0000950170-23-021320 | 10-Q | XBRL Viewer

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Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2023	May 05, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2023
Document Period End Date	Mar. 31, 2023
Current Fiscal Year End Date	--12-31
Entity Registrant Name	THIRD HARMONIC BIO, INC.
Entity Central Index Key	0001923840
Entity File Number	001-41498
Entity Tax Identification Number	83-4553503
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Incorporation, State or Country Code	DE
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Address, Address Line One	1700 Montgomery Street
Entity Address, Address Line Two	Suite 210
Entity Address, State or Province	CA
Entity Address City Or Town	San Francisco
Entity Address, Postal Zip Code	94111
City Area Code	209
Local Phone Number	727-2457
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Entity Common Stock, Shares Outstanding		40,364,375
Trading Symbol	THRD
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 282,202,000	$ 288,877,000
Prepaid expenses and other current assets	3,544,000	3,958,000
Total current assets	285,746,000	292,835,000
Restricted cash	441,000	441,000
Property and equipment, net	60,000	35,000
Right of use asset	4,258,000	4,327,000
Other assets	882,000	1,037,000
Total assets	291,387,000	298,675,000
Current liabilities:
Accounts payable	2,670,000	2,087,000
Accrued expenses and other current liabilities	1,609,000	3,181,000
Operating lease liability, current	668,000	385,000
Total current liabilities	4,947,000	5,653,000
Operating lease liability, noncurrent	3,775,000	3,954,000
Total liabilities	8,722,000	9,607,000
Commitments and contingencies (Note 12)
Stockholders’ deficit:
Common stock, $0.0001 par value, 500,000,000 shares authorized at December 31, 2022 and March 31, 2023; 39,377,222 and 39,484,403 shares issued and outstanding at December 31, 2022 and March 31, 2023, respectively	4,000	4,000
Additional paid-in capital	375,142,000	372,460,000
Accumulated deficit	(92,481,000)	(83,396,000)
Total stockholders' (deficit) equity	282,665,000	289,068,000
Total liabilities and stockholders' (deficit) equity	$ 291,387,000	$ 298,675,000

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	500,000,000	500,000,000
Common stock issued (in shares)	39,484,403	39,377,222
Common Stock, Shares, Outstanding	39,484,403	39,377,222

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating expenses:
Research and development	$ 6,737	$ 6,212
General and administrative	5,251	1,575
Total operating expenses	11,988	7,787
Loss from operations	11,988	7,787
Other income, net:
Other income	(2,903)	(3)
Total other income, net	(2,903)	(3)
Net loss	$ 9,085	$ 7,784
Net loss per share of common stock, basic	$ 0.40	$ 0.81
Net loss per share of common stock, diluted	$ 0.40	$ 0.81
Weighted-average common stock outstanding, basic	22,792,781	9,643,963
Weighted-average common stock outstanding, diluted	22,792,781	9,643,963

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock Series A-1 Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Series A-2 Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Series A-3 Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Series B Redeemable Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ (46,706)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	$ 1,534	$ (48,241)
Beginning balance, shares at Dec. 31, 2021		13,970,000	13,750,000	7,812,501	14,091,686	4,237,290
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	84,024
Stock-based compensation expense	450	$ 0	$ 0	$ 0	$ 0	$ 0	450	0
Net loss	(7,784)	0	0	0	0	0	0	(7,784)
Ending balance at Mar. 31, 2022	(54,040)	$ 12,574	$ 19,476	$ 33,288	$ 104,846	$ 1	1,984	(56,025)
Ending balance, shares at Mar. 31, 2022		13,970,000	13,750,000	7,812,501	14,091,686	4,321,314
Beginning balance at Dec. 31, 2022	289,068	$ 0	$ 0	$ 0	$ 0	$ 4	372,460	(83,396)
Beginning balance, shares at Dec. 31, 2022		0	0	0	0	39,377,222
Vesting of restricted stock	0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0
Vesting of restricted stock, shares		0	0	0	0	107,181
Stock-based compensation expense	2,682	$ 0	$ 0	$ 0	$ 0	$ 0	2,682	0
Net loss	(9,085)	0	0	0	0	0	0	(9,085)
Ending balance at Mar. 31, 2023	$ 282,665	$ 0	$ 0	$ 0	$ 0	$ 4	$ 375,142	$ (92,481)
Ending balance, shares at Mar. 31, 2023		0	0	0	0	39,484,403

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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+ Details

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (9,085)	$ (7,784)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,682	450
Depreciation expense	3	0
Noncash operating lease expense	69	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	413	(88)
Other assets	155	(69)
Accounts payable	571	(202)
Accrued expenses and other current liabilities	(1,587)	(420)
Changes in operating lease liabilities	104	0
Net cash used in operating activities	(6,675)	(8,113)
Cash flows from investing activities:
Purchase of property and equipment	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities:
Net cash provided by financing activities	0	0
Net increase in cash, cash equivalents and restricted cash	(6,675)	(8,113)
Cash, cash equivalents and restricted cash at beginning of period	289,318	128,280	$ 128,280
Cash, cash equivalents and restricted cash at end of period	282,643	120,167	$ 289,318
Supplemental disclosure of cash flows:
Fixed assets recorded in accounts payable and accrued expenses	$ 27	$ 0

Nature of the Business

3 Months Ended

Mar. 31, 2023

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of the Business

1. Nature of the Business

Third Harmonic Bio, Inc., or the Company, is a biopharmaceutical company focused on advancing the next wave of medicine for the treatment of inflammatory disease, including dermal, respiratory, and gastrointestinal diseases.

The Company was incorporated in 2019 as a Delaware corporation, and it has two offices located in San Francisco, California and Cambridge, Massachusetts. In December 2021, the Company formed THB MS, Inc., a Delaware corporation and wholly-owned subsidiary of the Company, which is classified as a Security Corporation in Massachusetts.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, completion and success of clinical testing, development by competitors of new technological innovations, compliance with governmental regulations, dependence on key personnel and protection of proprietary technology and the ability to secure additional capital to fund operations. The development of a drug candidate requires extensive research, development and clinical testing prior to regulatory approval and commercialization. These efforts require significant amounts of additional capital, adequate personnel, and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

Initial public offering

On September 19, 2022, the Company closed its initial public offering, or the IPO, and issued 12,535,000 shares of common stock, including the exercise in full by the underwriters of their option to purchase up to 1,635,000 additional shares of common stock, at a public offering price of $17.00 per share. The Company received $198.2 million, net of underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were $2.3 million. Immediately prior to the closing of the IPO, all outstanding shares of redeemable convertible preferred stock converted into 21,967,316 shares of common stock (see Note 7). In connection with the closing of its IPO, on September 19, 2022, the Company amended its certificate of incorporation to authorize the issuance of up to 500,000,000 shares of $0.0001 par value common stock and 10,000,000 shares of $0.0001 par value preferred stock.

Reverse stock split

On September 7, 2022, the Company effected a 1-for-2.259 reverse stock split of the Company’s outstanding common stock. All common stock, stock options and per share information presented in the condensed consolidated financial statements have been adjusted to reflect the reverse stock split on a retroactive basis for all periods presented. There was no change in the par value of the Company’s common stock. The ratio by which shares of preferred stock are convertible into shares of common stock was adjusted to reflect the effects of the reverse stock split.

Liquidity

In accordance with Accounting Standards Codification, or ASC 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the accompanying condensed consolidated financial statements were issued.

As an emerging growth entity, the Company has devoted substantially all of its resources since inception to organizing and staffing the Company, business planning, raising capital, establishing its intellectual property portfolio, acquiring or discovering product candidates, research and development activities for an oral KIT inhibitor and other compounds, establishing arrangements with third parties for the manufacture of its product candidates and component materials, and providing general and administrative support for these operations. As a result, the Company has incurred significant operating losses and negative cash flows from operations since its inception and anticipates such losses and negative cash flows will continue for the foreseeable future.

Since its inception, the Company has funded its operations primarily with proceeds from sales of shares of its redeemable convertible preferred stock and most recently with proceeds from the IPO. The Company has incurred recurring losses since its inception, including net losses of $7.8 million and $9.1 million and for the three months ended March 31, 2022 and 2023, respectively. As of March 31, 2023, the Company had an accumulated deficit of $92.5 million. To date the Company has not generated any revenues and expects to continue to generate operating losses for the foreseeable future. As of the issuance date of these condensed consolidated financial statements, the Company expects that its existing cash and cash equivalents of $282.2 million as of March 31, 2023, will be sufficient to fund its operating expenses and capital expenditure requirements for at least the next 12 months from the issuance date of these condensed consolidated financial statements.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The Company’s significant accounting policies are disclosed in the audited consolidated annual financial statements for the years ended December 31, 2022, and notes thereto, which are included in the Company's Annual Report on Form 10-K that was filed with the Securities and Exchange Commission on March 29, 2023. Since the date of those annual financial statements, there have been no changes to the Company’s significant accounting policies, except as noted below.

Unaudited Interim Financial Information

The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, for interim financial reporting and as required by Regulation S-X, Rule 10-01. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated annual financial statements for the years ended December 31, 2021 and 2022 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s condensed consolidated balance sheet as of March 31, 2023, the condensed consolidated statements of operations for the three months ended March 31, 2022 and 2023, the condensed consolidated statement of stockholders' equity (deficit) as of March 31, 2023 and condensed consolidated statements of cash flows for the three months ended March 31, 2022 and 2023. The financial data and other information disclosed in these notes related to the three months ended March 31, 2022 and 2023 are unaudited. The results for the three months ended March 31, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period.

Recently Issued Accounting Pronouncements Not Yet Adopted

Management evaluated recently issued accounting pronouncements and does not believe that any of these pronouncements will have a significant impact on the condensed consolidated financial statements and related disclosures.

Fair Value Measurements

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The following tables present information about the Company’s financial assets measured at fair value on a recurring basis (in thousands):


			December 31, 2022
Description	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Observable Inputs (Level 3)
Money market funds	$	286,580	$	286,580	$	—	$	—
Total financial assets	$	286,580	$	286,580	$	—	$	—


			March 31, 2023
Description	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Observable Inputs (Level 3)
Money market funds	$	280,812	$	280,812	$	—	$	—
Total financial assets	$	280,812	$	280,812	$	—	$	—

As of December 31, 2022 and March 31, 2023, the Company had no financial liabilities that required fair value measurement. As of December 31, 2022 and March 31, 2023, the Company’s cash equivalents consisted of money market funds, classified as Level 1 financial assets, as these assets are valued using quoted market prices in active markets without any valuation adjustment.

During the year ended December 31, 2022 and three months ended March 31, 2023 there were no transfers or reclassifications between fair value measurement levels of assets or liabilities. The carrying values of prepaid and other current assets, accounts payable and accrued expenses and other current liabilities approximate their fair values due to the short-term nature of these assets and liabilities.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Property, Plant and Equipment

3 Months Ended

Mar. 31, 2023

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

4. Property, Plant and Equipment

Property, plant and equipment consisted of the following (in thousands):


	December 31, 2022			March 31, 2023
Construction in progress	$	16		$	—
Leasehold Improvement		—			12
Computer equipment		20			51
Property, plant and equipment, gross		36			63
Less: Accumulated depreciation		(1	)		(3	)
Property, plant and equipment, net	$	35		$	60

Depreciation expense was $1.0 thousand for the year ended December 31, 2022 and $3.0 thousand for three months ended March 31, 2023, which has been recorded within general and administrative expenses.

Accrued Expenses and Other Current Liabilities

3 Months Ended

Mar. 31, 2023

Payables And Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

5. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2022		March 31, 2023
Accrued research and development expenses	$	1,444	$	705
Professional fees		339		124
Employee compensation and related benefits		1,165		754
Other		233		26
Total accrued expenses and other current liabilities	$	3,181	$	1,609

Novartis License Agreement

3 Months Ended

Mar. 31, 2023

License Agreement [Abstract]

Novartis License Agreement

6. Novartis License Agreement

On June 28, 2019, the Company entered into a License Agreement, or the Novartis License Agreement, with Novartis Pharma AG, formerly known as Novartis International Pharmaceutical Ltd, or Novartis. Pursuant to the Novartis License Agreement, the Company has been granted an exclusive, worldwide, royalty-bearing, sublicensable license under specified patent rights and know-how related to two licensed compounds, to develop, make, use and sell certain products incorporating or comprising a licensed compound, including THB001, to certain intellectual property rights owned or controlled by Novartis, or the Licensed IP, to research, develop, make, use, sell, and commercialize products containing the Licensed IP.

Under the Novartis License Agreement, the Company is solely responsible for all research, development, regulatory and commercialization activities related to the Licensed IP. The Company is required to use commercially reasonable efforts to develop and seek regulatory approval for, and commercialize, at least one licensed product in each of the United States, France, Germany, Italy, Spain, the United Kingdom, and Japan.

In exchange for these rights, the Company made an upfront cash payment of $0.4 million and issued 3,449,808 shares of Series A-1 Preferred Stock with a fair value of $3.0 million to Novartis. Upon entering into the Novartis License Agreement in 2019, the total initial consideration of $3.4 million transferred to Novartis was charged to expenses as research and development expense. The Company determined that the Novartis License Agreement represented an asset acquisition as it did not meet the definition of a business. The Company recorded the initial consideration transferred to Novartis as research and development expense in the statement of operations because the acquired Licensed IP represented in-process research and development with no alternative future use.

In addition, under the Novartis License Agreement, an anti-dilution right was issued to Novartis, in which Novartis is entitled to receive shares of Series A-1 Preferred Stock, guaranteeing them a 15% ownership interest of the fully diluted capitalization of the Company. The Company was obligated to issue additional shares of Series A-1 Preferred Stock until the Company had (1) raised aggregate cumulative proceeds of $30.0 million from sales of equity securities since its inception; or (2) issued and sold any securities that generate proceeds in excess of $30.0 million. Additionally, the Company was not obligated to issue more than 6,383,142 shares of the Series A-1 Preferred Stock to Novartis under the anti-dilution right. The Company assessed the Novartis anti-dilution right and determined that the right (i) meets the definition of a freestanding financial instrument that is not indexed to the Company’s own stock and (ii) meets the definition of a derivative and does not qualify for equity classification. The initial fair value of the anti-dilution right liability of $1.0 million was recorded as research and development expense in July 2019, as part of the initial consideration in the license agreement. The Company remeasured the liability associated with the anti-dilution right at each reporting date and at each issuance of Series A-1 Preferred Stock under the anti-dilution right. Changes in the fair value were recorded as other income and expense in the statement of operations until the anti-dilution right was satisfied in February 2021 upon the Company raising aggregate cumulative proceeds of $30.0 million in sales of equity securities. As part of the anti-dilution right, the Company issued a total of 5,970,000 shares of Series A-1 Preferred Stock to Novartis. No expense was recognized during the year ended December 31, 2022 or thereafter, as the anti-dilution liability was satisfied in February 2021.

Under the Novartis License Agreement, the Company is obligated to make aggregate milestone payments of up to $231.7 million related to the achievement of specified development, commercialization, and sales milestones. The Company records the milestone payments as research and development expenses when the milestones occur and consideration is paid or becomes payable. As of March 31, 2023, the Company has made two development milestone payments under the Novartis Agreement totaling $1.0 million, of which $0.4 million was achieved and paid in 2019, and $0.6 million was achieved and paid in 2020, which were recorded as research and development expense. No other milestones have occurred or have been paid under the Novartis License Agreement.

As part of the Novartis License Agreement, the Company also agreed to pay tiered royalties based on future net sales of all products licensed under the agreement, of which the royalty percentage ranged within the single digits.

Stockholder's Equity (Deficit)

3 Months Ended

Mar. 31, 2023

Equity [Abstract]

Stockholder's Equity (Deficit)

7. Stockholder's Equity (Deficit)

Common stock

As of December 31, 2022 and March 31, 2023, the Company’s Amended and Restated Certificate of Incorporation authorized the Company to issue 500,000,000 shares of common stock, with a par value of $0.0001. The holders of the common stock are entitled to one vote for each share of common stock held on all matters submitted to a vote of stockholders. There are not cumulative voting rights for the election of directors in the restated certificate of incorporation, which means that holders of a majority of the shares of the common stock will be able to elect all of the directors. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, or the Board, if any, subject to the preferential dividend rights of redeemable convertible preferred stock. Through March 31, 2023, no cash dividends had been declared or paid.

On September 19, 2022, the Company completed its IPO, at which time the Company issued 12,535,000 shares of common stock, including the exercise in full by the underwriters of their option to purchase up to 1,635,000 additional shares of common stock, at a public offering price of $17.00 per share. The Company received $198.2 million, net of underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were $2.3 million. Upon the closing of the IPO, all outstanding shares of redeemable convertible preferred stock converted into 21,967,316 shares of common stock. As of December 31, 2022 and March 31, 2023, there were 39,377,222 and 39,484,403 shares of common stock issued and outstanding, respectively.

The following shares of common stock were reserved for issuance as follows:


	December 31, 2022		March 31, 2023
Options to purchase common stock		3,644,500		5,024,356
Unvested restricted common stock		964,992		857,811
Remaining shares reserved for future issuance		3,801,282	1,885,604
Total		8,410,774		5,882,167

Undesignated preferred stock

As of March 31, 2023, the Company’s Amended and Restated Certificate of Incorporation authorized the Company to issue up to 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share. There were no undesignated preferred shares issued or outstanding as of March 31, 2023.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

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+ Details

Stock-Based Compensation

3 Months Ended

Mar. 31, 2023

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

8. Stock-Based Compensation

2019 Stock Incentive Plan

The Company's 2019 Stock Incentive Plan, or the 2019 Plan, provided for the Company to grant incentive stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock-based awards. The 2019 Plan was administered by the Board or, at the discretion of the Board, by a committee delegated by Board. The exercise prices, vesting and other restrictions were determined at the discretion of the Board, or its committee if so delegated. The Company’s Board valued the Company’s common stock, taking into consideration its most recently available valuation of common stock performed by third party valuation specialists as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant.

The total number of shares of common stock that could have been issued under the 2019 Plan was 5,317,559 shares, of which 474,951 shares remained available for grant on September 19, 2022, the date that the Company's 2022 Equity Incentive Plan, or the 2022 Plan, became effective. Upon the effectiveness of the 2022 Plan, the 474,951 remaining shares available under the 2019 Plan were transferred and became available for issuance under the 2022 Plan. Shares of common stock underlying outstanding awards under the 2019 Plan that are forfeited, cancelled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, reacquired by the Company prior to vesting, satisfied without the issuance of stock, expire or are otherwise terminated (other than by exercise) will be added to the shares of common stock available for issuance under the 2022 Plan.

2022 Plan

The 2022 Plan was approved by the Board and stockholders in August 2022. The 2022 Plan became effective on September 14, 2022 and replaced the Company's 2019 Plan on that date. The 2022 Plan authorizes the award of incentive stock options, or ISOs, non-qualified stock options, or NQSOs, Restricted Stock Awards, or RSAs, Stock Appreciation Rights, or SARs, Restricted Stock Units, or RSUs, performance awards and stock bonus awards. Pursuant to the 2022 Plan, ISOs may be granted only to employees.

The number of shares initially reserved for issuance under the 2022 Plan is 4,901,688 shares of common stock, which includes the 474,951 shares transferred from the 2019 Plan, and shall automatically increase on January 1 of each of 2023 through 2032 by the number of shares equal of the lesser of 5% of the aggregate number of shares of all classes of the common stock, plus the total number of shares of common stock issuable upon conversion of any preferred stock (if any) or exercise of any pre-funded warrants, as issued and outstanding as of the immediately preceding December 31, or a number as may be determined by the Board.

The 2022 Plan is administered by the Board or, at the discretion of the Board, by a committee of the Board. The exercise prices, vesting and other restrictions are determined at the discretion of the Board, or its committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant and the term of stock option may not be greater than ten years.

Shares that are expired terminated, surrendered or cancelled under the 2022 Plan without having been fully exercised will be available for future awards.

Stock Options

The assumptions that the Company used to determine the grant-date fair value of stock options awarded to employees, were as follows for the three months ended March 31, 2022 and 2023:


	Three Months Ended March 31,
	2022		2023
Expected term (in years)	6.06-6.53		5.21-6.96
Expected volatility	82.3-82.7%		85.7-87.1%
Risk-free interest rate	1.70-2.56%		3.55-4.21%
Expected dividend yield		—		—
Fair value of stock option	$6.51-6.73		$3.00-3.27

The following table summarizes the Company’s stock option activity since December 31, 2022:


	Number of Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2022		3,644,500		$	10.45		9.51	$	1,283
Granted		1,457,900			4.22
Exercised		—			—
Forfeited or cancelled		(78,044	)		4.18
Outstanding as of March 31, 2023		5,024,356			4.03		9.35		1,052
Options vested and exercisable as of March 31, 2023		606,727			3.37		8.72		606
Options unvested as of March 31, 2023		4,417,629			4.12		9.44		445

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock.

The weighted-average grant-date fair value per share of stock options granted during the three months ended March 31, 2023 was $3.14. As of March 31, 2023, there was $28.0 million of unrecognized stock-based compensation expense related to unvested stock options, to be recognized over a weighted-average period of 3.38 years.

The total fair value of options vested during the three months ended March 31, 2023 was $3.9 million.

Included within the total stock options outstanding are 95,461 stock options to purchase common stock which have performance-based vesting criteria and were granted to certain employees, officers and consultants of the Company on various dates during the years ended December 31, 2020 and 2021, collectively, the Performance Stock Options. Vesting of 37,133 of the Performance Stock Options was contingent on the closing of the Series A-2 Second Tranche, which occurred on February 24, 2021, and vesting of the remaining 97,938 Performance Stock Options was contingent on the closing of the Series A-3 Second Tranche, which occurred on November 15, 2021. The vesting commencement date of the Performance Stock Options was the date in which the performance condition is met, and vesting occurs based on the accelerated attribution method over four years from the vesting commencement date. The Company began to recognize expense associated with the Performance Stock Options on the date in which each respective performance criteria was met and recognized total stock-based compensation expense associated with the Performance Stock Options of less than $0.1 million for the three months ended March 31, 2023. No expense associated with the Performance Stock Options was recognized prior to the year ended December 31, 2022.

Repricing of Stock Options

On March 6, 2023, the Board approved the reduction in exercise price of certain options that had been granted under the 2019 Plan and the 2022 Plan, that have an exercise price greater than or equal to $8.61 per share, which were each repriced at an exercise price of $4.20 effective March 21, 2023. There were no changes in the vesting schedule or maturity term of the options.

Options representing 3,085,468 underlying shares were included in this repricing and the total incremental stock-based compensation expense associated with the modification of these options was $2.1 million. The incremental expense as a result of the repricing was recognized immediately for vested awards, and the incremental expense for the unvested awards will be recognized over the remaining requisite service period.

Restricted Common Stock Awards

The Company has granted restricted common stock awards with service and performance and service based vesting conditions to employees of the Company. Unvested shares of restricted common stock may not be sold or transferred by the holder, except for transfers for estate planning purposes in which the transferee agrees to remain bound by all restrictions set forth in the original common stock purchase agreement. These restrictions lapse over the vesting term of each award, which is typically four years. The purchase price of each share of restricted common stock was $0.0001 per share.

On August 9, 2021, the Company’s chief executive office, or CEO, purchased 1,218,836 shares of common stock at a purchase price of $1.44 per share, under the terms of a restricted common stock award granted under the 2019 Plan. These shares were purchased in exchange for a promissory note, or the Promissory Note, of $1.8 million. The shares granted include both service and performance-based vesting criteria and accrued at an interest rate of 0.76% per annum, compounded annually and were accounted for as restricted stock.

On August 22, 2022, the Company forgave the entire promissory note, including principal and accrued and unpaid interest. As a result this is considered a modification to the original awards, and the Company recognized the grant date fair value plus any incremental fair value due to the modification. The incremental cost was measured as the difference between the fair value of the award at modification date and the fair value of the original award immediately prior to modification. As a result of accounting for the modification, the Company recorded an incremental stock-based compensation charge of $1.0 million, which will be recognized over the remaining requisite service period of award from the date of the modification.

The CEO was paid a one-time special bonus of $1.9 million to offset the CEO’s tax liability as a result of the forgiveness of the promissory note, or the Tax Payment, which is subject to a three-year vesting schedule with six-month cliffs. The Company is allowed to claw-back the unvested portion of the Tax Payment in the event that the CEO’s employment is terminated before the end of the three-year vesting period, provided that the CEO’s employment is terminated by the Company other than for cause, or if the CEO resigns for a good reason (a) within 12 months following a change of control, or (b) within 3 months preceding a change in control but as to only if the separation occurs after a potential change in control. In the event the CEO’s employment is terminated, the unvested portion of the Tax Payment will accelerate and will not be subject to the claw back provision. The clawback provision will be accounted for if and when the CEO leaves under the relevant circumstances and the payment amount will be capitalized and recognized over the related service period as G&A employee salary expense.

A summary of the activity of the restricted common stock since December 31, 2022:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Unvested at December 31, 2022		964,992		$	1.34
Granted		—			—
Vested		(107,181	)		1.35
Cancelled or forfeited		—			—
Unvested at March 31, 2023		857,811		$	1.35

The weighted-average grant-date fair value per share of restricted common stock awards granted during the three months ended March 31, 2023 was zero as no shares were granted in the period. The aggregate fair value of restricted stock awards that vested during the three months ended March 31, 2023 was $0.1 million. Stock-based compensation expense recognized for the restricted stock granted was $0.1 million for the three months ended March 31, 2023. As of March 31, 2023, there was unrecognized expense of $1.0 million related to the restricted stock, which is expected to be recognized over a weighted-average period of 2.22 years.

Stock-Based Compensation Expense

Stock-based compensation expense included in the Company’s condensed consolidated statements of operations was as follows (in thousands):


	Three Months Ended March 31,
	2022		2023
Research and development	$	147	$	1,018
General and administrative		303		1,664
Total stock-based compensation expense	$	450	$	2,682

Income Taxes

3 Months Ended

Mar. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

9. Income Taxes

During the three months ended March 31, 2022 and 2023, the Company recorded no income tax provision or benefit.

The Company has evaluated the positive and negative evidence bearing upon its ability to realize its deferred tax assets, which primarily consist of net operating loss carryforwards. The Company has considered its history of cumulative net losses, estimated future taxable income and prudent and feasible tax planning strategies and has concluded that it is more likely than not that the Company will not realize the benefits of its deferred tax assets. As a result, as of March 31, 2023, the Company has maintained a full valuation allowance against its remaining net deferred tax assets.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Net Loss Per Share

3 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

10. Net Loss Per Share

The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2022		2023
Numerator:
Net loss	$	7,784	$	9,085
Net loss attributable to common stockholders, basic and diluted	$	7,784	$	9,085
Denominator:
Weighted-average number of common shares used in net loss per share, basic and diluted		9,643,963		22,792,781
Net loss per share of common stock, basic and diluted	$	0.81	$	0.40

The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders during the three months ended March 31, 2022 and 2023 because including them would have had an anti-dilutive effect:


	Three Months Ended March 31,
	2022		2023
Redeemable convertible preferred stock		21,967,316		—
Options to purchase common stock		3,644,500		5,024,356
Unvested restricted stock		964,992		857,811
Total		26,576,808		5,882,167

Leases

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Leases

11. Leases

Operating Leases

In October 2022, the Company entered into an office space lease approximating 10,356 of rentable square feet, located at 130 Prospect Street in Cambridge, Massachusetts. The lease commenced on December 1, 2022 when the Company took occupancy of the space, and has an initial lease term of 63 months, expiring on February 29, 2028 with no renewal options.

Also in October 2022, the Company entered into an office space lease approximating 4,703 of rentable square feet located at 1700 Montgomery Street in San Francisco, California. The lease commenced on December 20, 2022 when the Company took occupancy of the space, and has an initial lease term of 63 months, expiring on February 20, 2028 with no renewal options.

The Company also leased various office suites on a month-to month basis from Atlas Venture Life Science Advisors, or Atlas, and other third parties during the year ended December 31, 2022. During the three months ended March 31, 2022, the Company incurred $39.1 thousand of short-term lease expense associated with the month-to-month lease. During the three months ended March 31, 2023, the Company did not incur any short term lease costs. As the Company elected to not recognize leases with a lease term of 12 months or less on the balance sheet, no operating lease right of use assets and liabilities were recognized.

During the three months ended March 31, 2022 and 2023 the components of operating lease cost were as follows, and are reflected in general and administrative expenses and research and development expenses, as determined by the underlying activities:


	March 31, 2022		March 31, 2023
Lease Cost:
Operating lease cost	$	—	$	274
Variable operating lease cost		—		—
Short-term operating lease cost		39		—
Total operating lease cost	$	39	$	274

The following table summarizes information related to the measurement of the Company's operating leases for the years ended December 31, 2022 and three months ended March 31, 2023:


	December 31, 2022			March 31, 2023
Weighted-average remaining lease term		5.20			4.90
Weighted-average discount rate		10.5	%		10.5	%

There was no cash paid for amounts included in the measurement of operating lease liabilities for each of the three months ended March 31, 2022 and 2023.

Maturities of operating lease liabilities at March 31, 2023 are as follows (in thousands):


2023 (remaining)	$	815
2024		1,116
2025		1,145
2026		1,176
2027		1,207
Thereafter		238
Total lease payments		5,697
Less: interest		(1,254	)
Total lease liability	$	4,443

Commitments and Contingencies

3 Months Ended

Mar. 31, 2023

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

12. Commitments and Contingencies

Legal Proceedings

From time to time, in the ordinary course of business, the Company is subject to litigation and regulatory examinations as well as information gathering requests, inquiries and investigations. As of December 31, 2022 and March 31, 2023, there were no litigation matters which would have a material impact on the Company’s financial results.

Related Party Transactions

3 Months Ended

Mar. 31, 2023

Related Party Transactions

13. Related Party Transactions

Entities Affiliated with Atlas Venture Fund XI, L.P.

Entities affiliated with Atlas Venture Fund XI, L.P. are a significant beneficial owner of the Company, holding more than 5% of the total outstanding stock of the Company, as of December 31, 2022 and March 31, 2023. The Company leased various office space from Atlas for use in its daily operations through September 2022.

During the three months ended March 31, 2022, the Company made payments of $39.1 thousand associated with the lease agreements with Atlas, which was recorded within the general and administrative expense.

Novartis

Novartis is a significant beneficial owner of the Company, holding more than 5% of the total outstanding stock of the Company, as of December 31, 2022 and March 31, 2023. The Company has an in-license agreement with Novartis, which required the Company to make an upfront payment and issue shares of Series A-1 Preferred Stock to Novartis, and further includes future milestone payments upon the occurrence of certain events and royalty payments upon future sales. Refer to Note 6.

CEO Promissory Note

On August 9, 2021, the Company entered into the Promissory Note with the CEO for an amount of $1.8 million, which was used to allow the CEO to purchase 1,218,836 shares of common stock granted in the form of a restricted stock award under the 2019 Plan. The Promissory Note had a stated interest rate of 0.76%, which was compounded annually. The entire Promissory Note, including principal and accrued and unpaid interest, was forgiven on August 22, 2022. The Company has paid the CEO a one-time special bonus of $1.9 million, which was paid to offset the CEO's tax liability as a result of the forgiveness of the Promissory Note. This is subject to a three-year vesting schedule with six-month cliffs, as well as continued employment with the company on the relevant vesting dates. Refer to Note 8.

Employee Benefit Plans

3 Months Ended

Mar. 31, 2023

Compensation And Retirement Disclosure [Abstract]

Employee Benefit Plans

14. Employee Benefit Plans

Effective January 1, 2019, the Company adopted a 401(k) Plan for its employees, which is designed to be qualified under Section 401(k) of the Internal Revenue Code. Eligible employees are permitted to contribute to the 401(k) Plan within statutory and 401(k) Plan limits. Since inception of the plan and through the three months ended March 31, 2023 the Company has not made any contributions to the 401(k) Plan.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Subsequent Events

3 Months Ended

Mar. 31, 2023

Subsequent Events [Abstract]

Subsequent Events

15. Subsequent Events

The Company has completed an evaluation of all subsequent events after the balance sheet date of March 31, 2023 through May 11, 2023, the date these financial statements were issued, to ensure that these financial statements include appropriate disclosure of events both recognized in the financial statements as of March 31, 2023 and events which occurred subsequently but were not recognized in the accompanying condensed consolidated financial statements. No subsequent events have occurred that require disclosure.

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2023
Accounting Policies [Abstract]
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, for interim financial reporting and as required by Regulation S-X, Rule 10-01. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated annual financial statements for the years ended December 31, 2021 and 2022 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s condensed consolidated balance sheet as of March 31, 2023, the condensed consolidated statements of operations for the three months ended March 31, 2022 and 2023, the condensed consolidated statement of stockholders' equity (deficit) as of March 31, 2023 and condensed consolidated statements of cash flows for the three months ended March 31, 2022 and 2023. The financial data and other information disclosed in these notes related to the three months ended March 31, 2022 and 2023 are unaudited. The results for the three months ended March 31, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted Management evaluated recently issued accounting pronouncements and does not believe that any of these pronouncements will have a significant impact on the condensed consolidated financial statements and related disclosures.

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Financial Assets Measured at Fair Value

The following tables present information about the Company’s financial assets measured at fair value on a recurring basis (in thousands):


			December 31, 2022
Description	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Observable Inputs (Level 3)
Money market funds	$	286,580	$	286,580	$	—	$	—
Total financial assets	$	286,580	$	286,580	$	—	$	—


			March 31, 2023
Description	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Observable Inputs (Level 3)
Money market funds	$	280,812	$	280,812	$	—	$	—
Total financial assets	$	280,812	$	280,812	$	—	$	—

Property, Plant and Equipment (Tables)

3 Months Ended

Mar. 31, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment

Property, plant and equipment consisted of the following (in thousands):


	December 31, 2022			March 31, 2023
Construction in progress	$	16		$	—
Leasehold Improvement		—			12
Computer equipment		20			51
Property, plant and equipment, gross		36			63
Less: Accumulated depreciation		(1	)		(3	)
Property, plant and equipment, net	$	35		$	60

Accrued Expenses and Other Current Liabilities (Tables)

3 Months Ended

Mar. 31, 2023

Payables And Accruals [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2022		March 31, 2023
Accrued research and development expenses	$	1,444	$	705
Professional fees		339		124
Employee compensation and related benefits		1,165		754
Other		233		26
Total accrued expenses and other current liabilities	$	3,181	$	1,609

Stockholder's Equity (Deficit) (Tables)

3 Months Ended

Mar. 31, 2023

Equity [Abstract]

Schedule of Common Stock Reserved for Issuance

The following shares of common stock were reserved for issuance as follows:


	December 31, 2022		March 31, 2023
Options to purchase common stock		3,644,500		5,024,356
Unvested restricted common stock		964,992		857,811
Remaining shares reserved for future issuance		3,801,282	1,885,604
Total		8,410,774		5,882,167

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2023

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Options Valuation Assumptions

The assumptions that the Company used to determine the grant-date fair value of stock options awarded to employees, were as follows for the three months ended March 31, 2022 and 2023:


	Three Months Ended March 31,
	2022		2023
Expected term (in years)	6.06-6.53		5.21-6.96
Expected volatility	82.3-82.7%		85.7-87.1%
Risk-free interest rate	1.70-2.56%		3.55-4.21%
Expected dividend yield		—		—
Fair value of stock option	$6.51-6.73		$3.00-3.27

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity since December 31, 2022:


	Number of Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2022		3,644,500		$	10.45		9.51	$	1,283
Granted		1,457,900			4.22
Exercised		—			—
Forfeited or cancelled		(78,044	)		4.18
Outstanding as of March 31, 2023		5,024,356			4.03		9.35		1,052
Options vested and exercisable as of March 31, 2023		606,727			3.37		8.72		606
Options unvested as of March 31, 2023		4,417,629			4.12		9.44		445

Summary of Restricted Common Stock Activity

A summary of the activity of the restricted common stock since December 31, 2022:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Unvested at December 31, 2022		964,992		$	1.34
Granted		—			—
Vested		(107,181	)		1.35
Cancelled or forfeited		—			—
Unvested at March 31, 2023		857,811		$	1.35

Summary of Stock-Based Compensation Expense

Stock-based compensation expense included in the Company’s condensed consolidated statements of operations was as follows (in thousands):


	Three Months Ended March 31,
	2022		2023
Research and development	$	147	$	1,018
General and administrative		303		1,664
Total stock-based compensation expense	$	450	$	2,682

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2022		2023
Numerator:
Net loss	$	7,784	$	9,085
Net loss attributable to common stockholders, basic and diluted	$	7,784	$	9,085
Denominator:
Weighted-average number of common shares used in net loss per share, basic and diluted		9,643,963		22,792,781
Net loss per share of common stock, basic and diluted	$	0.81	$	0.40

Schedule of Computation of Diluted Net Loss Per Share Attributable to Common Stockholders Anti-dilutive Effect


	Three Months Ended March 31,
	2022		2023
Redeemable convertible preferred stock		21,967,316		—
Options to purchase common stock		3,644,500		5,024,356
Unvested restricted stock		964,992		857,811
Total		26,576,808		5,882,167

Leases (Tables)

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Components of Operating Lease Cost


	March 31, 2022		March 31, 2023
Lease Cost:
Operating lease cost	$	—	$	274
Variable operating lease cost		—		—
Short-term operating lease cost		39		—
Total operating lease cost	$	39	$	274

Summary of Information Related to Measurement of Operating Leases

The following table summarizes information related to the measurement of the Company's operating leases for the years ended December 31, 2022 and three months ended March 31, 2023:


	December 31, 2022			March 31, 2023
Weighted-average remaining lease term		5.20			4.90
Weighted-average discount rate		10.5	%		10.5	%

Maturities of Operating Lease Liabilities

Maturities of operating lease liabilities at March 31, 2023 are as follows (in thousands):


2023 (remaining)	$	815
2024		1,116
2025		1,145
2026		1,176
2027		1,207
Thereafter		238
Total lease payments		5,697
Less: interest		(1,254	)
Total lease liability	$	4,443

Nature of the Business - Additional Information (Detail) $ / shares in Units, $ in Thousands			3 Months Ended
	Sep. 19, 2022 USD ($) $ / shares shares	Sep. 07, 2022	Mar. 31, 2023 USD ($) Office $ / shares shares	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) $ / shares shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of offices \| Office			2
Number of shares authorized for issuance			500,000,000		500,000,000
Par value of common stock \| $ / shares			$ 0.0001		$ 0.0001
Preferred stock, Par Value \| $ / shares			$ 0.0001
Description of reverse stock split			Company effected a 1-for-2.259 reverse stock split of the Company’s outstanding common stock
Reverse stock spilt conversion ratio		0.44267375
Net loss \| $			$ (9,085)	$ (7,784)
Accumulated deficit \| $			92,481		$ 83,396
Cash and cash equivalents \| $			$ 282,202		$ 288,877
Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Undesignated preferred stock, authorized			10,000,000
IPO
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial public offering, Shares	12,535,000
Public offering price \| $ / shares	$ 17.00
Proceeds from initial public offering \| $	$ 198,200
Offering costs payable \| $	$ 2,300
Conversion of convertible preferred stock into common stock	21,967,316
Number of shares authorized for issuance	500,000,000
Par value of common stock \| $ / shares	$ 0.0001
Undesignated preferred stock, authorized	10,000,000
Preferred stock, Par Value \| $ / shares	$ 0.0001
Net loss \| $			$ (9,100)	$ (7,800)
Underwrites Option \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial public offering, Shares	1,635,000

Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 280,812	$ 286,580
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	280,812	286,580
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Significant Other Observable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	280,812	286,580
Money Market Funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	280,812	286,580
Money Market Funds \| Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Money Market Funds \| Significant Other Observable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 0	$ 0

Fair Value Measurements - Additional Information (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Line Items]
Transfers or reclassifications between fair value measurement levels of assets	$ 0	$ 0
Transfers or reclassifications between fair value measurement levels of liabilities	0	0
Cash and Cash Equivalents
Fair Value Disclosures [Line Items]
Fair value measurement of financial liabilities	$ 0	$ 0

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 63	$ 36
Less: Accumulated depreciation	(3)	(1)
Property, plant and equipment, net	60	35
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	0	16
Leasehold Improvement
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	12	0
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 51	$ 20

Property, Plant and Equipment - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 3,000	$ 0
General and Administrative Expenses
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 3,000.0		$ 1,000.0

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 705	$ 1,444
Professional fees	124	339
Employee compensation and related benefits	754	1,165
Other	26	233
Total accrued expenses and other current liabilities	$ 1,609	$ 3,181

Novartis License Agreement - Additional Information (Details)			3 Months Ended	12 Months Ended
	Feb. 28, 2021 USD ($)	Jun. 28, 2019 USD ($) License shares	Mar. 31, 2023 USD ($) License shares	Dec. 31, 2022 USD ($)	Feb. 24, 2021 shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
License Agreement [Line Items]
Preferred stock, shares issued \| shares			0
Novartis License Agreement \| Novartis
License Agreement [Line Items]
Number of licensed compounds \| License		2
Number of licensed Product \| License		1
Upfront cash payment		$ 400,000
Total initial consideration transferred		3,400,000
Changes in fair value of anti dilution right liability				$ 0
Aggregate milestone payments		231,700,000
Number of development milestone payments \| License			2
Development milestone payments			$ 1,000,000.0
Milestone payments achieved and paid						$ 600,000	$ 400,000
Novartis License Agreement \| Novartis \| Research and Development Expense
License Agreement [Line Items]
Initial fair value of anti-dilution right liability		$ 1,000,000.0
Novartis License Agreement \| Series A-1 Preferred Stock \| Maximum
License Agreement [Line Items]
Preferred stock, shares issued \| shares		6,383,142
Novartis License Agreement \| Series A-1 Preferred Stock \| Novartis
License Agreement [Line Items]
Preferred stock, shares issued \| shares		3,449,808
Fair value of stock		$ 3,000,000.0
Ownership interest		15.00%
Licensing milestone in sales of equity securities	$ 30,000,000.0	$ 30,000,000.0
Novartis License Agreement \| Series A-1 Preferred Stock \| Novartis \| Minimum
License Agreement [Line Items]
Licensing milestone in sales of equity securities		$ 30,000,000.0
Novartis License Agreement \| Series A-1 Preferred Stock \| Novartis \| Maximum
License Agreement [Line Items]
Preferred stock, shares issued \| shares					5,970,000

Stockholder's Equity (Deficit) - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		51 Months Ended
	Sep. 19, 2022	Mar. 31, 2023	Dec. 31, 2022
Subsidiary, Sale of Stock [Line Items]
Common Stock, Shares Authorized		500,000,000	500,000,000
Common Stock, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
Common stock voting rights		one vote for each share
Common stock, cash dividends declared		$ 0
Common Stock Shares Issued		39,484,403	39,377,222
Common Stock Shares Outstanding		39,484,403	39,377,222
Preferred stock, Par Value		$ 0.0001
Undesignated preferred shares issued		0
Preferred shares outstanding		0
Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Undesignated preferred stock, authorized		10,000,000
IPO
Subsidiary, Sale of Stock [Line Items]
Common Stock, Shares Authorized	500,000,000
Initial public offering, Shares	12,535,000
Common Stock, Par or Stated Value Per Share	$ 0.0001
Public offering price	$ 17.00
Proceeds from issuing shares	$ 198.2
Offering costs	$ 2.3
Conversion of convertible preferred stock into common stock	21,967,316
Undesignated preferred stock, authorized	10,000,000
Preferred stock, Par Value	$ 0.0001
Over allotment \| Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Initial public offering, Shares	1,635,000

Stockholder's Equity (Deficit) - Schedule of Common Stock Reserved for Issuance (Details) - shares	Mar. 31, 2023	Dec. 31, 2022
Options to purchase common stock	5,024,356	3,644,500
Unvested restricted common stock	857,811	964,992
Remaining shares reserved for future issuance	1,885,604	3,801,282
Total	5,882,167	8,410,774

Stock-Based Compensation - Additional Information (Details) - USD ($)						3 Months Ended		12 Months Ended
	Mar. 21, 2023	Aug. 22, 2022	Nov. 15, 2021	Aug. 09, 2021	Feb. 24, 2021	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Mar. 06, 2023	Sep. 19, 2022	Sep. 14, 2022	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance						5,882,167		8,410,774
Stock-based compensation expense						$ 2,682,000	$ 450,000
CEO Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period						3 years
Special bonus paid		$ 1,900,000
Award vesting description						subject to a three-year vesting schedule with six-month cliffs
Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service period						3 months
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value per share of stock options						$ 3.14
Unrecognized stock-based compensation expense related to unvested stock options						$ 28,000,000.0
Unrecognized stock based compensation expense period of recognition						3 years 4 months 17 days
Fair value of options vested						$ 3,900,000
Outstanding stock options to purchase common stock						5,024,356		3,644,500
Repriced of exercise price	$ 4.20
Number of options included in repricing	3,085,468
Total incremental stock-based compensation expense associated with modification of options	$ 2,100,000
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting over period						4 years
Stock-based compensation expense								$ 0
Performance Stock Options \| Performance Based Vesting
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding stock options to purchase common stock												95,461	95,461
Performance Stock Options \| Series A-2 Second Tranche
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting of performance stock					37,133
Performance Stock Options \| Series A-3 Second Tranche
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting of remaining performance stock			97,938
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period						4 years
Unrecognized stock based compensation expense period of recognition						2 years 2 months 19 days
Stock-based compensation expense						$ 100,000
Share price						$ 0.0001
Remaining unrecognized expense		1,000,000.0
Weighted average grant date fair value						$ 0
Granted in period						0
Aggregate fair value of restricted stock awards vested						$ 100,000
Unrecognized expense						$ 1,000,000.0
Restricted Stock \| Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exchangeable value of shares purchased				$ 1,800,000
Restricted Stock \| Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share price				$ 1.44
Number of shares purchased				1,218,836
Special bonus paid		$ 1,900,000
Contingency period						12 months
Restricted Stock \| Chief Executive Officer [Member] \| Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accrued Interest Rate				0.76%
2019 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock issuable under plan										5,317,559
Conversion of outstanding shares of preferred stock										474,951	474,951
Number of shares transferred						474,951
2022 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance						4,901,688
Maximum \| Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share price						$ 3.27	$ 6.73
Maximum \| Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense						$ 100,000
Maximum \| 2022 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of annual increase in number of shares to classes of common stock under plan						5.00%
Exercise price per share of stock options as percentage of fair market value of common stock						100.00%
Stock option expiration period						10 years
Minimum \| Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price									$ 8.61
Share price						$ 3.00	$ 6.51

Stock-Based Compensation - Summary of Stock Options Valuation Assumptions (Details) - Stock Options - $ / shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	3.55%	1.70%
Risk-free interest rate	4.21%	2.56%
Expected dividend yield	0.00%	0.00%
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 11 months 15 days	6 years 6 months 10 days
Expected volatility	87.10%	82.70%
Fair value of stock option	$ 3.27	$ 6.73
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 2 months 15 days	6 years 21 days
Expected volatility	85.70%	82.30%
Fair value of stock option	$ 3.00	$ 6.51

Stock-Based Compensation - Summary of Stock Option Activity (Details) - Stock Options - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance	3,644,500
Shares, Granted	1,457,900
Exercised	0
Forfeited or cancelled	(78,044)
Ending balance	5,024,356	3,644,500
Options vested and exercisable as of March 31, 2023	606,727
Options unvested as of March 31, 2023	4,417,629
Beginning balance	$ 10.45
Granted	4.22
Exercised	0
Forfeited or cancelled	4.18
Ending balance	4.03	$ 10.45
Options vested and exercisable as of March 31, 2023	3.37
Options unvested as of March 31, 2023	$ 4.12
Weighted-Average Remaining Contractual Term (in years)	9 years 4 months 6 days	9 years 6 months 3 days
Options vested and exercisable as of March 31, 2023	8 years 8 months 19 days
Options unvested as of March 31, 2023	9 years 5 months 8 days
Aggregate Intrinsic Value	$ 1,052	$ 1,283
Options vested and exercisable as of March 31, 2023	606
Options unvested as of March 31, 2023	$ 445

Stock-Based Compensation - Summary of Restricted Common Stock Activity (Details) - Restricted Stock	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance \| shares	964,992
Granted \| shares	0
Vested \| shares	(107,181)
Cancelled or forfeited \| shares	0
Ending balance \| shares	857,811
Beginning balance \| $ / shares	$ 1.34
Granted \| $ / shares	0
Vested \| $ / shares	1.35
Cancelled or forfeited \| $ / shares	0
Ending balance \| $ / shares	$ 1.35

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 2,682	$ 450
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,018	147
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,664	$ 303

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income tax provision or benefit	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Net loss	$ 9,085	$ 7,784
Net loss attributable to common stockholders, basic	9,085	7,784
Net loss attributable to common stockholders, diluted	$ 9,085	$ 7,784
Weighted-average number of common shares used in net loss per share, basic	22,792,781	9,643,963
Weighted-average number of common shares used in net loss per share, diluted	22,792,781	9,643,963
Net loss per share of common stock, basic	$ 0.40	$ 0.81
Net loss per share of common stock, diluted	$ 0.40	$ 0.81

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.

+ References + Details

Net Loss Per Share - Schedule of Computation of Diluted Net Loss Per Share Attributable to Common Stockholders Anti-dilutive Effect (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	5,882,167	26,576,808
Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	0	21,967,316
Options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	5,024,356	3,644,500
Unvested Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti diluted effect of diluted net loss per share	857,811	964,992

Leases - Additional Information (Details)	1 Months Ended	3 Months Ended
Leases - Additional Information (Details)	Oct. 31, 2022 USD ($) ft²	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Leases [Line Items]
Operating lease right of use assets	$ 0
Operating lease liabilities	$ 0	$ 668,000		$ 385,000
Short-term lease expense		0	$ 39,100
Cash paid for amounts included in the measurement of operating lease liabilities		$ 0	$ 0
130 Prospect Street in Cambridge, Massachusetts
Leases [Line Items]
Area of land \| ft²	10,356
Lease commencement date	Dec. 01, 2022
Initial lease term	63 months
Lease expiring date	Feb. 29, 2028
1700 Montgomery Street in San Francisco, California
Leases [Line Items]
Area of land \| ft²	4,703
Lease commencement date	Dec. 20, 2022
Initial lease term	63 months
Lease expiring date	Feb. 20, 2028

Leases - Components of Operating Lease Cost (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 274,000	$ 0
Variable operating lease cost	0	0
Short-term operating lease cost	0	39,100
Total operating lease cost	$ 274,000	$ 39,000

Leases - Summary of Information Related to Measurement of Operating Leases (Details)	Mar. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Weighted-average remaining lease term	4 years 10 months 24 days	5 years 2 months 12 days
Weighted-average discount rate	10.50%	10.50%

Leases - Maturities of Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Lessee, Operating Lease, Liability, to be Paid [Abstract]
2023 (remaining)	$ 815
2024	1,116
2025	1,145
2026	1,176
2027	1,207
Thereafter	238
Total lease payments	5,697
Less: interest	(1,254)
Total lease liability	$ 4,443

Related Party Transactions - Additional Information (Details) - USD ($)			3 Months Ended	12 Months Ended
	Aug. 22, 2022	Aug. 09, 2021	Mar. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Common stock issued (in shares)			39,484,403	39,377,222
Atlas Venture Fund XI, L.P \| General and Administrative
Related Party Transaction [Line Items]
Related party transaction payment			$ 39,100
Atlas Venture Fund XI, L.P \| Minimum
Related Party Transaction [Line Items]
Outstanding stock percentage			5.00%	5.00%
Novartis \| Minimum
Related Party Transaction [Line Items]
Outstanding stock percentage			5.00%	5.00%
CEO Promissory Note
Related Party Transaction [Line Items]
Promissory note agreement amount		$ 1,800,000
Common stock issued (in shares)		1,218,836
Interest rate of promissory note		0.76%
Special bonus paid	$ 1,900,000
Vesting period			3 years
Award vesting description			subject to a three-year vesting schedule with six-month cliffs