Acer Therapeutics (ACER) 10-Q 10 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 01, 2020
Cover [Abstract]
Entity Registrant Name	Acer Therapeutics Inc.
Entity Central Index Key	0001069308
Document Type	10-Q
Document Period End Date	Sep. 30, 2020
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Trading Symbol	ACER
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		12,285,005
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2020
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-33004
Entity Tax Identification Number	32-0426967
Entity Address, Address Line One	One Gateway Center
Entity Address, Address Line Two	Suite 351
Entity Address, Address Line Three	300 Washington Street
Entity Address, City or Town	Newton
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02458
City Area Code	844
Local Phone Number	902-6100
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Condensed Balance Sheets

Condensed Balance Sheets - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 6,157,448	$ 12,077,640
Prepaid expenses and other current assets	846,399	807,356
Total current assets	7,003,847	12,884,996
Property and equipment, net	143,145	193,974
Other assets:
Goodwill	7,647,267	7,647,267
In-process research and development	118,600	118,600
Other non-current assets	454,044	620,674
Total assets	15,366,903	21,465,511
Current liabilities:
Accounts payable	914,204	561,090
Accrued expenses	2,953,648	1,944,431
Other current liabilities	621,572	263,392
Total current liabilities	4,489,424	2,768,913
Other non-current liabilities	373,967	326,282
Total liabilities	4,863,391	3,095,195
Commitments and Contingencies (Note 6)
Stockholders’ equity:
Preferred stock, $0.0001 par value; authorized 10,000,000 shares; none issued and outstanding
Common stock, $0.0001 par value; authorized 150,000,000 shares; 11,912,731 and 10,095,176 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	1,192	1,010
Additional paid-in capital	103,400,598	94,619,818
Accumulated deficit	(92,898,278)	(76,250,512)
Total stockholders’ equity	10,503,512	18,370,316
Total liabilities and stockholders’ equity	$ 15,366,903	$ 21,465,511

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	11,912,731	10,095,176
Common stock, shares outstanding	11,912,731	10,095,176

Condensed Statements of Operati

Condensed Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development	$ 3,227,048	$ 2,828,787	$ 8,366,702	$ 11,021,251
General and administrative	2,661,989	2,533,678	8,263,677	13,683,852
Total operating expenses	5,889,037	5,362,465	16,630,379	24,705,103
Loss from operations	(5,889,037)	(5,362,465)	(16,630,379)	(24,705,103)
Other (expense) income, net:
Interest and other (expense) income, net	(4,129)	91,321	17,673	420,348
Foreign currency transaction (loss) gain	(35,092)	19,671	(35,059)	23,070
Total other (expense) income, net	(39,221)	110,992	(17,386)	443,418
Net loss	$ (5,928,258)	$ (5,251,473)	$ (16,647,765)	$ (24,261,685)
Net loss per share - basic and diluted	$ (0.51)	$ (0.52)	$ (1.56)	$ (2.40)
Weighted average common shares outstanding - basic and diluted	11,514,254	10,095,176	10,662,164	10,091,169

Condensed Statements of Changes

Condensed Statements of Changes in Stockholders' Equity - USD ($)	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ 45,083,158	$ 1,009	$ 91,914,692	$ (46,832,543)
Beginning balance, shares at Dec. 31, 2018		10,087,363
Stock-based compensation	671,927		671,927
Net loss	(7,968,705)			(7,968,705)
Ending balance at Mar. 31, 2019	37,786,380	$ 1,009	92,586,619	(54,801,248)
Ending balance, shares at Mar. 31, 2019		10,087,363
Beginning balance at Dec. 31, 2018	45,083,158	$ 1,009	91,914,692	(46,832,543)
Beginning balance, shares at Dec. 31, 2018		10,087,363
Net loss	(24,261,685)
Ending balance at Sep. 30, 2019	22,865,062	$ 1,010	93,958,280	(71,094,228)
Ending balance, shares at Sep. 30, 2019		10,095,176
Beginning balance at Mar. 31, 2019	37,786,380	$ 1,009	92,586,619	(54,801,248)
Beginning balance, shares at Mar. 31, 2019		10,087,363
Stock-based compensation	715,366		715,366
Issuance of stock in connection with stock option exercises	92,272	$ 1	92,271
Issuance of stock in connection with stock option exercises, shares		7,813
Net loss	(11,041,507)			(11,041,507)
Ending balance at Jun. 30, 2019	27,552,511	$ 1,010	93,394,256	(65,842,755)
Ending balance, shares at Jun. 30, 2019		10,095,176
Stock-based compensation	564,024		564,024
Net loss	(5,251,473)			(5,251,473)
Ending balance at Sep. 30, 2019	22,865,062	$ 1,010	93,958,280	(71,094,228)
Ending balance, shares at Sep. 30, 2019		10,095,176
Beginning balance at Dec. 31, 2019	$ 18,370,316	$ 1,010	94,619,818	(76,250,512)
Beginning balance, shares at Dec. 31, 2019	10,095,176	10,095,176
Issuance of common stock in connection with restricted stock unit vesting	$ 1	$ 1
Issuance of common stock in connection with restricted stock unit vesting, shares		5,858
Stock-based compensation	667,338		667,338
Net loss	(4,948,707)			(4,948,707)
Ending balance at Mar. 31, 2020	14,088,948	$ 1,011	95,287,156	(81,199,219)
Ending balance, shares at Mar. 31, 2020		10,101,034
Beginning balance at Dec. 31, 2019	$ 18,370,316	$ 1,010	94,619,818	(76,250,512)
Beginning balance, shares at Dec. 31, 2019	10,095,176	10,095,176
Net loss	$ (16,647,765)
Ending balance at Sep. 30, 2020	$ 10,503,512	$ 1,192	103,400,598	(92,898,278)
Ending balance, shares at Sep. 30, 2020	11,912,731	11,912,731
Beginning balance at Mar. 31, 2020	$ 14,088,948	$ 1,011	95,287,156	(81,199,219)
Beginning balance, shares at Mar. 31, 2020		10,101,034
Issuance of common stock through at-the-market facility, net of issuance costs	1,941,095	$ 36	1,941,059
Issuance of common stock through at-the-market facility, net of issuance costs, shares		363,549
Issuance of common stock for commitment fee	355,555	$ 15	355,540
Issuance of common stock for commitment fee, shares		148,148
Stock-based compensation	603,574		603,574
Net loss	(5,770,801)			(5,770,801)
Ending balance at Jun. 30, 2020	11,218,371	$ 1,062	98,187,329	(86,970,020)
Ending balance, shares at Jun. 30, 2020		10,612,731
Issuance of common stock through at-the-market facility, net of issuance costs	3,868,497	$ 105	3,868,392
Issuance of common stock through at-the-market facility, net of issuance costs, shares		1,055,002
Issuance of common stock through private placement	857,499	$ 25	857,474
Issuance of common stock through private placement, shares		244,998
Stock-based compensation	487,403		487,403
Net loss	(5,928,258)			(5,928,258)
Ending balance at Sep. 30, 2020	$ 10,503,512	$ 1,192	$ 103,400,598	$ (92,898,278)
Ending balance, shares at Sep. 30, 2020	11,912,731	11,912,731

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (16,647,765)	$ (24,261,685)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	1,758,315	1,951,317
Depreciation	53,058	40,573
Fair value of shares issued for commitment fee	355,555
Loss on disposal of property and equipment		57,578
Non-cash interest expense	2,297
Changes in operating assets and liabilities
Prepaid expenses and other current assets	(39,043)	102,957
Accounts payable	353,114	(1,004,260)
Accrued expenses and other current liabilities	1,016,936	(2,391,433)
Other non-current assets		(10,620)
Net cash used in operating activities	(13,147,533)	(25,515,573)
Cash flows from investing activities:
Purchase of property and equipment	(2,229)	(126,080)
Net cash used in investing activities	(2,229)	(126,080)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	6,667,091
Proceeds from Paycheck Protection Program loan	562,479
Proceeds from the exercise of stock options		92,272
Net cash provided by financing activities	7,229,570	92,272
Net decrease in cash and cash equivalents	(5,920,192)	(25,549,381)
Cash and cash equivalents, beginning of period	12,077,640	41,671,284
Cash and cash equivalents, end of period	$ 6,157,448	$ 16,121,903

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	1. NATURE OF OPERATIONS AND BASIS OF PRESENTATION Business Acer Therapeutics Inc., a Delaware corporation (the “Company”), is a pharmaceutical company focused on the acquisition, development, and commercialization of therapies for serious rare and life-threatening diseases with significant unmet medical needs. The Company’s pipeline includes four programs: emetine hydrochloride (“emetine”) for the treatment of patients with COVID-19; ACER-001 (a taste-masked, immediate release formulation of sodium phenylbutyrate) for the treatment of various inborn errors of metabolism, including urea cycle disorders (“UCD”) and Maple Syrup Urine Disease (“MSUD”); EDSIVO™ (celiprolol) for the treatment of vascular Ehlers-Danlos syndrome (“vEDS”) in patients with a confirmed type III collagen (COL3A1) mutation; and osanetant for the treatment of induced vasomotor symptoms (“iVMS”). The Company’s product candidates are believed to present a comparatively de-risked profile, having one or more of a favorable safety profile, clinical proof-of-concept data, mechanistic differentiation, and/or accelerated paths for development through specific programs and procedures established by the United States (“U.S.”) Food and Drug Administration (“FDA”). Since its inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, acquiring operating assets, and raising capital. The Company has not generated any product revenue to date and may never generate any product revenue in the future. Liquidity The Company had an accumulated deficit of $92.9 million and cash and cash equivalents of $6.2 million as of September 30, 2020. Net cash used in operating activities was $13.1 million and $25.5 million for the nine months ended September 30, 2020 and 2019, respectively. On November 9, 2018, the Company entered into a sales agreement with Roth Capital Partners, LLC, and on March 18, 2020, an amended and restated sales agreement was entered into with JonesTrading Institutional Services LLC and Roth Capital Partners, LLC. The agreement provides a facility for the offer and sale of shares of common stock from time to time having an aggregate offering price of up to $50 million depending upon market demand, in transactions deemed to be an at-the-market (“ATM”) offering. Any such sales would be effected pursuant to the Company’s registration statement on Form S-3 (File No. 333-228319), declared effective by the SEC on November 21, 2018 . On April 30, 2020, the Company entered into a purchase agreement and registration rights agreement pursuant to which Lincoln Park Capital Fund, LLC (“Lincoln Park”) has committed to purchase up to $15.0 million of the Company’s common stock. Under the terms and subject to the conditions of the purchase agreement, the Company has the right, but not the obligation, to sell to Lincoln Park, and Lincoln Park is obligated to purchase up to $15.0 million of the Company’s common stock. Such sales of common stock by the Company will be subject to certain limitations, and may occur from time to time, at the Company’s sole discretion, over the 36-month period commencing on June 8, 2020. The number of shares the Company may sell to Lincoln Park on any single business day in a regular purchase is 50,000, but that amount may be increased up to 100,000 shares, depending upon the market price of the Company’s common stock at the time of sale and subject to a maximum limit of $1.0 million per regular purchase. The purchase price per share for each such regular purchase will be based on prevailing market prices of the Company’s common stock immediately preceding the time of sale as computed under the purchase agreement. In addition to regular purchases, the Company may also direct Lincoln Park to purchase other amounts as accelerated purchases or as additional accelerated purchases if the closing sale price of the common stock exceeds certain threshold prices as set forth in the purchase agreement. The Company issued 148,148 shares of common stock to Lincoln Park as a commitment fee in connection with entering into the purchase agreement. The $0.4 million fair value of the commitment fee shares was recorded to General and administrative expense along with other costs incurred in connection with entering into the purchase agreement. On July 24, 2020, the Company entered into a securities purchase agreement for the sale and issuance of an aggregate of 244,998 shares of the Company’s common stock, for an aggregate purchase price of $0.9 million, in a private placement transaction (“Private Placement”) with certain directors, officers, and employees at a price per share of $3.50. The shares of common stock issued in the Private Placement constitute “restricted securities” under the federal securities laws and are subject to a minimum six-month holding period. The Company’s existing cash and cash equivalents available at September 30, 2020, combined with the funds raised subsequent to September 30, 2020 via the ATM and equity line, are expected to fund operations into the first quarter of 2021 and enable it to advance emetine toward Investigational New Drug Application (“IND”) submission, continue to advance ACER-001 toward New Drug Application (“NDA”) submission, submit a plan with respect to EDSIVO TM Management expects to continue to finance operations through the issuance of additional equity or debt securities, non-dilutive funding, and/or through strategic collaborations. Any transactions which occur may contain covenants that restrict the ability of management to operate the business and any securities issued may have rights, preferences, or privileges senior to the Company’s common stock and may dilute the ownership of current stockholders of the Company. Going Concern The accompanying financial statements have been prepared in conformity with GAAP, which contemplate continuation of the Company as a going concern. The Company has not established a source of revenues and, as such, has been dependent on funding operations through the sale of equity securities. Since inception, the Company has experienced significant losses and incurred negative cash flows from operations. The Company has an accumulated deficit of $92.9 million as of September 30, 2020 and expects to incur further losses over the next several years as it develops its business. The Company has spent, and expects to continue to spend, a substantial amount of funds in connection with implementing its business strategy, including its planned product development efforts and potential precommercial activities. As of September 30, 2020, the Company had cash and cash equivalents of $6.2 million and current liabilities of $4.5 million. The Company’s cash and cash equivalents available at September 30, 2020, combined with the funds raised subsequent to September 30, 2020 via the ATM and equity line, are expected to fund operations into the first quarter of 2021, excluding support for a planned emetine Phase 2/3 clinical trial, which is also subject to ongoing discussions with the FDA. The Company will need to raise additional capital to fund continued operations in 2021. The Company may not be successful in its efforts to raise additional funds or achieve profitable operations. The Company continues to explore potential opportunities and alternatives to obtain the additional resources that will be necessary to support its ongoing operations through and beyond the next 12 months, including raising additional capital through either private or public equity or debt financing or non-dilutive funding, as well as using its ATM facility and/or its $15.0 million equity line facility entered into on April 30, 2020 with Lincoln Park, which is subject to certain limitations and conditions. The Company has no commitments for any additional financing, except for the agreement with Lincoln Park. Any amounts raised will be used for further development of its product candidates, precommercial activities, potential acquisitions of additional product candidates, and for other working capital purposes. If the Company is unable to obtain additional funding to support its current or proposed activities and operations, it may not be able to continue its operations as proposed, which may require it to suspend or terminate any ongoing development activities, modify its business plan, curtail various aspects of its operations, cease operations, or seek relief under applicable bankruptcy laws. In such event, the Company’s stockholders may lose a substantial portion or even all of their investment. These factors individually and collectively raise substantial doubt about the Company’s ability to continue as a going concern for twelve months from the date these financial statements are available, or November 10, 2020. The accompanying unaudited condensed financial statements do not include any adjustments or classifications that may result from the possible inability of the Company to continue as a going concern. Merger and Reincorporation On September 19, 2017, the Company (then a Texas corporation known as Opexa Therapeutics, Inc.) completed its business combination with Acer Therapeutics Inc., a Delaware corporation (“Private Acer”), in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of June 30, 2017, by and among the Company, Opexa Merger Sub, Inc. (“Merger Sub”) and Private Acer, pursuant to which Merger Sub merged with and into Private Acer, with Private Acer surviving as a wholly-owned subsidiary of the Company (the “Merger”). Immediately following the Merger, the Company changed its name to “Acer Therapeutics Inc.” pursuant to amendments to its certificate of formation filed with the Texas Secretary of State on September 19, 2017. Following the completion of the Merger, the business conducted by the Company became primarily the business conducted by Private Acer. For accounting and financial reporting purposes, Private Acer was considered to have acquired the Company in the Merger. On May 15, 2018, the Company changed its state of incorporation from the State of Texas to the State of Delaware pursuant to a plan of conversion, dated May 15, 2018. Immediately following the reincorporation, the holding company structure was eliminated by merging wholly-owned subsidiary Private Acer with and into the Company. The Company was the surviving corporation in connection with the subsidiary merger. Basis of Presentation The accompanying unaudited condensed financial statements are unaudited and have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Regulation S-X. The unaudited condensed financial statements have been prepared on the same basis as the audited annual financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial position, results of operations, stockholders’ equity and cash flows for the periods presented. The results of operations for the three and nine months ended September 30, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any other future annual or interim period. The condensed balance sheet as of December 31, 2019, included herein, was derived from the audited financial statements as of that date but does not include all disclosures required by GAAP. These unaudited financial state Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Significant Accounting Polices

Significant Accounting Polices	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Significant Accounting Polices	2. SIGNIFICANT ACCOUNTING POLICIES The Company’s significant accounting policies are described in Note 2, “Significant Accounting Policies,” in its Annual Report on Form 10-K for the year ended December 31, 2019. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less at the date of purchase to be cash equivalents. The Company follows the provisions of ASC Topic 820, Fair Value Measurement, which establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The Company considers its investments in money market funds of $5.7 million and $11.6 million as of September 30, 2020 and December 31, 2019, respectively, included in cash and cash equivalents, to be Level 1, which are based on unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. The estimated fair value of the Company’s financial instruments, which include cash and cash equivalents, accounts payable, and accrued liabilities approximates their carrying value, based upon their short-term maturities or prevailing interest rates. Goodwill Goodwill represents the excess of the purchase price (consideration paid plus net liabilities assumed) of an acquired business over the fair value of the underlying net tangible and intangible assets. The Company evaluates the recoverability of goodwill according to ASU No. 2017-04, Intangibles – Goodwill and Other a respiratory illness caused by a novel coronavirus Stock-Based Compensation The Company records stock-based payments at fair value. The measurement date for compensation expense related to awards is generally the date of the grant. The fair value of awards is recognized as an expense in the condensed statement of operations over the requisite service period, which is generally the vesting period. The fair value of options is calculated using the Black-Scholes option pricing model. This option valuation model requires the use of assumptions including, among others, the volatility of stock price, the expected term of the option, and the risk-free interest rate. The following assumptions were used to estimate the fair value of stock options granted during the nine months ended September 30, 2020 and 2019 using the Black-Scholes option pricing model: 2020 2019 Risk-free interest rate 0.36% – 1.61% 1.68% – 2.57% Expected life (years) 6.25 6.25 Volatility 60% 60% Dividend rate 0% 0% Use of Estimates The Company’s accounting principles require management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of assets and liabilities at the date of the condensed financial statements and reported amounts of revenues and expenses during the reporting period. Estimates having relatively higher significance include stock-based compensation, contract manufacturing accruals, and income taxes. Actual results could differ from those estimates and changes in estimates may occur. Income Taxes The Company recorded no income tax expense or benefit during the three and nine months ended September 30, 2020 and 2019, due to a full valuation allowance recognized against its net deferred tax assets. The Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was enacted in the U.S. on March 27, 2020 . The CARES Act, among other things, includes provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations, increased limitations on qualified charitable contributions, and technical corrections to tax depreciation methods for qualified improvement property. The Company is required to recognize the effects of tax law changes in the period of enactment. The enactment of the CARES Act did not result in material adjustments for the income tax provision for the three and nine months ended or to the Company’s assessment of the realizability of deferred tax assets as the carry back of net operating losses was used as a source of income. There were no other effects to the Company’s tax provision as a result of the CARES Act as of September 30, 2020. Basic and Diluted Net Loss per Common Share Basic and diluted net loss per common share is computed by dividing net loss in each period by the weighted average number of shares of common stock outstanding during such period. For the periods presented, common stock equivalents, consisting of stock-based awards, were not included in the calculation of the diluted loss per share because to do so would be anti-dilutive. Recent Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other Options The amendments of this ASU are effective for fiscal years beginning after December 15, 2021 and must be applied using either a modified or full retrospective approach. Early adoption is permitted for interim or annual reporting periods beginning after December 15, 2020. The Company is currently evaluating the impact of the adoption of this ASU on its financial statements.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	3. PROPERTY AND EQUIPMENT Property and equipment consisted of the following at September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 Computer hardware and software $ 62,978 $ 60,749 Leasehold improvements 60,535 60,535 Furniture and fixtures 145,487 145,487 Subtotal property and equipment, gross 269,000 266,771 Less accumulated depreciation (125,855 ) (72,797 ) Property and equipment, net $ 143,145 $ 193,974

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2020
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued Expenses	4. ACCRUED EXPENSES Accrued expenses consisted of the following at September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 Accrued contract manufacturing $ 1,037,934 $ 655,207 Accrued contract research and regulatory consulting 804,055 418,000 Accrued legal 415,959 152,340 Accrued payroll and payroll taxes 271,170 153,238 Accrued license fees 229,128 — Accrued accounting, audit, and tax fees 107,306 147,850 Accrued miscellaneous expenses 72,938 56,598 Accrued consulting 15,158 109,073 Accrued precommercial costs — 252,125 Total accrued expenses $ 2,953,648 $ 1,944,431

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	5. LEASES On March 6, 2018, the Company entered into a lease agreement (the “Newton Lease”), commencing on October 1, 2018, for certain premises which consist of 2,760 square feet of office space located in Newton, Massachusetts (the “Newton Premises”) to serve as its corporate headquarters. On March 5, 2019, the Company entered into a lease agreement to amend the Newton Lease and to lease an additional 1,600 square feet of office space, commencing on June 1, 2019, located in Newton, Massachusetts (the “Additional Newton Premises”) to serve as additional space for its corporate headquarters. The term of the leases for the Newton Premises and the Additional Newton Premises expires on May 31, 2022. In addition, the Company is required to share in certain taxes and operating expenses of the Newton Premises and the Additional Newton Premises. The Company entered into a Triple Net Lease (the “Bend Lease”) effective April 1, 2018 for certain premises consisting of 2,288 square feet of office space located in Bend, Oregon (the “Bend Premises”) to serve as a satellite facility. On April 23, 2019, the Company entered into a lease agreement to amend the Bend Lease and to lease additional office space, commencing on May 1, 2019, located in Bend, Oregon (the “Additional Bend Premises”). The term of the lease for the Bend Premises and the Additional Bend Premises expires on March 31, 2022 (the “Bend Term”). The Company has an option to extend the Bend Term for up to two additional periods of three years and a right of first refusal to lease an additional suite in the same building. The leases for the Newton Premises, the Additional Newton Premises, the Bend Premises, and the Additional Bend Premises are classified as operating leases. In the first quarter of 2019, the Company adopted ASU 2016-02 and recorded a non-cash transaction to recognize a right-of-use asset of $0.4 million in other non-current assets, as well as a lease liability of $0.2 million in other current liabilities and $0.2 million in other non-current liabilities. Since the adoption of ASU 2016-02, the Company has recognized additional right-of-use assets totaling $0.3 million as well as additional lease liabilities totaling $0.1 million in other current liabilities and $0.2 million in other non-current liabilities in conjunction with the commencement of the leases for the Additional Newton Premises and the Additional Bend Premises. The Company’s lease liability represents the net present value of future lease payments utilizing a discount rate of 8%, which corresponds to the Company’s incremental borrowing rate. As of September 30, 2020, the weighted average remaining lease term was 1.7 years. For the three and nine months ended September 30, 2020, the Company recorded expense of $0.1 million and $0.2 million, respectively, related to the leases. For each of the three and nine months ended September 30, 2019, the Company recorded expense of $0.1 million related to the leases. During the three and nine months ended September 30, 2020, the Company made cash payments of $0.1 million and $0.2 million, respectively, for amounts included in the measurement of lease liabilities. During each of the three and nine months ended September 30, 2019, the Company made cash payments of $0.1 million. The Company is therefore reporting a right-of-use asset of $0.4 million in Other non-current assets and lease liabilities totaling $0.4 million in Other current liabilities and Other non-current liabilities as of September 30, 2020. The following table reconciles the undiscounted lease liabilities to the total lease liabilities recognized on the unaudited condensed balance sheet as of September 30, 2020: Undiscounted lease liabilities for years ending December 31,: 2020 (remaining) $ 66,528 2021 273,158 2022 115,951 Total undiscounted lease liabilities $ 455,637 Less effects of discounting (32,593 ) Total lease liabilities as of September 30, 2020 $ 423,044 Reported as of September 30, 2020: Other current liabilities $ 270,115 Other non-current liabilities 152,929 Total lease liabilities $ 423,044 Future minimum lease payments at December 31, 2019 were as follows: Years Ending December 31: Minimum Lease Payments 2020 $ 263,392 2021 273,158 2022 115,951 Total $ 652,501

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6 . COMMITMENTS AND CONTINGENCIES License Agreements In April 2014, Private Acer obtained exclusive rights to intellectual property relating to ACER-001 and preclinical and clinical data, through a license agreement with Baylor College of Medicine (“BCM”). Under the terms of the agreement, as amended, the Company has worldwide exclusive rights to develop, manufacture, use, sell and import licensed products as defined in the agreement. The license agreement requires the Company to make certain upfront and annual payments to BCM, as well as reimburse certain legal costs, make payments upon achievement of defined milestones, and pay royalties in the low single-digit percent range on net sales of any developed product over the royalty term. In August 2016, Private Acer signed an agreement with Assistance Publique—Hôpitaux de Paris, Hôpital Européen Georges Pompidou (“AP-HP”) (via its Department of Clinical Research and Development) granting the Company the exclusive worldwide rights to access and use data from a randomized, controlled clinical study of celiprolol. The Company used this pivotal clinical data to support an NDA regulatory filing for EDSIVO TM In September 2018, the Company entered into a License Agreement for Development and Exploitation with AP-HP to acquire the exclusive worldwide intellectual property rights to three European patent applications relating to certain uses of celiprolol including (i) the optimal dose of celiprolol in treating vEDS patients, (ii) the use of celiprolol during pregnancy and (iii) the use of celiprolol to treat kyphoscoliotic Ehlers-Danlos syndrome (type VI). Pursuant to the agreement, the Company will reimburse AP-HP for certain costs and will pay annual maintenance fee payments. Subject to a minimum royalty amount, the Company will also pay royalty payments on annual net sales of celiprolol during the royalty term in the low single digit percent range, depending upon whether there is a valid claim of a licensed patent. Under the agreement, the Company will control and pay the costs of ongoing patent prosecution and maintenance for the licensed applications. The Company may terminate the agreement in its sole discretion upon written notice to AP-HP, and AP-HP may terminate the agreement in the event the Company fails to make the required payments after notice and opportunity to cure. Additionally, the agreement will terminate if the Company terminates clinical development, marketing approval is withdrawn by the health or regulatory authorities in all countries, the Company ceases to do business or there is a procedure of winding-up by court decision against the Company. The Company subsequently filed three U.S. patent applications on this subject matter in October 2018. In December 2018, the Company entered into an exclusive license agreement with Sanofi granting the Company worldwide rights to osanetant, a clinical-stage, selective, non-peptide tachykinin NK3 receptor antagonist. The agreement required the Company to make a certain upfront payment to Sanofi, make payments upon achievement of defined development and sales milestones and pay royalties on net sales of osanetant over the royalty term. The Company plans to initially pursue development of osanetant as a potential treatment for iVMS. Paycheck Protection Program (“PPP”) Loan On April 11, 2020, the Company was advised that its principal bank, JPMorgan Chase Bank, N.A., had approved a $0.6 million loan under the PPP pursuant to the CARES Act that was signed into law on March 27, 2020. As a U.S. small business, the Company has qualified for the PPP, which allows businesses and nonprofits with fewer than 500 employees to obtain loans of up to $10 million to incent companies to maintain their workers as they manage the business disruptions caused by the COVID-19 pandemic. The loan, evidenced by a promissory note to JPMorgan Chase Bank, N.A. as lender, has a term of two years, is unsecured, and is guaranteed by the Small Business Administration. The loan bears interest at a fixed rate of one percent per annum, with the first six months of interest and principal deferred. Some or all of the loan may be forgiven if at least 75% of the loan proceeds are used by the Company to cover payroll costs, including benefits, and if the Company maintains its employment and compensation within certain parameters during the period following the loan origination date and complies with other relevant conditions. On June 5, 2020, the Payroll Protection Flexibility Act of 2020 was signed into law, adjusting certain terms of the loans issued under the PPP, including extending the initial deferral period from six to up to ten months, reducing from 75% to 60% the portion of loan proceeds required to be used to cover payroll costs, and allowing borrowers to elect a 24-week rather than an eight-week period related to employment and compensation provisions. There can be no assurance that this PPP loan can be forgiven. The Company recorded the liability associated with the loan in Other current liabilities and Other non-current liabilities and accounts for the loan according to ASC 470. Litigation From time to time, the Company may become involved in litigation or proceedings relating to claims arising out of its operations. Piper vs. Acer Therapeutics Inc. On September 27, 2017, Piper Sandler & Co. (“Piper”) filed a lawsuit against the Company, Piper Sandler & Co. v. Acer Therapeutics Inc., Index No. 656055/2017, in the Supreme Court of the State of New York, County of New York. The complaint alleges that the Company breached its obligations to Piper pursuant to an August 30, 2016 engagement letter between the parties and an April 28, 2017 addendum thereto by failing to pay Piper (i) a fee of $1.1 million in connection with the financing which closed on September 19, 2017 for aggregate consideration of $15.7 million and (ii) $0.1 million in reimbursement for expenses incurred by Piper pursuant to the engagement letter. On November 10, 2017, the Company filed an answer and counterclaim in the lawsuit, denying Piper’s breach of contract allegation, asserting several defenses, and bringing several counterclaims, including claims for breach of contract and breach of the duty of good faith and fair dealing. Piper filed a reply to the counterclaims denying the essential allegations, and fact discovery has largely concluded. On February 22, 2019, Piper filed a motion for summary judgment. On March 26, 2020, the Court denied Piper’s motion in part, as to Piper’s claim and the Company’s counterclaim for damages, and granted in part, as to certain counterclaims by the Company. Discovery is ongoing in the case. Pursuant to the Court’s directive, the parties have submitted a joint request for a pre-trial conference, which has not yet been scheduled. The Company has not recorded a liability as of September 30, 2020 because a potential loss is not probable or reasonably estimable given the status of the proceedings. The Securities Class Action On July 1, 2019, plaintiff Tyler Sell filed a putative class action lawsuit, Sell v. Acer Therapeutics Inc. et al TM Skiadas v. Acer Therapeutics Inc. et al The Stockholders’ Derivative Actions On August 12, 2019, a stockholder’s derivative action, Gress v. Aselage et al Skiadas Giroux v. Amello et al. Skiadas Gress Gress Giroux King v. Schelling et al Skiadas Gress Giroux Diaz v. Amello et al. Gress Diaz In re Acer Therapeutics Inc. Derivative Litigation

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders' Equity	7. STOCKHOLDERS’ EQUITY At-the-Market Facility On November 9, 2018, the Company entered into a sales agreement with Roth Capital Partners, LLC, and on March 18, 2020, the Company entered into an amended and restated sales agreement with JonesTrading Institutional Services LLC and Roth Capital Partners, LLC. The agreement provides a facility for the offer and sale of shares of common stock from time to time having an aggregate offering price of up to $50 million depending upon market demand, in transactions deemed to be an “at-the-market” (“ATM”) offering. Any such sales would be effected pursuant to the Company’s registration statement on Form S-3 (File No. 333-228319), declared effective by the SEC on November 21, 2018. The Company has no obligation to sell any shares of common stock pursuant to the agreement and may at any time suspend sales pursuant to the agreement. Each party may terminate the agreement at any time without liability . Private Placement On July 24, 2020, the Company entered into a securities purchase agreement for the sale and issuance of an aggregate of 244,998 shares of the Company’s common stock, for an aggregate purchase price of $0.9 million, in a Private Placement with certain directors, officers, and employees at a price per share of $3.50. The shares of common stock issued in the Private Placement constitute “restricted securities” under the federal securities laws and are subject to a minimum six-month holding period. Common Stock Purchase Agreement On April 30, 2020, the Company entered into a purchase agreement and a registration rights agreement pursuant to which Lincoln Park has committed to purchase up to $15.0 million of the Company’s common stock. Under the terms and subject to the conditions of the purchase agreement, the Company has the right, but not the obligation, to sell to Lincoln Park, and Lincoln Park is obligated to purchase up to $15.0 million of the Company’s common stock. Such sales of common stock by the Company will be subject to certain limitations, and may occur from time to time, at the Company’s sole discretion, over the 36-month period commencing on June 8, 2020. The number of shares the Company may sell to Lincoln Park on any single business day in a regular purchase is 50,000, but that amount may be increased up to 100,000 shares, depending upon the market price of the Company’s common stock at the time of sale and subject to a maximum limit of $1.0 million per regular purchase. The purchase price per share for each such regular purchase will be based on prevailing market prices of the Company’s common stock immediately preceding the time of sale as computed under the purchase agreement. In addition to regular purchases, the Company may also direct Lincoln Park to purchase other amounts as accelerated purchases or as additional accelerated purchases if the closing sale price of the common stock exceeds certain threshold prices as set forth in the purchase agreement. As of September 30, 2020, the Company has not sold any shares of common stock under the purchase agreement. See Note 10, “Subsequent Events”, regarding subsequent events related to the purchase agreement. Under applicable rules of the Nasdaq Capital Market, in no event may the Company issue or sell to Lincoln Park under the purchase agreement more than 19.99% of the shares of the Company’s common stock outstanding immediately prior to the execution of the purchase agreement, unless (i) the Company obtains stockholder approval to issue shares of common stock in excess of the Exchange Cap or (ii) the average price of all applicable sales of common stock to Lincoln Park under the purchase agreement equals or exceeds $2.1668, such that issuances and sales of the common stock to Lincoln Park under the purchase agreement would be exempt from the issuance limitation under applicable Nasdaq rules. The Company determined that the right to sell additional shares represents a freestanding put option under ASC 815 Derivatives and Hedging, but has a fair value of zero, and therefore no additional accounting was required. Lincoln Park has no right to require the Company to sell any shares of common stock to Lincoln Park, but Lincoln Park is obligated to make purchases as the Company directs, subject to certain conditions. In all instances, the Company may not sell shares of its common stock to Lincoln Park under the purchase agreement if doing so would result in Lincoln Park beneficially owning more than 9.99% of its common stock. Actual sales of shares of common stock to Lincoln Park under the purchase agreement will depend on a variety of factors to be determined by the Company from time to time, including, among others, market conditions, the trading price of the common stock and determinations by the Company as to the appropriate sources of funding for the Company and its operations. The proceeds under the purchase agreement to the Company will depend on the frequency and prices at which the Company sells shares of its stock to Lincoln Park. The Company issued 148,148 shares of common stock to Lincoln Park as a commitment fee in connection with entering into the purchase agreement. The $0.4 million fair value of the commitment fee shares was recorded to General and administrative expense along with other costs incurred in connection with entering into the purchase agreement. 2018 Stock Incentive Plan The Company’s 2018 Stock Incentive Plan (the “2018 Plan”), adopted on May 14, 2018, provides for the grant of up to 500,000 shares of common stock as stock options, restricted stock, stock appreciation rights, restricted stock units, performance-based awards and cash-based awards that may be settled in cash, stock or other property to employees, executive officers, directors, and consultants. In addition to the 500,000 shares, the total number of shares reserved for issuance under the 2018 Plan also consists of the sum of the number of shares subject to outstanding awards under the Company’s 2010 Stock Incentive Plan, as amended and restated (the “2010 Plan”), and the 2013 Stock Incentive Plan, as amended (the “2013 Plan”), as of the effective date of the 2018 Plan that are subsequently forfeited or terminated for any reason prior to being exercised or settled, plus the number of shares subject to vesting restrictions under the 2010 Plan and the 2013 Plan on the effective date of the 2018 Plan that are subsequently forfeited, plus the number of shares reserved but not issued or subject to outstanding grants under the 2010 Plan and the 2013 Plan as of the effective date of the 2018 Plan, up to a maximum of 635,170 shares in aggregate. In addition, the number of shares authorized for issuance under the 2018 Plan is automatically increased (the “evergreen provision”) on the first day of each fiscal year beginning on January 1, 2019, and ending on (and including) January 1, 2028, in an amount equal to the lesser of (i) 4% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year, or (ii) another amount (including zero) determined by the Company’s Board of Directors. Any shares subject to awards granted under the 2018 Plan that are forfeited or terminated before being exercised or settled, or are not delivered to the participant because such award is settled in cash, will again become available for issuance under the 2018 Plan. Shares withheld to satisfy the grant, exercise price or tax withholding obligation related to an award will again become available for issuance under the 2018 Plan. The 2018 Plan is administered by the Company’s Board of Directors, which may in turn delegate authority to administer the plan to a committee such as the Compensation Committee, referred to herein as the 2018 Plan administrator. Subject to the terms of the 2018 Plan, the 2018 Plan administrator will determine recipients, the number of shares or amount of cash subject to awards to be granted, whether an option is to be an incentive stock options or non-incentive stock options and the terms and conditions of the stock awards, including the period of their exercisability and vesting. Subject to the limitations set forth below, the 2018 Plan administrator will also determine the exercise price of options granted under the 2018 Plan. The 2018 Plan expressly provides that, without the approval of the stockholders, the 2018 Plan administrator does not have the authority to reduce the exercise price of any outstanding stock options or stock appreciation rights under the 2018 Plan (except in connection with certain corporate transactions, such as stock splits, certain dividends, recapitalizations, reorganizations, mergers, spin-offs and the like), or cancel any outstanding underwater stock options or stock appreciation rights in exchange for cash or new stock awards under the 2018 Plan. Option awards are generally granted with an exercise price equal to the fair value of the common stock at the date of grant and have contractual terms of 10 years. Stock options granted to executive officers and employees generally vest either 1) over a four-year period, with 25% vesting on the one-year anniversary of the grant date and the remaining 75% vesting quarterly over the remaining three years, assuming continued service, and with vesting acceleration in full immediately prior to a change in control, or 2) for certain stock options granted on September 18, 2019, 50% vest on each of January 1, 2021 and January 1, 2022, assuming continued service, and with vesting acceleration in full immediately prior to a change in control. Restricted stock units generally vest and are settled upon the first anniversary of the grant date. At September 30, 2020, after the authorization on January 1, 2020 of 403,807 additional shares according to the evergreen provision, 525,265 shares of common stock remained available for the grant of future awards under the 2018 Plan. 2013 Stock Incentive Plan The Company’s 2013 Plan provided for the issuance of up to 165,000 shares of common stock as incentive or non-qualified stock options and/or restricted common stock to employees, officers, directors, consultants and advisers. Option awards were generally granted with an exercise price equal to the fair value of the common stock at the date of grant and had contractual terms of 10 years. At September 30, 2020, all shares available under the 2013 Plan were subject to outstanding equity awards, and no new awards may be granted under the 2013 Plan. 2010 Stock Incentive Plan The Company’s 2010 Plan, as amended and restated, provided for the grant of up to 470,170 shares of common stock as incentive or non-qualified stock options, stock appreciation rights, restricted stock units and/or restricted common stock to employees, officers, directors, consultants and advisers. Option awards were generally granted with an exercise price equal to the fair value of the common stock at the date of grant and had contractual terms of 10 years. At September 30, 2020, all shares available under the 2010 Plan were subject to outstanding equity awards, and no new awards may be granted under the 2010 Plan. A summary of option activity under the 2018 Plan, 2013 Plan, and 2010 Plan for the nine months ended September 30, 2020, is as follows: Year-to-Date Activity Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in millions) Options outstanding at December 31, 2019 1,313,475 $ 12.28 8.7 Granted 133,500 3.61 Cancelled/forfeited (89,812 ) 11.92 Options outstanding at September 30, 2020 1,357,163 11.46 7.7 — Options exercisable at September 30, 2020 535,848 $ 15.21 6.1 — A summary of restricted stock unit activity under the 2018 Plan for the nine months ended September 30, 2020, is as follows: Year-to-Date Activity Number of Shares Weighted Average Grant Date Fair Value Per Share Aggregate Intrinsic Value (in millions) Non-vested outstanding at December 31, 2019 9,000 $ 23.60 Granted — — Vested/settled (5,858 ) Cancelled/forfeited (3,142 ) Non-vested outstanding at September 30, 2020 — — — At September 30, 2020, there was $3.5 million of unrecognized compensation expense related to the stock-based compensation arrangements granted under all plans. The average remaining vesting period for options was 1.6 years. The weighted average grant date fair value of options granted during the nine months ended September 30, 2020 was $2.03. The amount of stock-based compensation expense recorded to research and development expenses and to general and administrative expenses is detailed in table below: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Stock-based compensation Research and development $ 115,817 $ 166,289 $ 606,470 $ 785,423 General and administrative 371,586 397,735 1,151,845 1,165,894 $ 487,403 $ 564,024 $ 1,758,315 $ 1,951,317

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	8 . NET LOSS PER SHARE Basic net loss per share is computed by dividing the net loss in each period by the weighted-average number of common shares outstanding during such period. Diluted net loss per share is computed similarly to basic net loss per share except that the denominator is increased to include the number of additional common shares that would have been outstanding if the potential common shares had been issued and if the additional common shares were dilutive. For the periods presented, common stock equivalents, consisting of stock-based awards, were not included in the calculation of the diluted loss per share because to do so would be anti-dilutive. As of September 30, 2020 and 2019, the number of shares of common stock underlying potentially dilutive securities are comprised of: September 30, 2020 2019 Options to purchase common stock and unvested, unsettled restricted stock units 1,357,163 1,394,664 Total 1,357,163 1,394,664

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2020
Restructuring And Related Activities [Abstract]
Restructuring	9. RESTRUCTURING In June 2019, the Company received a Complete Response Letter from the FDA regarding its NDA for EDSIVO TM TM

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	10. SUBSEQUENT EVENTS Subsequent to September 30, 2020, during multiple trading days through October 8, 2020, the Company sold an aggregate of 72,274 shares of common stock under its ATM facility at an average gross sale price of $3.1456 per share, resulting in proceeds of $0.2 million. Subsequent to September 30, 2020, through October 26, 2020, the Company sold 300,000 shares of common stock under its purchase agreement with Lincoln Park at a weighted average price of $2.77 per share, resulting in proceeds of $0.8 million.

Significant Accounting Polices

Significant Accounting Polices (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Liquidity	Liquidity The Company had an accumulated deficit of $92.9 million and cash and cash equivalents of $6.2 million as of September 30, 2020. Net cash used in operating activities was $13.1 million and $25.5 million for the nine months ended September 30, 2020 and 2019, respectively. On November 9, 2018, the Company entered into a sales agreement with Roth Capital Partners, LLC, and on March 18, 2020, an amended and restated sales agreement was entered into with JonesTrading Institutional Services LLC and Roth Capital Partners, LLC. The agreement provides a facility for the offer and sale of shares of common stock from time to time having an aggregate offering price of up to $50 million depending upon market demand, in transactions deemed to be an at-the-market (“ATM”) offering. Any such sales would be effected pursuant to the Company’s registration statement on Form S-3 (File No. 333-228319), declared effective by the SEC on November 21, 2018 . On April 30, 2020, the Company entered into a purchase agreement and registration rights agreement pursuant to which Lincoln Park Capital Fund, LLC (“Lincoln Park”) has committed to purchase up to $15.0 million of the Company’s common stock. Under the terms and subject to the conditions of the purchase agreement, the Company has the right, but not the obligation, to sell to Lincoln Park, and Lincoln Park is obligated to purchase up to $15.0 million of the Company’s common stock. Such sales of common stock by the Company will be subject to certain limitations, and may occur from time to time, at the Company’s sole discretion, over the 36-month period commencing on June 8, 2020. The number of shares the Company may sell to Lincoln Park on any single business day in a regular purchase is 50,000, but that amount may be increased up to 100,000 shares, depending upon the market price of the Company’s common stock at the time of sale and subject to a maximum limit of $1.0 million per regular purchase. The purchase price per share for each such regular purchase will be based on prevailing market prices of the Company’s common stock immediately preceding the time of sale as computed under the purchase agreement. In addition to regular purchases, the Company may also direct Lincoln Park to purchase other amounts as accelerated purchases or as additional accelerated purchases if the closing sale price of the common stock exceeds certain threshold prices as set forth in the purchase agreement. The Company issued 148,148 shares of common stock to Lincoln Park as a commitment fee in connection with entering into the purchase agreement. The $0.4 million fair value of the commitment fee shares was recorded to General and administrative expense along with other costs incurred in connection with entering into the purchase agreement. On July 24, 2020, the Company entered into a securities purchase agreement for the sale and issuance of an aggregate of 244,998 shares of the Company’s common stock, for an aggregate purchase price of $0.9 million, in a private placement transaction (“Private Placement”) with certain directors, officers, and employees at a price per share of $3.50. The shares of common stock issued in the Private Placement constitute “restricted securities” under the federal securities laws and are subject to a minimum six-month holding period. The Company’s existing cash and cash equivalents available at September 30, 2020, combined with the funds raised subsequent to September 30, 2020 via the ATM and equity line, are expected to fund operations into the first quarter of 2021 and enable it to advance emetine toward Investigational New Drug Application (“IND”) submission, continue to advance ACER-001 toward New Drug Application (“NDA”) submission, submit a plan with respect to EDSIVO TM Management expects to continue to finance operations through the issuance of additional equity or debt securities, non-dilutive funding, and/or through strategic collaborations. Any transactions which occur may contain covenants that restrict the ability of management to operate the business and any securities issued may have rights, preferences, or privileges senior to the Company’s common stock and may dilute the ownership of current stockholders of the Company.
Going Concern	Going Concern The accompanying financial statements have been prepared in conformity with GAAP, which contemplate continuation of the Company as a going concern. The Company has not established a source of revenues and, as such, has been dependent on funding operations through the sale of equity securities. Since inception, the Company has experienced significant losses and incurred negative cash flows from operations. The Company has an accumulated deficit of $92.9 million as of September 30, 2020 and expects to incur further losses over the next several years as it develops its business. The Company has spent, and expects to continue to spend, a substantial amount of funds in connection with implementing its business strategy, including its planned product development efforts and potential precommercial activities. As of September 30, 2020, the Company had cash and cash equivalents of $6.2 million and current liabilities of $4.5 million. The Company’s cash and cash equivalents available at September 30, 2020, combined with the funds raised subsequent to September 30, 2020 via the ATM and equity line, are expected to fund operations into the first quarter of 2021, excluding support for a planned emetine Phase 2/3 clinical trial, which is also subject to ongoing discussions with the FDA. The Company will need to raise additional capital to fund continued operations in 2021. The Company may not be successful in its efforts to raise additional funds or achieve profitable operations. The Company continues to explore potential opportunities and alternatives to obtain the additional resources that will be necessary to support its ongoing operations through and beyond the next 12 months, including raising additional capital through either private or public equity or debt financing or non-dilutive funding, as well as using its ATM facility and/or its $15.0 million equity line facility entered into on April 30, 2020 with Lincoln Park, which is subject to certain limitations and conditions. The Company has no commitments for any additional financing, except for the agreement with Lincoln Park. Any amounts raised will be used for further development of its product candidates, precommercial activities, potential acquisitions of additional product candidates, and for other working capital purposes. If the Company is unable to obtain additional funding to support its current or proposed activities and operations, it may not be able to continue its operations as proposed, which may require it to suspend or terminate any ongoing development activities, modify its business plan, curtail various aspects of its operations, cease operations, or seek relief under applicable bankruptcy laws. In such event, the Company’s stockholders may lose a substantial portion or even all of their investment. These factors individually and collectively raise substantial doubt about the Company’s ability to continue as a going concern for twelve months from the date these financial statements are available, or November 10, 2020. The accompanying unaudited condensed financial statements do not include any adjustments or classifications that may result from the possible inability of the Company to continue as a going concern.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less at the date of purchase to be cash equivalents. The Company follows the provisions of ASC Topic 820, Fair Value Measurement, which establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The Company considers its investments in money market funds of $5.7 million and $11.6 million as of September 30, 2020 and December 31, 2019, respectively, included in cash and cash equivalents, to be Level 1, which are based on unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. The estimated fair value of the Company’s financial instruments, which include cash and cash equivalents, accounts payable, and accrued liabilities approximates their carrying value, based upon their short-term maturities or prevailing interest rates.
Goodwill	Goodwill Goodwill represents the excess of the purchase price (consideration paid plus net liabilities assumed) of an acquired business over the fair value of the underlying net tangible and intangible assets. The Company evaluates the recoverability of goodwill according to ASU No. 2017-04, Intangibles – Goodwill and Other a respiratory illness caused by a novel coronavirus
Stock-Based Compensation	Stock-Based Compensation The Company records stock-based payments at fair value. The measurement date for compensation expense related to awards is generally the date of the grant. The fair value of awards is recognized as an expense in the condensed statement of operations over the requisite service period, which is generally the vesting period. The fair value of options is calculated using the Black-Scholes option pricing model. This option valuation model requires the use of assumptions including, among others, the volatility of stock price, the expected term of the option, and the risk-free interest rate. The following assumptions were used to estimate the fair value of stock options granted during the nine months ended September 30, 2020 and 2019 using the Black-Scholes option pricing model: 2020 2019 Risk-free interest rate 0.36% – 1.61% 1.68% – 2.57% Expected life (years) 6.25 6.25 Volatility 60% 60% Dividend rate 0% 0%
Use of Estimates	Use of Estimates The Company’s accounting principles require management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of assets and liabilities at the date of the condensed financial statements and reported amounts of revenues and expenses during the reporting period. Estimates having relatively higher significance include stock-based compensation, contract manufacturing accruals, and income taxes. Actual results could differ from those estimates and changes in estimates may occur.
Income Taxes	Income Taxes The Company recorded no income tax expense or benefit during the three and nine months ended September 30, 2020 and 2019, due to a full valuation allowance recognized against its net deferred tax assets. The Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was enacted in the U.S. on March 27, 2020 . The CARES Act, among other things, includes provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations, increased limitations on qualified charitable contributions, and technical corrections to tax depreciation methods for qualified improvement property. The Company is required to recognize the effects of tax law changes in the period of enactment. The enactment of the CARES Act did not result in material adjustments for the income tax provision for the three and nine months ended or to the Company’s assessment of the realizability of deferred tax assets as the carry back of net operating losses was used as a source of income. There were no other effects to the Company’s tax provision as a result of the CARES Act as of September 30, 2020.
Basic and Diluted Net Loss per Common Share	Basic and Diluted Net Loss per Common Share Basic and diluted net loss per common share is computed by dividing net loss in each period by the weighted average number of shares of common stock outstanding during such period. For the periods presented, common stock equivalents, consisting of stock-based awards, were not included in the calculation of the diluted loss per share because to do so would be anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other Options The amendments of this ASU are effective for fiscal years beginning after December 15, 2021 and must be applied using either a modified or full retrospective approach. Early adoption is permitted for interim or annual reporting periods beginning after December 15, 2020. The Company is currently evaluating the impact of the adoption of this ASU on its financial statements.

Significant Accounting Police_2

Significant Accounting Polices (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of Estimate Fair Value of Stock Options Granted	The following assumptions were used to estimate the fair value of stock options granted during the nine months ended September 30, 2020 and 2019 using the Black-Scholes option pricing model: 2020 2019 Risk-free interest rate 0.36% – 1.61% 1.68% – 2.57% Expected life (years) 6.25 6.25 Volatility 60% 60% Dividend rate 0% 0%

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consisted of the following at September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 Computer hardware and software $ 62,978 $ 60,749 Leasehold improvements 60,535 60,535 Furniture and fixtures 145,487 145,487 Subtotal property and equipment, gross 269,000 266,771 Less accumulated depreciation (125,855 ) (72,797 ) Property and equipment, net $ 143,145 $ 193,974

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2020
Accounts Payable And Accrued Liabilities Current [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following at September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 Accrued contract manufacturing $ 1,037,934 $ 655,207 Accrued contract research and regulatory consulting 804,055 418,000 Accrued legal 415,959 152,340 Accrued payroll and payroll taxes 271,170 153,238 Accrued license fees 229,128 — Accrued accounting, audit, and tax fees 107,306 147,850 Accrued miscellaneous expenses 72,938 56,598 Accrued consulting 15,158 109,073 Accrued precommercial costs — 252,125 Total accrued expenses $ 2,953,648 $ 1,944,431

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Reconciliation of Undiscounted Lease Liabilities to Total Lease Liabilities	The following table reconciles the undiscounted lease liabilities to the total lease liabilities recognized on the unaudited condensed balance sheet as of September 30, 2020: Undiscounted lease liabilities for years ending December 31,: 2020 (remaining) $ 66,528 2021 273,158 2022 115,951 Total undiscounted lease liabilities $ 455,637 Less effects of discounting (32,593 ) Total lease liabilities as of September 30, 2020 $ 423,044 Reported as of September 30, 2020: Other current liabilities $ 270,115 Other non-current liabilities 152,929 Total lease liabilities $ 423,044
Future Minimum Lease Payments	Future minimum lease payments at December 31, 2019 were as follows: Years Ending December 31: Minimum Lease Payments 2020 $ 263,392 2021 273,158 2022 115,951 Total $ 652,501

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Summary of Option Activity under 2018 Plan, 2013 Plan and 2010 Plan	A summary of option activity under the 2018 Plan, 2013 Plan, and 2010 Plan for the nine months ended September 30, 2020, is as follows: Year-to-Date Activity Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in millions) Options outstanding at December 31, 2019 1,313,475 $ 12.28 8.7 Granted 133,500 3.61 Cancelled/forfeited (89,812 ) 11.92 Options outstanding at September 30, 2020 1,357,163 11.46 7.7 — Options exercisable at September 30, 2020 535,848 $ 15.21 6.1 —
Summary of Restricted Stock Unit Activity under 2018 Plan	A summary of restricted stock unit activity under the 2018 Plan for the nine months ended September 30, 2020, is as follows: Year-to-Date Activity Number of Shares Weighted Average Grant Date Fair Value Per Share Aggregate Intrinsic Value (in millions) Non-vested outstanding at December 31, 2019 9,000 $ 23.60 Granted — — Vested/settled (5,858 ) Cancelled/forfeited (3,142 ) Non-vested outstanding at September 30, 2020 — — —
Summary of Stock-Based Compensation Expense	The amount of stock-based compensation expense recorded to research and development expenses and to general and administrative expenses is detailed in table below: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Stock-based compensation Research and development $ 115,817 $ 166,289 $ 606,470 $ 785,423 General and administrative 371,586 397,735 1,151,845 1,165,894 $ 487,403 $ 564,024 $ 1,758,315 $ 1,951,317

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Number of Shares of Common Stock Underlying Potentially Dilutive Securities	As of September 30, 2020 and 2019, the number of shares of common stock underlying potentially dilutive securities are comprised of: September 30, 2020 2019 Options to purchase common stock and unvested, unsettled restricted stock units 1,357,163 1,394,664 Total 1,357,163 1,394,664

Nature of Operations and Basi_2

Nature of Operations and Basis of Presentation - Additional Information (Details) - USD ($)	Jul. 24, 2020	Apr. 30, 2020	Mar. 18, 2020	Sep. 19, 2017	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Organization Consolidation and Presentation of Financial Statement [Line Items]
Accumulated deficit					$ 92,898,278		$ 76,250,512
Cash and cash equivalents					6,157,448		$ 12,077,640
Net cash used in operating activities					13,147,533	$ 25,515,573
Proceeds from issuance of common stock, net of issuance costs					$ 6,667,091
Common stock, shares issued					11,912,731		10,095,176
Current liabilities					$ 4,489,424		$ 2,768,913
Merger of Private Acer with opexa therapeutics incorporation and Opexa Merger Sub Incorporation
Organization Consolidation and Presentation of Financial Statement [Line Items]
Business combination date of completion				Sep. 19, 2017
Business combination date of agreement				Jun. 30, 2017
Merger and Reincorporation
Organization Consolidation and Presentation of Financial Statement [Line Items]
Merger incorporation description					On May 15, 2018, the Company changed its state of incorporation from the State of Texas to the State of Delaware pursuant to a plan of conversion, dated May 15, 2018. Immediately following the reincorporation, the holding company structure was eliminated by merging wholly-owned subsidiary Private Acer with and into the Company. The Company was the surviving corporation in connection with the subsidiary merger.
Date of reincorporation					May 15, 2018
Lincoln Park
Organization Consolidation and Presentation of Financial Statement [Line Items]
Shares value committed to be issued under agreement		$ 15,000,000
Expected increase in maximum number of common stock shares may sell in single business day on regular purchases		100,000
Maximum number of common stock shares may sell in single business day on regular purchases		50,000
Market price of common stock at the time of sale and subject to maximum limit per regular purchase		$ 1,000,000
Issuance of common stock for commitment fee, shares		148,148
Fair value of the commitment fee shares, recorded to general and administrative expense along with other costs		$ 400,000
Cost, Product and Service [Extensible List]		us-gaap:GeneralAndAdministrativeExpenseMember
Common stock, shares issued					0
Maximum | Lincoln Park
Organization Consolidation and Presentation of Financial Statement [Line Items]
Shares value committed to be issued under agreement		$ 15,000,000
At-the-Market Facility
Organization Consolidation and Presentation of Financial Statement [Line Items]
Issuance of common stock					1,418,551
Proceeds from issuance of common stock gross					$ 6,100,000
Common stock offering costs					300,000
Proceeds from issuance of common stock, net of issuance costs					$ 5,800,000
At-the-Market Facility | Weighted Average
Organization Consolidation and Presentation of Financial Statement [Line Items]
Issuance of common stock, price per share					$ 4.2664
At-the-Market Facility | Maximum
Organization Consolidation and Presentation of Financial Statement [Line Items]
Aggregate offering price of common stock			$ 50,000,000
Private Placement | Directors, Officers and Employees
Organization Consolidation and Presentation of Financial Statement [Line Items]
Issuance of common stock	244,998
Issuance of common stock, price per share	$ 3.50
Proceeds from issuance of common stock, net of issuance costs	$ 900,000

Significant Accounting Police_3

Significant Accounting Polices - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Schedule Of Significant Accounting Policies [Line Items]
Income tax expense (benefit)	$ 0	$ 0	$ 0	$ 0
Cash and Cash Equivalents
Schedule Of Significant Accounting Policies [Line Items]
Investments in money market funds	$ 5,700,000		$ 5,700,000		$ 11,600,000

Significant Accounting Police_4

Significant Accounting Polices - Schedule of Estimate Fair Value of Stock Options Granted (Details)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Accounting Policies [Abstract]
Risk-free interest rate, minimum	0.36%	1.68%
Risk-free interest rate, maximum	1.61%	2.57%
Expected life (years)	6 years 3 months	6 years 3 months
Volatility	60.00%	60.00%
Dividend rate	0.00%	0.00%

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Subtotal property and equipment, gross	$ 269,000	$ 266,771
Less accumulated depreciation	(125,855)	(72,797)
Property and equipment, net	143,145	193,974
Computer Hardware and Software
Property Plant And Equipment [Line Items]
Subtotal property and equipment, gross	62,978	60,749
Leasehold Improvements
Property Plant And Equipment [Line Items]
Subtotal property and equipment, gross	60,535	60,535
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Subtotal property and equipment, gross	$ 145,487	$ 145,487

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued contract manufacturing	$ 1,037,934	$ 655,207
Accrued contract research and regulatory consulting	804,055	418,000
Accrued legal	415,959	152,340
Accrued payroll and payroll taxes	271,170	153,238
Accrued license fees	229,128
Accrued accounting, audit, and tax fees	107,306	147,850
Accrued miscellaneous expenses	72,938	56,598
Accrued consulting	15,158	109,073
Accrued precommercial costs		252,125
Total accrued expenses	$ 2,953,648	$ 1,944,431

Leases - Additional Information

Leases - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)Term	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Mar. 05, 2019ft²	Apr. 01, 2018ft²	Mar. 06, 2018ft²
Lessee Lease Description [Line Items]
Operating lease right of use asset	$ 400,000		$ 400,000
Operating lease liability, current	270,115		270,115
Operating lease liability, non-current	$ 152,929		$ 152,929
Operating lease discount rate	8.00%		8.00%
Operating lease, weighted average remaining lease term	1 year 8 months 12 days		1 year 8 months 12 days
Operating lease, cash payment made	$ 100,000	$ 100,000	$ 200,000	$ 100,000
Operating lease expense	$ 100,000	$ 100,000	$ 200,000	$ 100,000
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent		us-gaap:OtherAssetsNoncurrent
Operating lease liability	$ 423,044		$ 423,044
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities		us-gaap:OtherLiabilities
ASU 2016-02
Lessee Lease Description [Line Items]
Operating lease right of use asset	$ 300,000		$ 300,000		$ 400,000
Operating lease liability, current	100,000		100,000		200,000
Operating lease liability, non-current	$ 200,000		$ 200,000		$ 200,000
Newton Lease | Newton, Massachusetts
Lessee Lease Description [Line Items]
Lease agreement date			Mar. 6, 2018
Lease commencement date			Oct. 1, 2018
Square feet of office space leased | ft²								2,760
Amended Newton Lease | Newton, Massachusetts
Lessee Lease Description [Line Items]
Lease agreement date			Mar. 5, 2019
Lease commencement date			Jun. 1, 2019
Square feet of office space leased | ft²						1,600
Lease expiration date			May 31, 2022
Bend Lease | Oregon
Lessee Lease Description [Line Items]
Lease agreement date			Apr. 1, 2018
Square feet of office space leased | ft²							2,288
Maximum additional periods of option to extend the bend term | Term			2
Option to extend bend term for duration period			3 years
Amended Bend Lease | Oregon
Lessee Lease Description [Line Items]
Lease agreement date			Apr. 23, 2019
Lease commencement date			May 1, 2019
Lease expiration date			Mar. 31, 2022

Leases - Reconciliation of Undi

Leases - Reconciliation of Undiscounted Lease Liabilities to Total Lease Liabilities (Details)	Sep. 30, 2020USD ($)
Undiscounted lease liabilities for years ending December 31,:
2020 (remaining)	$ 66,528
2021	273,158
2022	115,951
Total undiscounted lease liabilities	455,637
Less effects of discounting	(32,593)
Total lease liabilities as of September 30, 2020	423,044
Operating lease liability, current	270,115
Operating lease liability, non-current	152,929
Total lease liabilities	$ 423,044

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments (Details)	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 263,392
2021	273,158
2022	115,951
Total	$ 652,501

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	Jun. 05, 2020	Apr. 11, 2020USD ($)	Sep. 27, 2017USD ($)	Sep. 30, 2018Patent	Sep. 30, 2020
Commitments And Contingencies [Line Items]
Minimum percentage of loan proceeds used to cover payroll costs eligible for loan forgiven	60.00%	75.00%
Pending Litigation | Piper Sandler & Co.
Commitments And Contingencies [Line Items]
Loss contingency payable fees			$ 1.1
Loss contingency closing date			Sep. 19, 2017
Financing aggregate consideration			$ 15.7
Reimbursement expenses			$ 0.1
PPP Loan
Commitments And Contingencies [Line Items]
Debt instrument, description					On June 5, 2020, the Payroll Protection Flexibility Act of 2020 was signed into law, adjusting certain terms of the loans issued under the PPP, including extending the initial deferral period from six to up to ten months, reducing from 75% to 60% the portion of loan proceeds required to be used to cover payroll costs, and allowing borrowers to elect a 24-week rather than an eight-week period related to employment and compensation provisions.
PPP Loan | JPMorgan Chase Bank, N.A
Commitments And Contingencies [Line Items]
CARES act of 2020 aid loan amount		$ 0.6
Promissory Note | JPMorgan Chase Bank, N.A
Commitments And Contingencies [Line Items]
Debt Instrument, Term		2 years
Debt Instrument, fixed interest rate		1.00%
Assistance Publique – Hôpitaux de Paris (“AP-HP”) | License Agreement
Commitments And Contingencies [Line Items]
Agreement entered date				2018-09
Number of patent applications | Patent				3
Assistance Publique – Hôpitaux de Paris (“AP-HP”) | Private Acer | License Agreement
Commitments And Contingencies [Line Items]
Agreement entered date					2016-08

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	Jul. 24, 2020	Apr. 30, 2020	Mar. 18, 2020	Sep. 18, 2019	May 14, 2018	Sep. 19, 2017	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Stockholders Equity [Line Items]
Proceeds from issuance of common stock, net of issuance costs							$ 6,667,091
Common stock, shares issued							11,912,731		10,095,176
Number of share outstanding							1,357,163		1,313,475
Awards granted under the plan							133,500
Unrecognized compensation expense							$ 3,500,000
Share based compensation arrangement by share based payment award, Average remaining vesting period							1 year 7 months 6 days
Weighted average grant date fair value of options granted							$ 2.03
2018 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of common stock authorized for issuance					500,000			403,807
Share-based compensation arrangement by share-based payment award, description							In addition, the number of shares authorized for issuance under the 2018 Plan is automatically increased (the “evergreen provision”) on the first day of each fiscal year beginning on January 1, 2019, and ending on (and including) January 1, 2028, in an amount equal to the lesser of (i) 4% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year, or (ii) another amount (including zero) determined by the Company’s Board of Directors. Any shares subject to awards granted under the 2018 Plan that are forfeited or terminated before being exercised or settled, or are not delivered to the participant because such award is settled in cash, will again become available for issuance under the 2018 Plan. Shares withheld to satisfy the grant, exercise price or tax withholding obligation related to an award will again become available for issuance under the 2018 Plan.
Share-based compensation arrangement by share-based payment award, expiration date							Jan. 1, 2028
Share-based compensation arrangement by share-based payment award, percentage of outstanding our common stock							4.00%
Options contractual term					10 years
Available for the grant of future awards							525,265
2013 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of common stock authorized for issuance						165,000
Options contractual term						10 years
Awards granted under the plan							0
2010 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of common stock authorized for issuance						470,170
Options contractual term						10 years
Awards granted under the plan							0
Lincoln Park
Stockholders Equity [Line Items]
Shares value committed to be issued under agreement		$ 15,000,000
Common stock, shares issued							0
Maximum number of common stock shares may sell in single business day on regular purchases		50,000
Expected increase in maximum number of common stock shares may sell in single business day on regular purchases		100,000
Market price of common stock at the time of sale and subject to maximum limit per regular purchase		$ 1,000,000
Maximum percentage of shares may be issued or sold based on outstanding shares immediately prior to execution of agreement.		19.99%
Issuance of common stock for commitment fee, shares		148,148
Fair value of the commitment fee shares, recorded to general and administrative expense along with other costs		$ 400,000
Cost, Product and Service [Extensible List]		us-gaap:GeneralAndAdministrativeExpenseMember
Executive Officers and Employees | 2018 Stock Incentive Plan
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, stock options vesting period					4 years
Executive Officers and Employees | 2018 Stock Incentive Plan | One-year Anniversary of the Grant Date
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, Vesting percentage Share-based compensation arrangement by share-based payment award, Vesting percentage					25.00%
Executive Officers and Employees | 2018 Stock Incentive Plan | Quarterly over Remaining Three Years
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, Vesting percentage Share-based compensation arrangement by share-based payment award, Vesting percentage					75.00%
Executive Officers and Employees | 2018 Stock Incentive Plan | January 1, 2021
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, Vesting percentage Share-based compensation arrangement by share-based payment award, Vesting percentage				50.00%
Executive Officers and Employees | 2018 Stock Incentive Plan | January 1, 2022
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, Vesting percentage Share-based compensation arrangement by share-based payment award, Vesting percentage				50.00%
Maximum | 2010 and 2013 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of share outstanding					635,170
Maximum | Lincoln Park
Stockholders Equity [Line Items]
Shares value committed to be issued under agreement		$ 15,000,000
Beneficially ownership percentage		9.99%
Minimum | Lincoln Park
Stockholders Equity [Line Items]
Threshold price per share for issuance of shares under agreement		$ 2.1668
At-the-Market Facility
Stockholders Equity [Line Items]
Issuance of common stock							1,418,551
Gross proceeds from issuance of common stock							$ 6,100,000
Common stock offering costs							300,000
Proceeds from issuance of common stock, net of issuance costs							$ 5,800,000
At-the-Market Facility | Weighted Average
Stockholders Equity [Line Items]
Issuance of common stock, price per share							$ 4.2664
At-the-Market Facility | Maximum
Stockholders Equity [Line Items]
Aggregate offering price of common stock			$ 50,000,000
Private Placement | Directors, Officers and Employees
Stockholders Equity [Line Items]
Issuance of common stock	244,998
Issuance of common stock, price per share	$ 3.50
Proceeds from issuance of common stock, net of issuance costs	$ 900,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Option Activity under 2018 Plan, 2013 Plan and 2010 Plan (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Options
Number of Shares, Options outstanding at beginning of period	1,313,475
Number of Shares, Options Granted	133,500
Number of Shares, Cancelled/forfeited	(89,812)
Number of Shares, Options outstanding at end of period	1,357,163	1,313,475
Number of Shares, Options exercisable at end of period	535,848
Weighted Average Exercise Price, Options
Weighted Average Exercise Price, Options outstanding at beginning of period	$ 12.28
Weighted Average Exercise Price, Options Granted	3.61
Weighted Average Exercise Price, Cancelled/forfeited	11.92
Weighted Average Exercise Price, Options outstanding at end of period	11.46	$ 12.28
Weighted Average Exercise Price, Options exercisable at end of period	$ 15.21
Weighted Average Remaining Contract Term, Options
Weighted Average Remaining Contractual Term, Options outstanding at beginning of period	7 years 8 months 12 days	8 years 8 months 12 days
Weighted Average Remaining Contractual Term, Options exercisable at end of period	6 years 1 month 6 days

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Restricted Stock Unit Activity under 2018 Plan (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Restricted Stock Units
Number of Shares, Non-Vested outstanding at beginning of period	9,000
Number of Shares, Vested/settled	(5,858)
Number of Shares, Cancelled/forfeited	(3,142)
Weighted Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value Per Share, Non-Vested outstanding at beginning of the period | $ / shares	$ 23.60

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Stock-Based Compensation Expense (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stockholders Equity [Line Items]
Stock-based compensation	$ 487,403	$ 564,024	$ 1,758,315	$ 1,951,317
Research and Development
Stockholders Equity [Line Items]
Stock-based compensation	115,817	166,289	606,470	785,423
General and Administrative
Stockholders Equity [Line Items]
Stock-based compensation	$ 371,586	$ 397,735	$ 1,151,845	$ 1,165,894

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Number of Shares of Common Stock Underlying Potentially Dilutive Securities (Details) - shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock dilutive securities	1,357,163	1,394,664
Options to purchase common stock and unvested, unsettled restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock dilutive securities	1,357,163	1,394,664

Restructuring - Additional Info

Restructuring - Additional Information (Details)	1 Months Ended	3 Months Ended
	Jun. 30, 2019Employee	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Restructuring Cost And Reserve [Line Items]
One-time severance-related charge		$ 1,500,000
Corporate restructuring, reduction of full-time workforce percentage	60.00%
Corporate restructuring, reduction of full-time workforce employees | Employee	48
One Time Employee Severance
Restructuring Cost And Reserve [Line Items]
Remaining liability			$ 0
General and Administrative
Restructuring Cost And Reserve [Line Items]
One-time severance-related charge		1,000,000
Research and Development
Restructuring Cost And Reserve [Line Items]
One-time severance-related charge		$ 500,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)	Oct. 08, 2020	Oct. 26, 2020	Sep. 30, 2020
Subsequent Event [Line Items]
Proceeds from issuance of common stock			$ 6,667,091
Subsequent Event | Lincoln Park
Subsequent Event [Line Items]
Issuance of common stock		300,000
Proceeds from issuance of common stock		$ 800,000
Weighted Average | Subsequent Event | Lincoln Park
Subsequent Event [Line Items]
Issuance of common stock, price per share		$ 2.77
At-the-Market Facility
Subsequent Event [Line Items]
Issuance of common stock			1,418,551
Proceeds from issuance of common stock			$ 5,800,000
At-the-Market Facility | Subsequent Event
Subsequent Event [Line Items]
Issuance of common stock	72,274
Proceeds from issuance of common stock	$ 200,000
At-the-Market Facility | Weighted Average
Subsequent Event [Line Items]
Issuance of common stock, price per share			$ 4.2664
At-the-Market Facility | Weighted Average | Subsequent Event
Subsequent Event [Line Items]
Issuance of common stock, price per share	$ 3.1456