COMPENSATION The Company has two equity incentive plans that provide 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 with a generally prescribed contractual term of ten years. 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 and Helio founders’ shares are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development expenses $ 1,236,902 $ 1,247,655 $ 3,429,592 $ 3,528,750 General and administrative expenses 520,577 905,283 $ 2,023,928 $ 2,605,240 Total stock-based compensation expense $ 1,757,479 $ 2,152,938 $ 5,453,520 $ 6,133,990 Stock Options The table below summarizes activity relating to stock options under the incentive plans for the nine months ended September 30, 2020: Number of Shares Weighted Average Exercise Price Weighted Average Contractual Term Aggregate Intrinsic Value(a) Outstanding at December 31, 2019 4,193,814 $ 6.62 Granted 1,669,023 $ 3.91 Exercised (219,244 ) $ 4.83 Expired (75,838 ) $ 6.72 Forfeitures (678,070 ) $ 6.53 Outstanding at September 30, 2020 4,889,685 $ 5.79 7.49 $ 9,439,040 Exercisable at September 30, 2020 2,745,371 $ 5.95 6.38 $ 4,924,800 (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 September 30, 2020 of $7.41 and the per share exercise price of the underlying options. As of September 30, 2020, unamortized stock-based compensation for all stock options outstanding was $7,478,325 and is expected to be recognized over a weighted average period of 2.30 years. Total unrecognized compensation cost will be adjusted for future forfeitures, if necessary. Restricted Stock Units The table below summarizes activity relating to RSUs for the nine months ended September 30, 2020: Number of Shares Outstanding at December 31, 2019 430,425 Granted 635,188 Vested/released (135,796 ) Outstanding at September 30, 2020 929,817 The weighted-average fair value of RSUs granted was $3.78 per share for the nine months ended September 30, 2020. As of September 30, 2020, the outstanding RSUs had unamortized stock-based compensation of $3.6 million with a weighted-average remaining recognition period of 2.69 years and an aggregate intrinsic value of $4.5 million. Employee Stock Purchase Plan At September 30, 2020, the Company had 857,446 shares available for issuance under the 2016 Employee Stock Purchase Plan (“2016 ESPP”). A summary of the weighted-average grant-date fair value, and total stock-based compensation expense recognized related to the 2016 ESPP are as follows: Nine Months Ended September 30, 2020 2019 Weighted-average grant-date fair value per share $ 1.58 $ 2.92 Total stock-based compensation expense $ 37,604 $ 76,507

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	1 2 . 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. As of September 30, 2020, the Company maintained an unamortized Right-Of-Use asset with a corresponding operating lease liability of approximately $58.7 thousand based on the present value of the minimum rental payments as a result of adoption of ASC Topic 842, Leases 2020 remaining total lease payments $ 59,613 Less: effect of discounting (893 ) Present value of lease liabilities $ 58,720 Current operating lease liabilities $ 58,720 Non-current operating lease liabilities — Total $ 58,720 The Company’s gross future minimum payments under all non-cancelable operating leases as of September 30, 2020 , are: Total 2020 2021 2022 2023 Operating lease obligations $ 59,613 $ 59,613 $ — $ — $ — In October 2020, the Company entered into a lease amendment extending the lease by 1 year through December 31, 2021 with rent payments totaling $243,126 during that 12-month period.

Legal Proceedings

Legal Proceedings	9 Months Ended
	Sep. 30, 2020
Legal Proceedings [Abstract]
Legal Proceedings	1 3 . LEGAL PROCEEDINGS In the ordinary course of its business, the Company may be involved in various legal proceedings involving contractual and employment relationships, patent or other intellectual property rights, and a variety of other matters. The Company is not aware of any pending legal proceedings that would reasonably be expected to have a material impact on the Company’s financial position or results of operations

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 4 . COMMITMENTS AND CONTINGENCIES There have been no material changes to the Company’s commitments and contingencies from the information provided in Note 13, Commitments and Contingencies

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions, including fair value estimates for investments that affect the reported amounts of assets and 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 periods. The Company’s management evaluates its estimates and assumptions on an ongoing basis. Management’s most significant estimates in the Company’s consolidated financial statements include, but are not limited to, estimates related to clinical trial accruals, estimates related to prepaid and accrued research and development costs, acquired in-process research and development (“IPR&D”) expense, contingent liabilities, and accounting for income taxes and related valuation allowance. Although these estimates and assumptions are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies There were no changes to significant accounting policies during the nine months ended September 30, 2020, as compared to the those identified in the 2019 Form 10-K.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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)	9 Months Ended
	Sep. 30, 2020
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: Three and Nine Months Ended September 30, 2020 2019 Options to purchase common stock 4,889,685 4,539,279 Restricted stock units 929,817 430,425 Nonvested founder shares (1) 188,638 426,472 Total of common stock equivalents 6,008,140 5,396,176 (1) Represents 188,638 shares of common stock that are issued and outstanding but that were subject to vesting based on service requirements at September 30, 2020 and are not included in stockholders’ equity pursuant to GAAP.

Cash, Cash Equivalents and Ma_2

Cash, Cash Equivalents and Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Cash And Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents and Marketable Securities	Cash, cash equivalents, and marketable securities were comprised of: September 30, 2020 Carrying Amount Unrecognized Gain Unrecognized Loss Estimated Fair Value Cash and Cash Equivalents Current Marketable Securities Cash $ 31,815,216 $ — $ — $ 31,815,216 $ 31,815,216 $ — Money market funds 39,360,291 — — 39,360,291 39,360,291 — Reverse repurchase agreements 15,000,000 — — 15,000,000 15,000,000 — Total Cash and cash equivalents 86,175,507 — — 86,175,507 86,175,507 — Total Cash, cash equivalents, and current marketable securities $ 86,175,507 $ — December 31, 2019 Carrying Amount Unrecognized Gain Unrecognized Loss Estimated Fair Value Cash and Cash Equivalents Current Marketable Securities Cash $ 15,363,462 $ — $ — $ 15,363,462 $ 15,363,462 $ — Money market funds 1,062,368 — — 1,062,368 1,062,368 — Reverse repurchase agreements 28,000,000 — — 28,000,000 28,000,000 — Total Cash and cash equivalents 44,425,830 — — 44,425,830 44,425,830 — U.S. government agency securities 28,932,679 5,866 — 28,938,545 — 28,938,545 Available for Sale (1) 28,932,679 5,866 — 28,938,545 — 28,938,545 Total Cash, cash equivalents and current marketable securities $ 44,425,830 $ 28,938,545 (1) Available for sale securities are reported at fair value with unrealized gains and losses reported net of taxes, if material, in other comprehensive income.

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses were comprised of: September 30, December 31, 2020 2019 Accrued compensation $ 1,328,475 $ 1,489,475 Accrued research and development 1,960,150 9,493,093 Accrued general and administrative 730,010 890,554 Accrued expenses $ 4,018,635 $ 11,873,122

Credit Facility (Tables)

Credit Facility (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	Long-term debt consisted of the following: September 30, December 31, 2020 2019 Term loan payable $ 15,000,000 $ 15,000,000 End of term charge 356,372 89,094 Unamortized debt issuance costs (403,644 ) (560,881 ) Less: current portion (2,259,417 ) — Total long-term debt $ 12,693,311 $ 14,528,212
Schedule of Principal Payments Including End of Term Charges	Future principal payments, including the End of Term Charge, are as follows: Years Ending December 31, 2020 $ — 2021 3,659,776 2022 5,931,718 2023 6,451,006 Total $ 16,042,500

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
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 and Helio founders’ shares are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development expenses $ 1,236,902 $ 1,247,655 $ 3,429,592 $ 3,528,750 General and administrative expenses 520,577 905,283 $ 2,023,928 $ 2,605,240 Total stock-based compensation expense $ 1,757,479 $ 2,152,938 $ 5,453,520 $ 6,133,990
Summary of Activity Relating to Stock Options	The table below summarizes activity relating to stock options under the incentive plans for the nine months ended September 30, 2020: Number of Shares Weighted Average Exercise Price Weighted Average Contractual Term Aggregate Intrinsic Value(a) Outstanding at December 31, 2019 4,193,814 $ 6.62 Granted 1,669,023 $ 3.91 Exercised (219,244 ) $ 4.83 Expired (75,838 ) $ 6.72 Forfeitures (678,070 ) $ 6.53 Outstanding at September 30, 2020 4,889,685 $ 5.79 7.49 $ 9,439,040 Exercisable at September 30, 2020 2,745,371 $ 5.95 6.38 $ 4,924,800 (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 September 30, 2020 of $7.41 and the per share exercise price of the underlying options.
Summary of Activity Relating to Restricted Stock Units	The table below summarizes activity relating to RSUs for the nine months ended September 30, 2020: Number of Shares Outstanding at December 31, 2019 430,425 Granted 635,188 Vested/released (135,796 ) Outstanding at September 30, 2020 929,817
Summary of Employee Stock Purchase Plan Activity	A summary of the weighted-average grant-date fair value, and total stock-based compensation expense recognized related to the 2016 ESPP are as follows Nine Months Ended September 30, 2020 2019 Weighted-average grant-date fair value per share $ 1.58 $ 2.92 Total stock-based compensation expense $ 37,604 $ 76,507

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 is as follows: 2020 remaining total lease payments $ 59,613 Less: effect of discounting (893 ) Present value of lease liabilities $ 58,720 Current operating lease liabilities $ 58,720 Non-current operating lease liabilities — Total $ 58,720 The Company’s gross future minimum payments under all non-cancelable operating leases as of September 30, 2020 , are: Total 2020 2021 2022 2023 Operating lease obligations $ 59,613 $ 59,613 $ — $ — $ —

Helio Vision Acquisition - Addi

Helio Vision Acquisition - Additional Information (Detail) - USD ($)	Jan. 28, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Acquisition [Line Items]
Income tax benefit				$ 1,309,973
Acquired in-process research and development				$ 6,500,602
Helio Vision Inc
Business Acquisition [Line Items]
Business combination, stock issued	1,160,444
Income tax benefit		$ 1,300,000
Acquired in-process research and development			$ 6,500,000
Helio Vision Inc | Founders [Member]
Business Acquisition [Line Items]
Business combination, stock issued	568,627
Helio Vision Inc | Founders [Member] | Service Based Awards [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	67.00%
Helio Vision Inc | Founders [Member] | Restricted Stock [Member]
Business Acquisition [Line Items]
Share-based compensation award, vesting period	3 years
Helio Vision Inc | Non Founders [Member]
Business Acquisition [Line Items]
Business combination, stock issued	591,817
Helio Vision Inc | Common Stock, 24 Months Following the Closing Date [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration liability	$ 2,500,000
Helio Vision Inc | Common Stock after FDA Approval prior to 10th Anniversary [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration liability	10,000,000
Helio Vision Inc | Common Stock after FDA Approval Prior to 12th Anniversary [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration liability	$ 2,500,000
Helio Vision Inc | Common Stock after FDA Approval Prior to 12th Anniversary [Member] | Maximum [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration stock to be issued	5,248,885
Helio Vision Inc | Tax Gross-up Payment in Event of Change of Control or Divesture [Member] | Maximum [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration liability	$ 1,000,000

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Diluted Weighted-Average Shares Outstanding (Detail) - shares		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents		6,008,140	5,396,176	6,008,140	5,396,176
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents		4,889,685	4,539,279	4,889,685	4,539,279
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents		929,817	430,425	929,817	430,425
Nonvested Founder Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of common stock equivalents	[1]	188,638	426,472	188,638	426,472
[1]	Represents 188,638 shares of common stock that are issued and outstanding but that were subject to vesting based on service requirements at September 30, 2020 and are not included in stockholders’ equity pursuant to GAAP.

Net Loss Per Share - Computat_2

Net Loss Per Share - Computation of Diluted Weighted-Average Shares Outstanding (Parenthetical) (Detail)	Sep. 30, 2020shares
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	188,638

Cash, Cash Equivalents and Ma_3

Cash, Cash Equivalents and Marketable Securities - Schedule of Cash, Cash Equivalents and Marketable Securities (Detail) - USD ($)		Sep. 30, 2020	Dec. 31, 2019
Cash Cash Equivalents And Marketable Securities [Line Items]
Cash		$ 31,815,216	$ 15,363,462
Money market funds		39,360,291	1,062,368
Reverse repurchase agreements		15,000,000	28,000,000
Total Cash and cash equivalents		86,175,507	44,425,830
U.S. government agency securities			28,932,679
Available for Sale	[1]		28,932,679
Cash and Cash Equivalents		86,175,507	44,425,830
Current Marketable Securities			28,938,545
Available for Sale [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Unrecognized Gain	[1]		5,866
Estimated Fair Value	[1]		28,938,545
Current Marketable Securities	[1]		28,938,545
Cash [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value		31,815,216	15,363,462
Cash and Cash Equivalents		31,815,216	15,363,462
Money Market Funds [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value		39,360,291	1,062,368
Cash and Cash Equivalents		39,360,291	1,062,368
Reverse Repurchase Agreements [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value		15,000,000	28,000,000
Cash and Cash Equivalents		15,000,000	28,000,000
U.S. Government Agencies Securities [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Unrecognized Gain			5,866
Estimated Fair Value			28,938,545
Current Marketable Securities			28,938,545
Total Cash and cash equivalents [Member]
Cash Cash Equivalents And Marketable Securities [Line Items]
Estimated Fair Value		86,175,507	44,425,830
Cash and Cash Equivalents		$ 86,175,507	$ 44,425,830
[1]	Available for sale securities are reported at fair value with unrealized gains and losses reported net of taxes, if material, in other comprehensive income.

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Liabilities measured at fair value on a recurring basis	$ 0	$ 0

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued compensation	$ 1,328,475	$ 1,489,475
Accrued research and development	1,960,150	9,493,093
Accrued general and administrative	730,010	890,554
Accrued expenses	$ 4,018,635	$ 11,873,122

Credit Facility - Additional In

Credit Facility - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Line Of Credit Facility [Line Items]
Proceeds from Long-term lines of credit		$ 16,042,500
Debt instrument annual interest rate	9.10%
Interest payment period	May 1, 2021
Interest payment extension period	May 1, 2022
Term loan maturity date	Oct. 1, 2023
Credit facility fee	$ 375,000
Credit facility commitment fee percentage	6.95%
Term loan prepayment term	3% if the term loan is prepaid prior to March 25, 2021 and 1.5% if the term loan is prepaid any time thereafter, but prior to March 25, 2022
Commitment charge	$ 25,000
Transaction costs	$ 273,186
Credit facility, interest rate	12.90%
Maximum [Member]
Line Of Credit Facility [Line Items]
Credit facility prepayment fee percentage	3.00%
Minimum [Member]
Line Of Credit Facility [Line Items]
Credit facility prepayment fee percentage	1.50%
Prime Rate [Member]
Line Of Credit Facility [Line Items]
Debt instrument variable annual interest rate	3.10%
Hercules Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility amount	$ 60,000,000
Credit facility amount outstanding	15,000,000
Additional credit facility available for borrowing	0
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] | 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

Credit Facility - Schedule of L

Credit Facility - Schedule of Long-Term Debt (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Line Of Credit Facility [Abstract]
Term loan payable	$ 15,000,000	$ 15,000,000
End of term charge	356,372	89,094
Unamortized debt issuance costs	(403,644)	(560,881)
Less: current portion	(2,259,417)
Total long-term debt	$ 12,693,311	$ 14,528,212

Credit Facility - Schedule of P

Credit Facility - Schedule of Principal Payments Incuding End of Term Charges (Detail)	Dec. 31, 2019USD ($)
Line Of Credit Facility [Abstract]
2021	$ 3,659,776
2022	5,931,718
2023	6,451,006
Total	$ 16,042,500

Stockholders Equity - Additiona

Stockholders Equity - Additional Information (Details) - USD ($)	1 Months Ended	9 Months Ended
	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019
Class Of Stock [Line Items]
Proceeds from issuance of common stock, net of commissions and other offering costs		$ 40,716,543	$ 720,964
Jefferies LLC [Member] | Jefferies Sales Agreement [Member]
Class Of Stock [Line Items]
Volume-weighted average price		$ 4.62
Issuance of common stocks		9,351,749
Proceeds from issuance of common stock, net of commissions and other offering costs		$ 40,700,000
Jefferies LLC [Member] | Jefferies Sales Agreement [Member] | Maximum [Member]
Class Of Stock [Line Items]
Expected aggregate gross proceeds from issuance of stock	$ 50,000,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Income Tax [Line Items]
Provision for income tax benefit		$ (1,309,973)
Deferred tax assets valuation allowance	100.00%
Deferred tax asset related to NOLs and tax credits	$ 9,000,000
State and Federal [Member]
Income Tax [Line Items]
Provision for income tax benefit	$ 0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2020USD ($)NumberofPlan$ / sharesshares	Sep. 30, 2019$ / shares
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation	$ 7,478,325
Weighted average recognition period	2 years 3 months 18 days
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation	$ 3,600,000
Weighted average grant date fair value | $ / shares	$ 3.78
Weighted average remaining recognition period	2 years 8 months 8 days
Aggregate intrinsic value of options outstanding	$ 4,500,000
Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans | NumberofPlan	2
Equity incentive plans, contractual term	ten years
Common stock available for issuance | shares	940,863
2016 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance | shares	857,446
Weighted average grant date fair value | $ / shares	$ 1.58	$ 2.92

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 1,757,479	$ 2,152,938	$ 5,453,520	$ 6,133,990
Research and Development Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	1,236,902	1,247,655	3,429,592	3,528,750
General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 520,577	$ 905,283	$ 2,023,928	$ 2,605,240

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($)		9 Months Ended
		Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares Outstanding, Beginning Balance		4,193,814
Number of Shares, Granted		1,669,023
Number of Shares, Exercised		(219,244)
Number of Shares, Expired		(75,838)
Number of Shares, Forfeitures		(678,070)
Number of Shares Outstanding, Ending Balance		4,889,685
Number of Shares Exercisable, Ending Balance		2,745,371
Weighted Average Exercise Price, Beginning Balance		$ 6.62
Weighted Average Exercise Price, Granted		3.91
Weighted Average Exercise Price, Exercised		4.83
Weighted Average Exercise Price, Expired		6.72
Weighted Average Exercise Price, Forfeitures		6.53
Weighted Average Exercise Price, Ending Balance		5.79
Weighted Average Exercise Price Exercisable, Ending Balance		$ 5.95
Weighted Average Contractual Term, Outstanding		7 years 5 months 26 days
Weighted Average Contractual Term, Exercisable		6 years 4 months 17 days
Aggregate Intrinsic Value, Outstanding	[1]	$ 9,439,040
Aggregate Intrinsic Value, Exercisable	[1]	$ 4,924,800
[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 September 30, 2020 of $7.41 and the per share exercise price of the underlying options.

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Parenthetical) (Detail)	Sep. 30, 2020$ / shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Closing market value of common stock	$ 7.41

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Activity Relating to Restricted Stock Units (Detail) - Restricted Stock Units (RSUs) [Member]	9 Months Ended
	Sep. 30, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Outstanding, Beginning Balance	430,425
Granted	635,188
Vested/released	(135,796)
Number of Shares Outstanding, Ending Balance	929,817

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Employee Stock Purchase Plan Activity (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,757,479	$ 2,152,938	$ 5,453,520	$ 6,133,990
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			$ 1.58	$ 2.92
Total stock-based compensation expense			$ 37,604	$ 76,507

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($)	1 Months Ended	9 Months Ended
	Oct. 31, 2020	Sep. 30, 2020
Operating Leased Assets [Line Items]
Operating lease liability		$ 58,720
Operating leases, weighted average remaining lease term (years)		3 months
Operating leases, weighted average discount rate		9.10%
Operating lease, expense		$ 200,000
Subsequent Event [Member]
Operating Leased Assets [Line Items]
Lease extended term	1 year
Operating lease rent payments	$ 243,126

Leases - Schedule of Maturities

Leases - Schedule of Maturities and Balance Sheet Presentation of Lease Liabilities (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Leases [Abstract]
2020 remaining total lease payments	$ 59,613
Less: effect of discounting	(893)
Present value of lease liabilities	58,720
Current operating lease liabilities	58,720	$ 226,328
Non-current operating lease liabilities	0
Present value of lease liabilities	$ 58,720

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments Under Non-Cancelable Operating Leases (Detail)	Sep. 30, 2020USD ($)
Leases [Abstract]
2020 remaining total lease payments	$ 59,613
Operating lease obligations, 2020	$ 59,613