Forte Biosciences (FBRX) 10-Q 15 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 12, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Interactive Data Current	Yes
Trading Symbol	FBRX
Entity Current Reporting Status	Yes
Entity Registrant Name	FORTE BIOSCIENCES, INC.
Entity Central Index Key	0001419041
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity File Number	001-38052
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1243872
Entity Address, Address Line One	3060 Pegasus Park Drive, Building 6
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75247
City Area Code	310
Local Phone Number	618-6994
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		20,340,265

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 38,548	$ 42,044
Prepaid expenses and other current assets	298	476
Total current assets	38,846	42,520
Other assets	874	786
Total assets	39,720	43,306
Current liabilities:
Accounts payable	698	946
Accrued liabilities	815	812
Total current liabilities	1,513	1,758
Commitments and contingencies (Note 4)
Stockholders’ equity
Common stock, $0.001 par value: 200,000,000 shares authorized as of June 30, 2022 (unaudited) and December 31, 2021; 14,761,261 and 14,754,447 shares issued and outstanding at June 30, 2022 (unaudited) and December 31, 2021, respectively	15	15
Additional paid-in capital	116,959	114,698
Accumulated deficit	(78,767)	(73,165)
Total stockholders’ equity	38,207	41,548
Total liabilities, convertible preferred stock and stockholders’ equity	$ 39,720	$ 43,306

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	14,761,261	14,754,447
Common stock, shares outstanding	14,761,261	14,754,447
Series A Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	10,000,000	10,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Convertible preferred stock, liquidation preference	$ 0	$ 0

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating expenses:
Research and development	$ 1,034	$ 3,523	$ 1,727	$ 6,845
General and administrative	1,986	2,224	3,807	3,643
Total operating expenses	3,020	5,747	5,534	10,488
Loss from operations	(3,020)	(5,747)	(5,534)	(10,488)
Other expenses, net	(15)	(65)	(68)	(128)
Net loss	$ (3,035)	$ (5,812)	$ (5,602)	$ (10,616)
Net loss per share - basic	$ (0.21)	$ (0.43)	$ (0.38)	$ (0.79)
Net loss per share - diluted	$ (0.21)	$ (0.43)	$ (0.38)	$ (0.79)
Weighted average shares outstanding, basic	14,761,261	13,603,181	14,760,538	13,429,018
Weighted average shares outstanding, diluted	14,761,261	13,603,181	14,760,538	13,429,018

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2020	$ 58,980	$ 13	$ 110,424	$ (51,457)
Beginning balance, shares at Dec. 31, 2020		12,830,598
Exercise of employee stock options	27		27
Exercise of employee stock options, shares		7,655
Cashless exercise of warrants, shares		673,463
Stock-based compensation	495		495
Net loss	(4,804)			(4,804)
Ending Balance at Mar. 31, 2021	54,698	$ 13	110,946	(56,261)
Ending balance, shares at Mar. 31, 2021		13,511,716
Beginning Balance at Dec. 31, 2020	58,980	$ 13	110,424	(51,457)
Beginning balance, shares at Dec. 31, 2020		12,830,598
Net loss	(10,616)
Ending Balance at Jun. 30, 2021	49,909	$ 14	111,968	(62,073)
Ending balance, shares at Jun. 30, 2021		14,079,057
Beginning Balance at Mar. 31, 2021	54,698	$ 13	110,946	(56,261)
Beginning balance, shares at Mar. 31, 2021		13,511,716
Exercise of employee stock options	15		15
Exercise of employee stock options, shares		1,939
Issuance of common stock upon vesting of restricted stock units, shares		5,000
Exercise of cashless warrants		$ 1	(1)
Cashless exercise of warrants, shares		560,402
Stock-based compensation	1,008		1,008
Net loss	(5,812)			(5,812)
Ending Balance at Jun. 30, 2021	49,909	$ 14	111,968	(62,073)
Ending balance, shares at Jun. 30, 2021		14,079,057
Beginning Balance at Dec. 31, 2021	41,548	$ 15	114,698	(73,165)
Beginning balance, shares at Dec. 31, 2021		14,754,447
Exercise of employee stock options	1		1
Exercise of employee stock options, shares		1,098
Issuance of common stock under ESPP	11		11
Issuance of common stock under ESPP, shares		5,716
Stock-based compensation	1,055		1,055
Net loss	(2,567)			(2,567)
Ending Balance at Mar. 31, 2022	40,048	$ 15	115,765	(75,732)
Ending balance, shares at Mar. 31, 2022		14,761,261
Beginning Balance at Dec. 31, 2021	$ 41,548	$ 15	114,698	(73,165)
Beginning balance, shares at Dec. 31, 2021		14,754,447
Exercise of employee stock options, shares	1,098
Net loss	$ (5,602)
Ending Balance at Jun. 30, 2022	38,207	$ 15	116,959	(78,767)
Ending balance, shares at Jun. 30, 2022		14,761,261
Beginning Balance at Mar. 31, 2022	40,048	$ 15	115,765	(75,732)
Beginning balance, shares at Mar. 31, 2022		14,761,261
Stock-based compensation	1,194		1,194
Net loss	(3,035)			(3,035)
Ending Balance at Jun. 30, 2022	$ 38,207	$ 15	$ 116,959	$ (78,767)
Ending balance, shares at Jun. 30, 2022		14,761,261

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (5,602)	$ (10,616)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense		27
Stock based compensation expense	2,249	1,503
Changes in operating assets and liabilities:
Prepaid expenses and other assets	275	399
Accounts payable	(277)	(255)
Accrued liabilities	3	974
Net cash used in operating activities	(3,352)	(7,968)
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP	12	42
Payment of deferred financing costs	(156)	(44)
Net cash used in financing activities	(144)	(2)
Net decrease in cash and cash equivalents	(3,496)	(7,970)
Cash and cash equivalents — beginning of period	42,044	58,765
Cash and cash equivalents — end of period	38,548	$ 50,795
Supplemental disclosure of non-cash investing and financing activities:
Unpaid Deferred Transaction Costs	$ 29

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Forte Biosciences, Inc. (www.fortebiorx.com) and its subsidiaries, referred to herein as the “Company”, is a biopharmaceutical company focused on developing its FB-102 program which the Company believes has potentially broad applications for autoimmune diseases. FB-102 is currently in preclinical development. The Company was incorporated in Delaware on May 3, 2017 as a privately-held company. The Company merged with Tocagen, Inc. ("Merger"), a publicly traded biotechnology company, on June 15, 2020. The Company’s common stock is traded on the Nasdaq stock exchange under the ticker symbol “FBRX.” On February 12, 2021, the Company incorporated Forte Biosciences Emerald Limited in Dublin, Ireland. This subsidiary was dissolved on April 1, 2022. Liquidity and Risks The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The condensed consolidated financial statements do not reflect any adjustments relating to the recoverability and reclassification of assets and liabilities that might be necessary if the Company is unable to continue as a going concern. Since inception, the Company has incurred losses and negative cash flows from operations. As of June 30, 2022, the Company had an accumulated deficit of $ 78.8 million . The Company used $ 3.4 million of cash in operating activities during the six months ended June 30, 2022. Management expects to continue to incur additional losses in the foreseeable future as the Company focuses its development efforts on advancing FB-102 through preclinical trials. The Company had cash and cash equivalents of approximately $ 38.5 million as of June 30, 2022. The Company’s cash and cash equivalents are held at financial institutions and exceed federally insured limits. The Company believes that its existing cash and cash equivalents will be sufficient to allow the Company to fund its operations for at least 12 months from the filing date of this Form 10-Q. The Company will continue to need to raise additional capital or obtain financing from other sources. Management may fund future operations through the sale of equity and debt financings and may also seek additional capital through arrangements with strategic partners or other sources. There can be no assurance that additional funding will be available on terms acceptable to the Company, if at all. If the Company is unable to raise additional funding to meet its working capital needs in the future, it may be forced to delay or reduce the scope of its research and development programs and/or limit or cease its operations. Our ability to raise additional funds may be adversely impacted by potential worsening global economic conditions and the recent disruptions to, and volatility in, the credit and financial markets in the United States and worldwide resulting from the conflicts in Eastern Europe, and otherwise. There are numerous risks and uncertainties associated with pharmaceutical development and the Company is unable to predict the timing or amount of increased expenses on the development of future product candidates or when or if it will start to generate revenues. Even if the Company does generate revenues, it may not be able to achieve or maintain profitability. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and may be forced to reduce its operations. The pandemic caused by outbreaks of new strains of coronaviruses, or COVID-19 and its variants, has resulted, and may continue to result, in significant national and global economic disruption and may adversely affect the Company’s operations. The Company is actively monitoring the impact of COVID-19 and the possible effects on its financial condition, liquidity, operations, suppliers, industry, and workforce. However, the full extent, consequences, and duration of the COVID-19 pandemic and the resulting impact on the Company cannot currently be predicted. The Company will continue to evaluate the impact that these events could have on its operations, financial position, results of operations and cash flows during the remainder of 2022.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements of the Company should be read in conjunction with its audited financial statements and accompanying notes thereto as of and for the year ended December 31, 2021 included in the Company’s Form 10-K as filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 31, 2022. The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), as found in the Accounting Standards Codification (“ASC”), the Accounting Standards Update (“ASU”), of the Financial Accounting Standards Board (“FASB”), and the rules and regulations of the US Securities and Exchange Commission (“SEC”). In the opinion of management, the accompanying condensed consolidated financial statements include all adjustments that are of a normal and recurring nature and that are necessary for the fair presentation of the Company’s financial position, the results of its operations and cash flows for the periods presented. Interim results are not necessarily indicative of results for the full year or any future period. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Forte Subsidiary, Inc and Forte Biosciences Emerald Limited . All intercompany accounts and transactions have been eliminated in the preparation of the condensed consolidated financial statements. Cash and Cash Equivalents Cash and cash equivalents include money market funds and deposits with commercial banks. Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less at the date of purchase. Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a three-level hierarchy that prioritizes the inputs used in determining fair value by their reliability and preferred use as follows: • Level 1 - Valuations based on quoted prices in active markets for identical assets or liabilities. • Level 2 – Valuations based on quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data. • Level 3 – Valuations based on inputs that are both significant to the fair value measurements and are unobservable. To the extent that a valuation is based on models or inputs that are less observable, or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized within Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. There have been no significant changes to the valuation methods utilized by the Company during the periods presented. There have been no transfers between Level 1, Level 2, and Level 3 in any periods presented. The carrying amounts of financial instruments consisting of cash and cash equivalents, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities included in the Company’s financial statements, are reasonable estimates of fair value, primarily due to their short maturities. The Company had $ 34.9 million in money market funds as of June 30, 2022 and December 31, 2021, which are classified within Level 1. Money market funds are valued at the closing price reported by the fund sponsor from an actively traded exchange. Money market funds were included as cash and cash equivalents in the condensed consolidated balance sheets at June 30, 2022 and December 31, 2021.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	3. Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets as of June 30, 2022 and December 31, 2021 consist of the following (in thousands): June 30, 2022 December 31, 2021 Prepaid insurance $ 204 $ 387 Other 94 89 Total prepaid expenses and other current assets $ 298 $ 476 Other Assets Other assets as of June 30, 2022 and December 31, 2021 consist of the following (in thousands): June 30, 2022 December 31, 2021 Prepaid insurance $ 570 $ 667 Prepaid offering costs 291 106 Other 13 13 Total other assets $ 874 $ 786 Accrued Liabilities Accrued liabilities as of June 30, 2022 and December 31, 2021 consist of the following (in thousands): June 30, 2022 December 31, 2021 Accrued legal and professional fees $ 102 $ 75 Accrued compensation 454 681 Accrued manufacturing and clinical expenses 208 40 Other 51 16 Total accrued liabilities $ 815 $ 812

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	4. Commitments and Contingencies Concentrations of Credit Risk Bank accounts in the United States are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $ 250,000 . The Company’s cash accounts significantly exceed FDIC limits. Indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, and employees for certain events and occurrences while the officer, or director is, or was, serving at the Company’s request in such capacity. License to Patented Technology In December 2017, the Company entered into an exclusive license agreement with the Department of Health and Human Services (“DHHS”). Under the agreement, the DHHS granted the Company an exclusive, sublicensable, worldwide license to certain patent rights under which the Company may develop and commercialize pharmaceutical and biological compositions comprising Gram-negative bacteria for the topical treatment of dermatological diseases and conditions (the “DHHS License”). The Company terminated the license agreement with DHHS effective April 2, 2022 without meeting any milestones. The Company incurred $ 0 and $ 25,000 in minimum royalty expenses for the three months ended June 30, 2022 and 2021, and $ 25,000 and $ 50,000 for the six months ended June 30, 2022 and 2021, respectively. Lease Agreements The Company has entered into month-to-month lease agreements for certain office and laboratory space. The lease agreements are cancellable by the Company at any time with a 30-day notice. Total rent expense for all locations for the three and six months ended June 30, 2022 was $ 3,000 and $ 6,000 , respectively. Total rent expense for all locations for the three months ended June 30, 2021 was $ 6,000 . The Company recorded a net rent credit of $ 9,000 for the six months ended June 30, 2021 as a result of a refund for operating expense adjustments. Preclinical Services The Company has entered into various agreements with third party vendors for preclinical services. The estimated remaining commitments as of June 30, 2022 under these agreements were approximately $ 199,000 .

Equity

Equity	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Equity	5. Equity Common Stock In February 2021, warrants to purchase 978,858 shares of common stock were exercised on a cashless basis resulting in 673,463 shares being issued. In June 2021, warrants to purchase 760,572 shares of common stock were exercised on a cashless basis resulting in 560,402 shares being issued. In September 2021, warrants to purchase 1,013,116 shares of common stock were exercised on a cashless basis resulting in 655,409 shares being issued. Warrants to purchase 4,434 shares of the Company’s common stock at an exercise price of $ 140.25 per share which were previously issued by Tocagen, Inc. survived the merger with Tocagen and remained outstanding as of June 30, 2022. In June 2021, the Company filed a shelf registration statement on Form S-3 that went effective in June 2021 which will allow the Company to raise up to $ 300 million in additional capital. The Company incurred $ 106,000 in offering costs related to this shelf registration statement which is recorded in Other Assets in the condensed consolidated balance sheet as of June 30, 2022. On March 31, 2022, the Company entered into an “at-the-market” equity offering program (“ATM Facility”) whereby the Company may from time to time offer and sell shares of its common stock up to an aggregate offering price of $ 25.0 million during the term of the ATM Facility. On April 1, 2022, the Company filed a prospectus supplement to the June 2021 Form S-3 relating to the offer and sale of the shares pursuant to the ATM Facility covering sales of up to $ 7,000,000 of shares of common stock. On August 12, 2022, the Company filed an additional prospectus supplement relating to the offer and sale of shares pursuant to the ATM Facility covering sales of up to an additional $ 2.7 million of shares of common stock. The Company is not obligated to sell any shares under the ATM Facility. The ATM Facility may be terminated at any time upon ten days’ prior notice, or at any time in certain circumstances, including the occurrence of a material adverse effect on the Company. The Company has agreed to pay the sales agent a commission equal to 3.0 % of the gross proceeds from the sales of shares under the ATM Facility and has agreed to provide the sales agent with customary indemnification and contribution rights. The Company incurred $ 185,000 in offering costs related to the ATM facility which is recorded in Other Assets in the condensed consolidated balance sheet as of June 30, 2022. The Company had not issued any shares of common stock under the ATM Facility through June 30, 2022. The Company had issued 5.6 million shares of common stock for gross proceeds of approximately $ 7.0 . million under the ATM Facility from July 1, 2022 through August 12, 2022.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	6 . Stock-Based Compensation Equity Plans In December 2018, Forte Subsidiary adopted the 2018 Equity Incentive Plan (the “2018 Incentive Plan”). The terms and conditions of stock-based awards were defined at the sole discretion of the Forte Subsidiary’s Board of Directors. Service-based awards vesting over a defined period of service and performance-based awards that vest upon the achievement of defined conditions have been issued under the 2018 Incentive Plan. Service-based awards generally vest over a four-year period, with the first 25 % of such awards vesting following twelve months of continued employment or service with the remaining awards vesting monthly in equal installments over the following thirty-six months . Stock options granted under the 2018 Incentive Plan expire ten years from the date of grant and the exercise price must be at least equal to the fair market value of common stock on the grant date. In connection with the Merger, all outstanding options under the 2018 Incentive Plan were exchanged into options to purchase common stock of Tocagen, which changed its name to Forte Biosciences Inc. upon the closing of the Merger. Subsequent to the Merger, the 2018 Incentive Plan was suspended and no more stock-based awards will be granted from that plan. In connection with the Merger, the Company assumed Tocagen’s 2017 Equity Incentive Plan, which was effective on April 12, 2017, was subsequently amended on September 30, 2018 and further amended on February 12, 2019 (the “2017 Plan”). Immediately upon closing of the Merger, 61,406 restricted stock awards and stock options to purchase 26,968 shares of common stock granted under the 2017 Plan prior to the Merger became fully vested in consideration for pre-merger services provided to Tocagen. On July 26, 2020, the Company adopted the 2020 Inducement Equity Incentive Plan (the “2020 Inducement Plan”) and reserved 500,000 shares for future grants under the 2020 Inducement Plan. As of June 30, 2022 , there were 115,000 shares available for issuance under the 2020 Inducement Plan. In May 2021, the 2017 Plan was terminated and replaced by the 2021 Equity Incentive Plan (the “2021 Plan”). The 2021 Plan had an initial reserve of 1,000,000 shares available for grant. The 2021 Plan was amended in June 2022 to increase the shares available for grant by an additional 1,500,000 shares. The 2021 Plan provides for the grant of incentive stock options (“ISOs”), non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards, other forms of equity compensation and performance cash awards. ISOs may be granted only to employees. All other awards may be granted to employees, including officers, and to non-employee directors and consultants of the Company and its affiliates. Subsequent to the Merger, service-based awards generally vested over a four-year period, with the first 25 % of such awards vesting following twelve months of continued employment or service with the remaining awards vesting monthly in equal installments over the following thirty-six months . For certain service-based awards to the board of directors, vesting occurs in thirty-six equal monthly installments over a three-year period for initial grants and in twelve equal monthly installments over a twelve-month period for subsequent grants . As of June 30, 2022 , there were 1,361,736 shares available for issuance under the 2021 Plan. Stock Options The risk-free interest rate valuation assumption for options is based on the U.S. Treasury yield curve rate at the date of grant with a maturity approximating the expected term of the option. The expected term assumption for options granted to employees is determined using the simplified method that represents the average of the contractual term of the option and the weighted average vesting period of the option. The Company uses the simplified method because it does not have sufficient historical option exercise data to provide a reasonable basis upon which to estimate expected term. Due to the Company’s limited trading of its common stock and lack of company-specific historical or implied volatility data, the Company has based its estimate of expected volatility on the historical volatility of a group of similar companies in the life sciences industry whose shares are publicly traded. The Company selects the peer group based on comparable characteristics, including development stage, product pipeline, and enterprise value. The Company computes historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. The assumed dividend yield is based upon the Company’s expectation of not paying dividends in the foreseeable future. Prior to the Merger, the fair value per share was determined by the Company’s Board of Directors, as of the date of each grant based on independent third-party valuations, taking into consideration various objective and subjective factors. Subsequent to the Merger, the fair value per share is the closing stock price on the option grant date. The weighted average grant-date fair value of stock options granted in the three and six months ended June 30, 2022 was $ 0.82 and $ 0.92 , and $ 23.40 and $ 23.29 in the three and six months ended June 30, 2021, respectively. The weighted-average assumptions used to value these stock options using the Black-Scholes option-pricing model were as follows. Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Fair value of common stock $ 1.28 $ 38.14 $ 1.49 $ 37.89 Risk-free interest rate 3.06 % 1.03 % 2.25 % 0.96 % Dividend yield 0.00 % 0.00 % 0.00 % 0.00 % Expected term of options (years) 5.78 5.84 5.88 5.89 Volatility 71.45 % 69.70 % 68.57 % 69.80 % The table below summarizes the stock option activity during the six months ended June 30, 2022: Number of Weighted- Weighted- Aggregate Balances at December 31, 2021 1,281,396 $ 18.18 7.94 Granted 1,149,166 $ 1.49 Exercised ( 1,098 ) $ 1.06 $ - Cancelled/Forfeited ( 90,728 ) $ 31.80 Balances at June 30, 2022 2,338,736 $ 9.46 8.59 $ 218 Vested and expected to vest at June 30, 2022 2,338,736 $ 9.46 8.59 $ 218 Exercisable at June 30, 2022 361,666 $ 22.41 7.88 $ 16 The aggregate intrinsic value of options at June 30, 2022 is based on the Company’s fair value of its stock price on that date of $ 1.30 per share. Restricted Stock Unit Awards There were no restricted stock units granted during the six months ended June 30, 2022. The Company made a change in accounting estimate in the three months ended March 31, 2022 related to the vesting of performance-based restricted stock units. As a result of this change in accounting estimate, $ 158,000 of expense that had been previously recognized in 2021 was reversed in the three months ended March 31, 2022. Restricted stock unit awards outstanding as of June 30, 2022 were as follows: Weighted Avg Grant Date Shares Fair Value Outstanding at December 31, 2021 258,851 $ 3.36 Granted — — Forfeited/Cancelled — — Issued as Common Stock — — Outstanding at June 30, 2022 258,851 $ 3.36 2017 Employee Stock Purchase Plan In May 2021, the Company’s board of directors reactivated the Company’s 2017 Employee Stock Purchase Plan (“ESPP”) which had previously been suspended. The ESPP allows eligible employees to withhold up to 15 % of their earnings to purchase shares of the Company’s common stock at a price per share equal to the lower of (i) 85 % of the fair market value of a share of the Company’s common stock on the first date of an offering or (ii) 85 % of the fair market value of a share of the Company’s common stock on the date of purchase. The Company had 170,978 shares available for future issuance under the ESPP as of June 30, 2022 . The number of shares of common stock reserved for issuance will automatically increase on January 1 of each calendar year through January 1, 2027, by the lesser of (a) 1 % of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (b) 300,000 shares, or (c) a number determined by the Company’s board of directors that is less than (a) and (b). The Company issued 5,716 shares under the ESPP during the six months ended June 30, 2022. The ESPP is considered a compensatory plan. The Company did not record stock-based compensation expense with its ESPP for the three or six months ended June 30, 2022 or 2021. Stock-Based Compensation Expense Stock-based compensation expenses included in the Company’s condensed consolidated statements of operations for the three and six months ended June 30, 2022 and 2021 were (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Research and development $ 380 $ 364 $ 666 $ 668 General and administrative 814 644 1,583 835 Total $ 1,194 $ 1,008 $ 2,249 $ 1,503 As of June 30, 2022 , there was unrecognized stock-based compensation expense related to stock options with service conditions of $ 8.0 million, which is expected to be recognized over a weighted-average period of 2.56 years. Total unrecognized stock-based compensation expenses related to stock options and restricted stock units with performance conditions were approximately $ 284,000 .

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	7. Related Party Transactions One member of the Company’s board of directors received cash payments of $ 5,000 for scientific consulting services during the three months ended March 31, 2022 and another member of the Company’s board of directors received cash payments of $ 7,000 for scientific consulting services during the three months ended June 30, 2022. The payment related to the scientific consulting services performed during the three months ended June 30, 2022 remained outstanding as of June 30, 2022. There were no related party transactions during the three and six months ended June 30, 2021.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	8. Subsequent Events Rights Plan On July 11, 2022, the Company authorized and declared a dividend distribution of one right (each, a “Right”) for each outstanding share of common stock of the Company to stockholders of record as of the close of business on July 21, 2022 . Each Right entitles the registered holder to purchase from the Company one one-thousandth of a share of Series A Participating Preferred Stock, par value $ 0.001 per share (the “Preferred Stock”), of the Company at an exercise price of $ 16.00 per one one-thousandth of a share of Preferred Stock, subject to adjustment. The complete terms of the Rights are set forth in a Preferred Stock Rights Agreement (the “Rights Agreement”). The Board adopted the Rights Agreement to protect stockholders from coercive or otherwise unfair takeover tactics. In general terms, the Rights Agreement works by imposing a significant penalty upon any person or group that acquires 10 percent or more (or 20 percent or more in the case of certain institutional investors who report their holdings on Schedule 13G) of the Common Stock without the approval of the Board. As a result, the overall effect of the Rights Agreement and the issuance of the Rights may be to render more difficult or discourage a merger, tender or exchange offer or other business combination involving the Company that is not approved by the Board. However, neither the Rights Agreement nor the Rights should interfere with any merger, tender or exchange offer or other business combination approved by the Board.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements of the Company should be read in conjunction with its audited financial statements and accompanying notes thereto as of and for the year ended December 31, 2021 included in the Company’s Form 10-K as filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 31, 2022. The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), as found in the Accounting Standards Codification (“ASC”), the Accounting Standards Update (“ASU”), of the Financial Accounting Standards Board (“FASB”), and the rules and regulations of the US Securities and Exchange Commission (“SEC”). In the opinion of management, the accompanying condensed consolidated financial statements include all adjustments that are of a normal and recurring nature and that are necessary for the fair presentation of the Company’s financial position, the results of its operations and cash flows for the periods presented. Interim results are not necessarily indicative of results for the full year or any future period.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Forte Subsidiary, Inc and Forte Biosciences Emerald Limited . All intercompany accounts and transactions have been eliminated in the preparation of the condensed consolidated financial statements.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include money market funds and deposits with commercial banks. Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less at the date of purchase.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a three-level hierarchy that prioritizes the inputs used in determining fair value by their reliability and preferred use as follows: • Level 1 - Valuations based on quoted prices in active markets for identical assets or liabilities. • Level 2 – Valuations based on quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data. • Level 3 – Valuations based on inputs that are both significant to the fair value measurements and are unobservable. To the extent that a valuation is based on models or inputs that are less observable, or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized within Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. There have been no significant changes to the valuation methods utilized by the Company during the periods presented. There have been no transfers between Level 1, Level 2, and Level 3 in any periods presented. The carrying amounts of financial instruments consisting of cash and cash equivalents, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities included in the Company’s financial statements, are reasonable estimates of fair value, primarily due to their short maturities. The Company had $ 34.9 million in money market funds as of June 30, 2022 and December 31, 2021, which are classified within Level 1. Money market funds are valued at the closing price reported by the fund sponsor from an actively traded exchange. Money market funds were included as cash and cash equivalents in the condensed consolidated balance sheets at June 30, 2022 and December 31, 2021.
Use of Estimates	Use of Estimates The preparation of the Company’s condensed consolidated financial statements requires management to make estimates and assumptions that impact the reported amounts of assets, liabilities, expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes. Significant management estimates that affect the reported amounts of assets, liabilities and expenses include stock-based compensation expense, accruals and deferred tax assets. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development costs consist primarily of salaries and benefits of research and development personnel, costs related to research activities, preclinical studies, clinical trials and drug manufacturing. Non-refundable advance payments for goods or services that will be used in future research and development activities are deferred and capitalized and are only expensed when the goods have been received or when the service has been performed rather than when the payment is made. Drug manufacturing, clinical and preclinical costs are a component of research and development expenses. The Company expenses costs for its drug manufacturing activities performed by Contract Manufacturing Organizations (“CMOs”), preclinical and clinical trial costs performed by Contract Research Organizations (“CROs”) and other service providers, as they are incurred, based upon estimates of the work completed over the life of the individual study in accordance with associated agreements. The Company uses information it receives from internal personnel and outside service providers to estimate the percentage of completion and therefore the expense to be incurred.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss and other comprehensive income (loss) for the period. The Company did no t have other comprehensive income (loss) items such as unrealized gains and losses. Comprehensive loss was equal to net loss for the three and six months ended June 30, 2022 and 2021 .
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing net loss by the weighted-average number of shares of common stock and common stock equivalents outstanding during the period in accordance with the treasury stock method. The following number of unexercised stock options, warrants and restricted stock units, which are common stock equivalents, have been excluded from the diluted net loss calculation as their effect would have been anti-dilutive for all periods presented: Three and Six Months Ended June 30, 2022 2021 Options 2,338,736 1,395,904 Restricted stock units 258,851 15,000 Warrants 4,434 1,017,550 Total 2,602,021 2,428,454
Recently Issued Accounting Standards Not Yet Adopted	Recently Issued Accounting Standards Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by us as of a specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations. In August 2020, the FASB issued ​ASU 2020-06​, ​Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in an Entity’s Own Equity (Subtopic 815-40)​ (“ASU 2020-06”). ​ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted earnings per share computation. The amendments in ASU 2020-06 are effective for smaller reporting companies as defined by the SEC for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but not earlier than fiscal years beginning after December 15, 2020. The Company is currently evaluating the impact of ASU 2020-06 on its condensed consolidated financial statements and does not expect the adoption of this amended guidance to have a material impact on the Company’s condensed consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Schedule of Common Stock Equivalents Excluded from Diluted Net Loss Calculation	The following number of unexercised stock options, warrants and restricted stock units, which are common stock equivalents, have been excluded from the diluted net loss calculation as their effect would have been anti-dilutive for all periods presented: Three and Six Months Ended June 30, 2022 2021 Options 2,338,736 1,395,904 Restricted stock units 258,851 15,000 Warrants 4,434 1,017,550 Total 2,602,021 2,428,454

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets as of June 30, 2022 and December 31, 2021 consist of the following (in thousands): June 30, 2022 December 31, 2021 Prepaid insurance $ 204 $ 387 Other 94 89 Total prepaid expenses and other current assets $ 298 $ 476
Schedule of Other Assets	Other assets as of June 30, 2022 and December 31, 2021 consist of the following (in thousands): June 30, 2022 December 31, 2021 Prepaid insurance $ 570 $ 667 Prepaid offering costs 291 106 Other 13 13 Total other assets $ 874 $ 786
Components of Accrued Liabilities	Accrued liabilities as of June 30, 2022 and December 31, 2021 consist of the following (in thousands): June 30, 2022 December 31, 2021 Accrued legal and professional fees $ 102 $ 75 Accrued compensation 454 681 Accrued manufacturing and clinical expenses 208 40 Other 51 16 Total accrued liabilities $ 815 $ 812

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Weighted-Average Assumptions Used to Value Stock Options	The weighted-average assumptions used to value these stock options using the Black-Scholes option-pricing model were as follows. Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Fair value of common stock $ 1.28 $ 38.14 $ 1.49 $ 37.89 Risk-free interest rate 3.06 % 1.03 % 2.25 % 0.96 % Dividend yield 0.00 % 0.00 % 0.00 % 0.00 % Expected term of options (years) 5.78 5.84 5.88 5.89 Volatility 71.45 % 69.70 % 68.57 % 69.80 %
Summary of Stock Option Activity	The table below summarizes the stock option activity during the six months ended June 30, 2022: Number of Weighted- Weighted- Aggregate Balances at December 31, 2021 1,281,396 $ 18.18 7.94 Granted 1,149,166 $ 1.49 Exercised ( 1,098 ) $ 1.06 $ - Cancelled/Forfeited ( 90,728 ) $ 31.80 Balances at June 30, 2022 2,338,736 $ 9.46 8.59 $ 218 Vested and expected to vest at June 30, 2022 2,338,736 $ 9.46 8.59 $ 218 Exercisable at June 30, 2022 361,666 $ 22.41 7.88 $ 16
Summary of Restricted Stock Unit Award Transactions	Restricted stock unit awards outstanding as of June 30, 2022 were as follows: Weighted Avg Grant Date Shares Fair Value Outstanding at December 31, 2021 258,851 $ 3.36 Granted — — Forfeited/Cancelled — — Issued as Common Stock — — Outstanding at June 30, 2022 258,851 $ 3.36
Summary of Stock-Based Compensation Expenses	Stock-based compensation expenses included in the Company’s condensed consolidated statements of operations for the three and six months ended June 30, 2022 and 2021 were (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Research and development $ 380 $ 364 $ 666 $ 668 General and administrative 814 644 1,583 835 Total $ 1,194 $ 1,008 $ 2,249 $ 1,503

Organization and Description _2

Organization and Description of Business - Additional Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2022	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Accumulated deficit		$ 78,767		$ 73,165
Cash used in operating activities		(3,352)	$ (7,968)
Cash and cash equivalents		$ 38,548		$ 42,044
Tocagen, Inc.
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Reverse split ratio	0.06667

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Schedule Of Significant Accounting Policies [Line Items]
Transfers between fair value hierarchy levels	$ 0		$ 0
Other comprehensive income (loss)	0	$ 0	0	$ 0
Level 1
Schedule Of Significant Accounting Policies [Line Items]
Money market funds, at carrying value	$ 34,900,000		$ 34,900,000		$ 34,900,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Common Stock Equivalents Excluded from Diluted Net Loss Calculation (Details) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss calculation	2,602,021	2,428,454
Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss calculation	2,338,736	1,395,904
Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss calculation	4,434	1,017,550
Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss calculation	258,851	15,000

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Prepaid insurance	$ 204	$ 387
Other	94	89
Total prepaid expenses and other current assets	$ 298	$ 476

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Prepaid insurance	$ 570	$ 667
Prepaid offering costs	291	106
Other	13	13
Total other assets	$ 874	$ 786

Balance Sheet Components - Comp

Balance Sheet Components - Components of Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued legal and professional fees	$ 102	$ 75
Accrued compensation	454	681
Accrued manufacturing and clinical expenses	208	40
Other	51	16
Total accrued liabilities	$ 815	$ 812

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Commitments And Contingencies [Line Items]
FDIC insured amount	$ 250,000		$ 250,000
Royalty expenses	0	$ 25,000	25,000	$ 50,000
Rent expenses	3,000	$ 6,000	6,000
Rent credit due to refund for operating expense adjustments				$ 9,000
Contractual Obligation	$ 199,000		$ 199,000

Equity - Additional Information

Equity - Additional Information (Details) - USD ($)				1 Months Ended				6 Months Ended
	Aug. 12, 2022	Apr. 01, 2022	Mar. 31, 2022	Aug. 12, 2022	Sep. 30, 2021	Jun. 30, 2021	Feb. 28, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Jun. 16, 2020
Class Of Stock [Line Items]
Offering costs								$ 156,000	$ 44,000
Shelf Registration
Class Of Stock [Line Items]
Offering costs								106,000
Shelf Registration | Maximum
Class Of Stock [Line Items]
Additional capital raised								300,000,000
At The Market Equity Offering Program
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock			$ 25,000,000
Offering costs								$ 185,000
Percentage of sales commission			3%
At The Market Equity Offering Program | Maximum
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock		$ 7,000,000
At The Market Equity Offering Program | Maximum | Subsequent Event
Class Of Stock [Line Items]
New issuance of common stock	$ 2,700,000
Common Stock
Class Of Stock [Line Items]
Common stock issued, shares					655,409	560,402	673,463
Warrants to purchase common stock					1,013,116	760,572	978,858		760,572		4,434
Common stock exercise price											$ 140.25
Common Stock | At The Market Equity Offering Program | Subsequent Event
Class Of Stock [Line Items]
Common stock issued, shares				5,600,000
Gross proceeds from issuance of common stock				$ 7,000,000
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued								0		0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)		1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 15, 2020	May 31, 2021	Dec. 31, 2018	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Jul. 26, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted						1,149,166
Weighted average grant-date fair value of stock options granted				$ 0.82	$ 23.40	$ 0.92	$ 23.29
Fair value of stock price						$ 1.30
Unrecognized compensation expense				$ 8,000,000		$ 8,000,000
Weighted-average period over which unrecognized compensation expense is expected to be recognized						2 years 6 months 21 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards granted						0
Unrecognized compensation expense				158,000		$ 158,000
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense				$ 284,000		$ 284,000
2018 Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service-based awards, vesting period			4 years
Stock options, expiration term			10 years
Service-based awards vesting description						vest over a four-year period, with the first 25% of such awards vesting following twelve months of continued employment or service with the remaining awards vesting monthly in equal installments over the following thirty-six months
2018 Incentive Plan | Following Twelve Months of Service
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service-based awards vesting percentage			25%
2017 Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted	26,968
2017 Incentive Plan | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards granted	61,406
2020 Inducement Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future grant								500,000
Shares available for issuance				115,000		115,000
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service-based awards, vesting period		4 years
Service-based awards vesting description						vested over a four-year period, with the first 25% of such awards vesting following twelve months of continued employment or service with the remaining awards vesting monthly in equal installments over the following thirty-six months
Shares available for issuance		1,000,000		1,361,736		1,361,736
Additional shares available for grant				1,500,000		1,500,000
2021 Equity Incentive Plan | Board of Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service-based awards, vesting period		3 years				12 months
Service-based awards vesting description						vesting occurs in thirty-six equal monthly installments over a three-year period for initial grants and in twelve equal monthly installments over a twelve-month period for subsequent grants
2021 Equity Incentive Plan | Following Twelve Months of Service
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service-based awards vesting percentage		25%
2017 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Eligible employees withhold percentage of earnings to purchase shares of common stock		15%
Shares available for future issuance				170,978		170,978
Shares reserved for issuance increase percentage of total number of shares of common stock outstanding		1%
Shares Issued under plan						5,716
2017 Employee Stock Purchase Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance increase on of each calendar year		300,000
2017 Employee Stock Purchase Plan | On First Date of Offering | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair market value of share of common stock to purchase		85%
2017 Employee Stock Purchase Plan | On Date of Purchase | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair market value of share of common stock to purchase		85%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Weighted-Average Assumptions Used to Value Stock Options (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-Based Payment Arrangement [Abstract]
Fair value of common stock	$ 1.28	$ 38.14	$ 1.49	$ 37.89
Risk-free interest rate	3.06%	1.03%	2.25%	0.96%
Dividend yield	0%	0%	0%	0%
Expected term of options (years)	5 years 9 months 10 days	5 years 10 months 2 days	5 years 10 months 17 days	5 years 10 months 20 days
Volatility	71.45%	69.70%	68.57%	69.80%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Number of Shares Outstanding
Outstanding, Beginning	1,281,396
Granted	1,149,166
Exercised	(1,098)
Cancelled/Forfeited	(90,728)
Outstanding, Ending	2,338,736	1,281,396
Vested and expected to vest	2,338,736
Exercisable	361,666
Weighted-Average Exercise Price
Outstanding, Beginning	$ 18.18
Granted	1.49
Exercised	1.06
Cancelled/Forfeited	31.80
Outstanding, Ending	9.46	$ 18.18
Vested and expected to vest	9.46
Exercisable	$ 22.41
Weighted-Average Remaining Contractual Term (Years)
Outstanding	8 years 7 months 2 days	7 years 11 months 8 days
Vested and expected to vest	8 years 7 months 2 days
Exercisable	7 years 10 months 17 days
Aggregate Intrinsic Value
Outstanding	$ 218
Vested and expected to vest	218
Exercisable	$ 16

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Restricted Stock Unit Award Transactions (Details) - Restricted Stock Units (RSUs)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Shares
Outstanding at December 31, 2021	258,851
Stock awards granted	0
Outstanding at June 30, 2022	258,851
Weighted Avg Grant Date Fair Value
Outstanding at December 31, 2021 | $ / shares	$ 3.36
Outstanding at June 30, 2022 | $ / shares	$ 3.36

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 1,194	$ 1,008	$ 2,249	$ 1,503
Research and Developments Expenses
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	380	364	666	668
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 814	$ 644	$ 1,583	$ 835

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2021
Director
Related Party Transaction [Line Items]
Payments for scientific consulting services	$ 7,000	$ 5,000
Director One
Related Party Transaction [Line Items]
Related party transactions			$ 0	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information - (Details)	Jul. 11, 2022 Right $ / shares shares	Jun. 16, 2020 $ / shares
Common Stock
Subsequent Event [Line Items]
Rights, exercise price per share		$ 140.25
Subsequent Event
Subsequent Event [Line Items]
Dividend payable, date of record	Jul. 21, 2022
Subsequent Event | Rights Agreement
Subsequent Event [Line Items]
Percentage imposing significant penalty upon any person or group acquires	10%
Percentage imposing significant penalty upon institutional investors	20%
Subsequent Event | Series A Participating Preferred Stock
Subsequent Event [Line Items]
Dividend distribution, each right entitled to purchase shares | shares	0.001
Preferred stock, par value per share	$ 0.001
Rights, exercise price per share	$ 16
Subsequent Event | Common Stock
Subsequent Event [Line Items]
Dividend distribution, number of right for each share | Right	1