0001741830-23-000069 | 10-Q | XBRL Viewer

Print Document View Excel Document

Subsequent Event (Details) - Subsequent Event $ in Millions	Oct. 30, 2023 USD ($)
Subsequent Event [Line Items]
Reduction of workforce (as a percent)	19.00%
Employee Severance
Subsequent Event [Line Items]
Expected cost	$ 1.8
Employee COBRA Insurance
Subsequent Event [Line Items]
Expected cost	$ 0.3

Significant Accounting Policies, Estimates and Judgments (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of assets and liabilities at the date of the condensed financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed financial statements include, but are not limited to, revenue, the accrual of research and development expenses, the fair value of investments, the fair value of the Company’s long-lived assets, income tax uncertainties, the valuation of equity instruments and the incremental borrowing rate for determining the operating lease assets and liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with the provisions of Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”). The Company recognizes revenue when the Company’s customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods and services. To determine revenue recognition for arrangements within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when or as the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. The Company evaluates the promised goods or services in these agreements to determine which ones represent distinct performance obligations. These agreements may include the following types of promised goods or services: (i) grants of licenses and related transfer of know-how, (ii) performance of research and development services, and (iii) participation on joint research and/or development committees. They also may include options to obtain further research and development services and licenses to the Company’s intellectual property. The payment terms of these agreements may include nonrefundable upfront fees, payments for electing the contractual options, payments based upon the achievement of certain milestones, and royalty payments based on product sales derived from the collaboration. The Company exercises judgment in assessing those promised goods and services that are distinct and thus representative of performance obligations. To the extent the Company identifies multiple performance obligations in a contract, the Company must develop assumptions that require judgment to determine the estimated standalone selling price for each performance obligation in order to allocate the transaction price among the identified performance obligations. The transaction is allocated on a relative standalone selling price basis. Prior to recognizing revenue, the Company makes estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. These estimates are reassessed each reporting period as required. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligations when or as the performance obligations are satisfied. For performance obligations satisfied over time, the Company estimates the efforts needed to complete the performance obligations and recognizes revenue by measuring the progress towards complete satisfaction of the performance obligations using an input measure. The estimated period of performance and level of effort, including the value of the Company researchers’ time and third-party costs, are reviewed quarterly and adjusted, as needed, to reflect the Company’s current expectations. The measurement of progress is then used to calculate revenue, including any revenue adjustments as a result of the change in estimate. For arrangements that include sales-based royalties, including commercial milestone payments based on pre-specified level of sales, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligations to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). Achievement of these royalties and commercial milestones may solely depend upon the performance of the licensee. Funds received in advance are recorded as deferred revenue and are recognized as the related performance obligations are satisfied. There are no performance, cancellation, termination, or refund provisions in any of the arrangements that contain material financial consequences to the Company.
Recent Accounting Pronouncements	Recent Accounting Pronouncements The Company continues to monitor new accounting pronouncements issued by the Financial Accounting Standards Board and does not believe any accounting pronouncements issued, and not yet adopted, through the date of this report will have a material impact on the Company's consolidated financial statements.

- Definition

Disclosure of accounting policy for revenue from contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-19

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-18

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-18

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (e)
-SubTopic 10
-Topic 235
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483426/235-10-50-4

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org//606/tableOfContent

+ Details

Leases - Schedule of Maturities on Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Leases [Abstract]
Remaining three months of 2023	$ 1,440
2024	5,749
2025	5,921
2026	5,405
2027 and thereafter	21,298
Total undiscounted lease payments	39,813
Less: Present value adjustment	(10,271)
Present value of operating lease liabilities	$ 29,542	$ 31,091

Stock-Based Compensation

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

2020 Equity Incentive Plan

In October 2020, the Company adopted its 2020 Equity Incentive Plan (the 2020 Plan) which replaced the 2017 Equity Incentive Plan (Prior Plan) upon completion of the IPO. The 2020 Plan provides for the grant of incentive stock options or nonqualified stock options, stock appreciation rights, restricted stock awards (“RSA”), restricted stock units (“RSU”), performance awards and other forms of awards to employees, directors, and consultants of the Company. The number of shares of common stock reserved for issuance under the 2020 Plan will automatically increase each year for a period of ten years, beginning in 2021 and continuing through 2030, in an amount equal to (1) 5.0% of the total number of shares of the Company’s common stock outstanding on December 31 of the immediately preceding year, or (2) a lesser number of shares determined by the Board of Directors no later than December 31 of the immediately preceding year. As of September 30, 2023, the maximum number of shares of common stock that may be issued was 20,417,192 shares.

The Company recognizes the impact of forfeitures on stock-based compensation expense as forfeitures occur. The Company applies the straight-line method of expense recognition to all awards with only service-based vesting conditions. Options shall not have an exercise price less than 100% of the fair market value of the Company’s common stock on the grant date. Vesting periods are determined at the discretion of the Board of Directors. Stock options typically vest over four years. The maximum contractual term is 10 years.

As of September 30, 2023, there were 4,260,124 shares reserved by the Company under the 2020 Plan for the future issuance of equity awards.

Stock Options

Stock option activity under the 2020 Plan as of September 30, 2023 is summarized as follows:


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
				(in years)	(in thousands)
Balance, December 31, 2022	7,454,665	$	11.83	7.69	$	54
Granted	3,200,631	1.99
Forfeited	(1,471,660)	10.94
Exercised	(242,379)	3.21
Balance, September 30, 2023	8,941,257	$	8.69	8.00	$	17

The aggregate intrinsic values of options outstanding was calculated as the difference between the exercise price of the options and the closing price of the Company’s common stock on the Nasdaq Global Select Market on September 30, 2023. There was no future tax benefit related to options exercised, as the Company had accumulated net operating losses as of September 30, 2023 and December 31, 2022.

The weighted-average grant-date fair value per share of stock options granted, using the Black–Scholes option pricing model, was $1.41 during the nine months ended September 30, 2023.

As of September 30, 2023 and December 31, 2022, there was $20.2 million and $35.4 million of unrecognized stock-based compensation related to stock options, respectively, which is expected to be recognized over a weighted-average period of 1.89 years and 2.25 years, respectively.

Restricted Stock

Restricted stock awards and restricted stock units as of September 30, 2023 are summarized as follows:


	Number of Restricted Stock	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Vesting Life	Aggregate Intrinsic Value
				(in years)	(in thousands)
Unvested, December 31, 2022	2,297,745	$	9.18	1.58	$	3,722
Granted	1,611,211	1.99
Vested and converted to shares	(723,876)	8.21
Forfeited	(652,996)	5.25
Unvested, September 30, 2023	2,532,084	$	5.90	1.08	$	3,292

As of September 30, 2023, there was $6.6 million of unrecognized stock-based compensation related to RSUs, which is expected to be recognized over a weighted average remaining vesting life.

As of September 30, 2023, there was $0.1 million of unrecognized stock-based compensation related to RSAs, which is expected to be recognized over a weighted average remaining vesting life.

2020 Employee Stock Purchase Plan

In October 2020, the Company adopted its 2020 Employee Stock Purchase Plan (ESPP), which initially reserved 688,000 shares of the Company’s common stock for employee purchase under terms and provisions established by the Board of Directors. The number of shares of our common stock reserved for issuance under the ESPP automatically increased in 2021 and continues to increase through 2030, by the lesser of (i) 1.0% of the total number of shares of common stock outstanding on December 31 of the immediately preceding year, and (ii) 1,376,000 shares, except before the date of any increase, the Board of Directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii). The Company did not issue any shares of common stock during both the three months ended September 30, 2023 and 2022. The Company issued 247,048 shares and 12,539 shares of common stock during the nine months ended September 30, 2023 and 2022, respectively.

Stock-Based Compensation Summary

Total stock-based compensation expense related to stock options, restricted stock units, restricted stock awards and the employee stock purchase plan for the three and nine months ended September 30, 2023 and 2022 is as follows (in thousands):


	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Research and development expenses	$	3,237	$	3,500	$	9,472	$	11,355
General and administrative expenses	3,059		3,961		10,337		12,101
Total stock-based compensation expense	$	6,296	$	7,461	$	19,809	$	23,456

Early Exercised Options

The Company allows certain of its employees and its consultants to exercise options granted under the Prior Plan prior to vesting. The shares related to early exercised stock options are subject to the Company’s lapsing repurchase right upon termination of employment or service on the Board of Directors at the lesser of the original purchase price or fair market value at the time of repurchase. In order to vest, the holders are required to provide continued service to the Company. The early exercise by an employee or consultant of a stock option is not considered to be a substantive exercise for accounting purposes, and therefore the payment received by the employer for the exercise price is recognized as a liability. For accounting purposes, unvested early exercised shares are not considered issued and outstanding and therefore not reflected as issued and outstanding in the accompanying balance sheets or the accompanying statements of stockholders' equity (deficit) until the awards vest.

The deposits received are initially recorded in current portion of other liabilities and other noncurrent liabilities for the noncurrent portion. The liabilities are reclassified to common stock and paid-in capital as the repurchase right lapses. At September 30, 2023 and December 31, 2022, there was $0.4 million and $0.9 million recorded in current portion of other liabilities, respectively. At September 30, 2023 and December 31, 2022, there was zero and $0.2 million recorded in other noncurrent liabilities, respectively, related to shares held by employees and nonemployees that were subject to repurchase.

Property and Equipment, Net (Details) - USD ($)

3 Months Ended

9 Months Ended

Sep. 30, 2023

Sep. 30, 2022

Sep. 30, 2023

Sep. 30, 2022

Dec. 31, 2022

Property and equipment:

Property, plant and equipment, gross

$ 18,483,000

$ 18,500,000

Less: Accumulated depreciation

(7,173,000)

(5,515,000)

Total property and equipment, net

11,310,000

12,985,000

^[1]

Depreciation

500,000

$ 600,000

1,658,000

$ 1,692,000

Impairment of long-lived assets, related leasehold improvements

$ 0

600,000

$ 0

Lab equipment

Property and equipment:

Property, plant and equipment, gross

9,090,000

8,475,000

Leasehold improvements

Property and equipment:

Property, plant and equipment, gross

8,703,000

9,348,000

Furniture and fixtures

Property and equipment:

Property, plant and equipment, gross

619,000

Computer equipment

Property and equipment:

Property, plant and equipment, gross

$ 71,000

$ 58,000

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Accrued Expenses and Current Portion of Other Liabilities

9 Months Ended

Sep. 30, 2023

Payables and Accruals [Abstract]

ACCRUED EXPENSES AND CURRENT PORTION OF OTHER LIABILITIES

Accrued expenses consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Accrued compensation	$	3,702	$	4,277
External research and development	4,023		7,694
Accrued outside services	1,055		945
Accrued taxes	—		40
Other accrued expenses	371		7
Total accrued expenses	$	9,151	$	12,963

Current portion of other liabilities consist of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Current portion of unvested early exercised share liability	$	350	$	891
ESPP withholdings	249		238
Total current portion of other liabilities	$	599	$	1,129

Nature of Operations and Basis of Presentation	9 Months Ended
Nature of Operations and Basis of Presentation	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF OPERATIONS AND BASIS OF PRESENTATION	NATURE OF OPERATIONS AND BASIS OF PRESENTATION Kronos Bio, Inc. (Kronos or the Company), a Delaware corporation, was incorporated on June 2, 2017. The Company is an integrated discovery through clinical development biopharmaceutical company, with a focus on developing therapeutics that target the dysregulated transcription that causes cancer and other serious diseases. The Company operates in one business segment: the development of biopharmaceutical products. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Unaudited Interim Financial Information The accompanying condensed balance sheet as of September 30, 2023, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022, the condensed statements of stockholders’ equity (deficit) as of September 30, 2023 and 2022, the condensed statements of cash flows for the nine months ended September 30, 2023 and 2022, and the financial data and other financial information disclosed in the notes to the condensed financial statements are unaudited. The unaudited interim condensed financial statements have been prepared on a basis consistent with the Company’s audited annual financial statements and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2023 and the results of its operations for the three and nine months ended September 30, 2023 and 2022. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the full year ending December 31, 2023, any other interim periods, or any future year or period. These condensed financial statements should be read in conjunction with the Company's audited financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 15, 2023 (Annual Report) Need for Additional Capital The Company has incurred net losses since its inception of $483.5 million as of September 30, 2023. The Company expects that its cash, cash equivalents and investments as of September 30, 2023 will be sufficient to fund its operations for a period of at least one year from the date of issuance of these condensed financial statements. Management expects to incur additional losses in the future to fund its operations and conduct product research and development and recognizes the need to raise additional capital. The Company intends to raise additional capital through the issuance of equity securities, debt financings or other sources in order to continue its operations. However, if such financing is not available when needed and at adequate levels, the Company will need to reevaluate its operating plan and may be required to delay the development of its product candidates. The future viability of the Company is dependent on its ability to generate cash from operating activities or to raise additional capital to finance its operations. The Company’s failure to raise capital as and when needed could have a material adverse effect on its financial condition and ability to pursue business strategies. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaboration arrangements or obtain government grants. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce, or eliminate its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects. In the event that the Company requires additional funding, there can be no assurance that it will be successful in obtaining sufficient funding on terms acceptable to the Company to fund its continuing operations, if at all.

Commitment and Contingencies	9 Months Ended
Commitment and Contingencies	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Amended Research and Development Services Agreement In October 2021, as subsequently amended in April 2023, the Company entered into an agreement for research and development services (the Amended Tempus Agreement) with Tempus Labs, Inc. (Tempus), pursuant to which Tempus agreed to provide the Company with research and development services for a period of four years. The three primary services are analytical services, data licensing, and organoid services. The Company intends to utilize the services contemplated under the Amended Tempus Agreement to advance the development of KB-0742 and lanraplenib. In consideration for the access to the services throughout the term of the Amended Tempus Agreement, the Company has agreed to pay an annual minimum commitment of $1.5 million in year one, $2.5 million in year two, $3.0 million in year three and $2.5 million in year four. Payments are made in quarterly installments. As of September 30, 2023, the Company has paid cumulatively $4.0 million under the Amended Tempus Agreement, including $2.9 million paid for the nine months ended September 30, 2023, $1.1 million paid for the year ended December 31, 2022 and null for the year ended December 31, 2021. In addition, the Company is required to make milestone payments upon successful achievement of certain regulatory milestones for KB-0742, lanraplenib, and other discovery pipeline compounds up to a combined maximum of $22.4 million. For each milestone payment that becomes due, the Company has the right to pay up to 50% of such milestone payment amount in shares of its common stock as long as certain regulatory requirements are met. As of September 30, 2023 and December 31, 2022, the Company determined that achievement of the milestones is not probable and therefore no corresponding liability has been recorded. Asset Purchase Agreement In July 2020, the Company entered into an asset purchase agreement (Gilead Asset Purchase Agreement) with Gilead Sciences, Inc. (Gilead), pursuant to which the Company acquired certain assets from Gilead related to entospletinib and lanraplenib, and patents and other intellectual property covering or related to the development, manufacture and commercialization of entospletinib and lanraplenib. Under the agreement, the Company is required to make milestone payments upon successful achievement of certain regulatory and sales milestones for lanraplenib, entospletinib and other SYK inhibitor compounds covered by the patent rights acquired pursuant to the Gilead Asset Purchase Agreement and developed by us as a back-up to entospletinib or lanraplenib (Other Compounds). Upon successful completion of certain regulatory milestones in the United States, European Union and United Kingdom for lanraplenib, entospletinib and any Other Compounds, across up to two distinct indications, we will be required to pay to Gilead an aggregate total of $51.3 million. Upon achieving certain thresholds for the aggregate annual net sales of lanraplenib, entospletinib, and any Other Compounds combined, we would owe to Gilead potential milestone payments totaling $115.0 million. Gilead is also eligible to receive (i) tiered marginal royalties ranging from high-single digits to the mid-teens on annual worldwide net sales of lanraplenib, (ii) tiered marginal royalties ranging from the very low-teens to high-teens on annual worldwide net sales of entospletinib, and (iii) tiered marginal royalties ranging from the low single digits to mid-single digits on annual worldwide net sales of any Other Compounds. The royalties in the foregoing clauses are subject to reduction, on a country-by-country basis, for products not covered by certain claims within the assigned patents, for generic entry and, in the case of lanraplenib and entospletinib, for any royalties paid for future licenses of third-party intellectual property required to develop or commercialize lanraplenib or entospletinib. Our royalty obligation with respect to a given product in a given country begins upon the first commercial sale of such product in such country and ends on the latest of (i) expiration of the last claim of a defined set of the assigned patent rights covering such product in such country, (ii) loss of exclusive data or marketing rights to such product in such country or (iii) 10 years from the first commercial sale of such product in such country. Under the Gilead Asset Purchase Agreement, we are required to use commercially reasonable efforts to develop, obtain regulatory approval for and commercialize either lanraplenib or entospletinib. We are currently unable to estimate the timing or likelihood of achieving remaining milestones or generating future product sales. Purchase Commitments In the normal course of business, the Company enters into contracts with contract research organizations (CROs) for preclinical and clinical studies and other vendors for services and products. These agreements generally provide for termination or cancellation, other than for costs already incurred and certain wind down costs that may be associated with the termination of a contract or clinical trial program. Contingencies In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications. The Company’s exposure under these agreements is unknown, because it involves claims that may be made against the Company in the future, but have not yet been made. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. Indemnification In accordance with the Company’s amended and restated certificate of incorporation and amended and restated bylaws, the Company has indemnification obligations to its officers and directors for certain events or occurrences, subject to certain limits, while they are serving in such capacity. There have been no claims to date, and the Company has a directors and officers liability insurance policy that may enable it to recover a portion of any amounts paid for future claims.

Fair Value Measurements (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 169,450	$ 233,551
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	24,864	49,003
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	975	490
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	1,667
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	9,299	30,657
U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	6,073	13,000
U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	128,239	138,734
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	154,078	188,227
Level 1 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	24,864	49,003
Level 1 \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	975	490
Level 1 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 1 \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 1 \| U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 1 \| U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	128,239	138,734
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	15,372	45,324
Level 2 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Level 2 \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 2 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	1,667
Level 2 \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	9,299	30,657
Level 2 \| U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	6,073	13,000
Level 2 \| U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Level 3 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Level 3 \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3 \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3 \| U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3 \| U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 0	$ 0

Prepaid Expenses And Other Current Assets

9 Months Ended

Sep. 30, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

PREPAID EXPENSES AND OTHER CURRENT ASSETS

PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Accrued interest on short-term available-for-sale securities	$	492	$	572
Prepaid equipment service contracts	281		289
Prepaid external research and development and outside services	2,175		2,276
Prepaid software	1,117		905
Prepaid insurance	111		1,630
Other prepaid expenses	674		434
Total prepaid expenses and other current assets	$	4,850	$	6,106

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (87,353)	$ (101,422)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation	1,658	1,692
Net amortization (accretion) on available-for-sale securities	(4,103)	185
Change in accrued interest on available-for-sale securities	363	856
Stock-based compensation expense	19,809	23,456
Noncash lease expense	1,982	1,628
Impairment of long-lived assets	2,916	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,266	1,433
Other noncurrent assets	197	0
Accounts payable	(945)	409
Accrued expenses	(3,812)	6,161
Right-of-use operating assets and lease liabilities, net	(1,549)	(1,997)
Deferred revenue	15,999	0
Current portion of other liabilities and other noncurrent liabilities	14	(799)
Net cash provided by (used in) operating activities	(53,558)	(68,398)
Cash flows from investing activities:
Purchase of property and equipment	(648)	(525)
Purchase of available-for-sale marketable securities	(170,816)	(307,181)
Maturities of marketable securities	206,272	243,248
Sale of marketable securities	0	500
Net cash provided by (used in) investing activities	34,808	(63,958)
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options	28	1,532
Proceeds from issuance of common stock under the employee stock purchase plan	348	35
Net cash provided by (used in) financing activities	376	1,567
Net increase (decrease) in cash and cash equivalents	(18,374)	(130,789)
Cash, cash equivalents and restricted cash at beginning of period	77,999	200,296
Cash, cash equivalents and restricted cash at end of period	59,625	69,507
Supplemental disclosures of non-cash activities:
Property and equipment additions included in accounts payable and accrued expenses	0	51
Cash and cash equivalents at end of period	57,599	67,481
Restricted cash at end of period	2,026	2,026
Cash, cash equivalents and restricted cash at end of period	$ 59,625	$ 69,507

Investments (Tables)

9 Months Ended

Sep. 30, 2023

Investments, Debt and Equity Securities [Abstract]

Investments Classified by Contractual Maturity Date

The fair value and amortized cost of available-for-sale securities by major security type as of September 30, 2023 and December 31, 2022 were as follows (in thousands):


	September 30, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	24,864	$	—	$	—	$	24,864
Certificates of deposit	980		—		(5)		975
Commercial paper	—		—		—		—
Corporate bonds	9,306		—		(7)		9,299
U.S. agency securities	6,075		1		(3)		6,073
U.S. treasury securities	128,480		2		(243)		128,239
Total cash equivalents and investments	$	169,705	$	3	$	(258)	$	169,450


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	49,003	$	—	$	—	$	49,003
Certificates of deposit	490		—		—		490
Commercial paper	1,667		—		—		1,667
Corporate bonds	30,683		3		(29)		30,657
U.S. agency securities	13,024		—		(24)		13,000
U.S. treasury securities	139,477		4		(747)		138,734
Total cash equivalents and investments	$	234,344	$	7	$	(800)	$	233,551

These available-for-sale securities were classified on the Company’s condensed balance sheets as of September 30, 2023 and December 31, 2022 as (in thousands):


	Fair Value
	September 30, 2023		December 31, 2022
Cash equivalents	$	28,666	$	61,577
Short-term investments	129,114		162,212
Long-term investments	11,670		9,762
Total cash equivalents and investments	$	169,450	$	233,551

The fair values of available-for-sale securities by contractual maturity as of September 30, 2023 and December 31, 2022 were as follows (in thousands):


	September 30, 2023		December 31, 2022
Due in 1 year or less	$	132,917	$	174,786
Due in 1 to 2 years	11,670		9,762

Total	$	144,587	$	184,548

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	12,975,842	10,914,210
Stock options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	8,843,067	7,362,762
Early exercised stock options subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	98,190	386,862
Restricted stock awards subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	28,577	62,870
Restricted stock units subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	2,503,507	2,271,896
Expected shares to be purchased under Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	1,502,501	829,820

Significant Accounting Policies, Estimates and Judgments	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS	SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS Significant Accounting Policies In 2023, the Company began to recognize revenue related to research and development services and licenses. Refer below for a description of the revenue recognition policy. There have been no additional changes to the accounting policies during the nine months ended September 30, 2023, as compared to the significant accounting policies described in Note 2 of the “Notes to Financial Statements” of the Company’s audited financial statements included in its Annual Report for the year ended December 31, 2022. Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of assets and liabilities at the date of the condensed financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed financial statements include, but are not limited to, revenue, the accrual of research and development expenses, the fair value of investments, the fair value of the Company’s long-lived assets, income tax uncertainties, the valuation of equity instruments and the incremental borrowing rate for determining the operating lease assets and liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates. Revenue Recognition The Company recognizes revenue in accordance with the provisions of Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”). The Company recognizes revenue when the Company’s customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods and services. To determine revenue recognition for arrangements within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when or as the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. The Company evaluates the promised goods or services in these agreements to determine which ones represent distinct performance obligations. These agreements may include the following types of promised goods or services: (i) grants of licenses and related transfer of know-how, (ii) performance of research and development services, and (iii) participation on joint research and/or development committees. They also may include options to obtain further research and development services and licenses to the Company’s intellectual property. The payment terms of these agreements may include nonrefundable upfront fees, payments for electing the contractual options, payments based upon the achievement of certain milestones, and royalty payments based on product sales derived from the collaboration. The Company exercises judgment in assessing those promised goods and services that are distinct and thus representative of performance obligations. To the extent the Company identifies multiple performance obligations in a contract, the Company must develop assumptions that require judgment to determine the estimated standalone selling price for each performance obligation in order to allocate the transaction price among the identified performance obligations. The transaction is allocated on a relative standalone selling price basis. Prior to recognizing revenue, the Company makes estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. These estimates are reassessed each reporting period as required. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligations when or as the performance obligations are satisfied. For performance obligations satisfied over time, the Company estimates the efforts needed to complete the performance obligations and recognizes revenue by measuring the progress towards complete satisfaction of the performance obligations using an input measure. The estimated period of performance and level of effort, including the value of the Company researchers’ time and third-party costs, are reviewed quarterly and adjusted, as needed, to reflect the Company’s current expectations. The measurement of progress is then used to calculate revenue, including any revenue adjustments as a result of the change in estimate. For arrangements that include sales-based royalties, including commercial milestone payments based on pre-specified level of sales, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligations to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). Achievement of these royalties and commercial milestones may solely depend upon the performance of the licensee. Funds received in advance are recorded as deferred revenue and are recognized as the related performance obligations are satisfied. There are no performance, cancellation, termination, or refund provisions in any of the arrangements that contain material financial consequences to the Company. Recent Accounting Pronouncements The Company continues to monitor new accounting pronouncements issued by the Financial Accounting Standards Board and does not believe any accounting pronouncements issued, and not yet adopted, through the date of this report will have a material impact on the Company's consolidated financial statements.

Prepaid Expenses And Other Current Assets (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Accrued interest on short-term available-for-sale securities

$ 492

$ 572

Prepaid equipment service contracts

281

289

Prepaid external research and development and outside services

2,175

2,276

Prepaid software

1,117

905

Prepaid insurance

111

1,630

Other prepaid expenses

674

434

Total prepaid expenses and other current assets

$ 4,850

$ 6,106

^[1]

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Stock-Based Compensation - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2020	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value, options granted (in dollars per share)				$ 1.41
Stock options, unrecognized cost		$ 20,200,000		$ 20,200,000		$ 35,400,000
Stock-based compensation expense		6,296,000	$ 7,461,000	19,809,000	$ 23,456,000
Current liabilities related to shares that were subject to repurchase		350,000		350,000		891,000
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		3,059,000	$ 3,961,000	10,337,000	$ 12,101,000
Current portion of other liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Current liabilities related to shares that were subject to repurchase		400,000		400,000		900,000
Other noncurrent liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-current liabilities related to shares that were subject to repurchase		$ 0		$ 0		$ 200,000
2020 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Shares that may be issued, percent increase as total of common stock outstanding	5.00%
Number of shares that may have been issued (in shares)		20,417,192		20,417,192
Options, exercise price, percent of fair market value	100.00%
Vesting period	4 years
Number of shares reserved for future issuance (in shares)		4,260,124		4,260,124
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options recognized, weighted average period				1 year 10 months 20 days		2 years 3 months
Expected shares to be purchased under Employee Stock Purchase Plan \| The ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares that may have been issued (in shares)	688,000
Number of shares that may be issued, increase percentage	1.00%
Number of shares that may be issued, increase (in shares)	1,376,000
Employee stock purchase plan (in shares)		0	0	247,048	12,539
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock based compensation		$ 6,600,000		$ 6,600,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock based compensation		$ 100,000		$ 100,000

Net Loss Per Share

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

NET LOSS PER SHARE

The following table summarizes the computation of basic and diluted net loss per share of the Company for the three and nine months ended September 30, 2023 and 2022 (in thousands, except share and per share amounts):


	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Net loss	$	(31,374)	$	(32,256)	$	(87,353)	$	(101,422)
Weighted-average common stock outstanding, basic and diluted	58,146,306		56,318,571		57,567,489		56,093,091
Net loss per share, basic and diluted	$	(0.54)	$	(0.57)	$	(1.52)	$	(1.81)

The Company’s potentially dilutive securities, which include options to purchase shares of the Company's common stock and restricted stock subject to future vesting, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share.

The Company excluded the following potential shares of common stock, presented based on amounts outstanding at each stated period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


	September 30, 2023	September 30, 2022
Stock options to purchase common stock	8,843,067	7,362,762
Early exercised stock options subject to future vesting	98,190	386,862
Restricted stock awards subject to future vesting	28,577	62,870
Restricted stock units subject to future vesting	2,503,507	2,271,896

Expected shares to be purchased under Employee Stock Purchase Plan	1,502,501	829,820
Total	12,975,842	10,914,210

In addition to the potentially dilutive securities noted above, the Company also has the option under its agreement with Tempus to issue common shares upon the achievement of specified milestones. Please refer to Note 11, “Commitment and Contingencies” for further details. Because the necessary conditions for issuance of the shares had not been met as of September 30, 2023, the Company excluded these shares from the table above.

Related Parties (Details) - USD ($)	3 Months Ended		9 Months Ended
Related Parties (Details) - USD ($)	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Service Agreement, Charges
Related Party Transaction [Line Items]
Expenses from transaction with related party	$ 24,000	$ 30,000	$ 72,000	$ 71,000
Consulting Agreement
Related Party Transaction [Line Items]
Expenses from transaction with related party	$ 6,300	$ 6,300	$ 18,900	$ 18,900

Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net loss	$ (31,374)	$ (29,741)	$ (26,238)	$ (32,256)	$ (32,903)	$ (36,263)	$ (87,353)	$ (101,422)
Weighted-average common stock outstanding, basic (in shares)	58,146,306			56,318,571			57,567,489	56,093,091
Weighted-average common stock outstanding, diluted (in shares)	58,146,306			56,318,571			57,567,489	56,093,091
Net loss per share, basic (in dollars per share)	$ (0.54)			$ (0.57)			$ (1.52)	$ (1.81)
Net loss per share, diluted (in dollars per share)	$ (0.54)			$ (0.57)			$ (1.52)	$ (1.81)

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-10

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482765/220-10-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-8

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-9

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480167/946-830-55-10

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483581/946-220-45-7

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(9))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 32: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483499/205-20-50-7

Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock Option Activity

Stock option activity under the 2020 Plan as of September 30, 2023 is summarized as follows:


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
				(in years)	(in thousands)
Balance, December 31, 2022	7,454,665	$	11.83	7.69	$	54
Granted	3,200,631	1.99
Forfeited	(1,471,660)	10.94
Exercised	(242,379)	3.21
Balance, September 30, 2023	8,941,257	$	8.69	8.00	$	17

Schedule of Nonvested Share Activity

Restricted stock awards and restricted stock units as of September 30, 2023 are summarized as follows:


	Number of Restricted Stock	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Vesting Life	Aggregate Intrinsic Value
				(in years)	(in thousands)
Unvested, December 31, 2022	2,297,745	$	9.18	1.58	$	3,722
Granted	1,611,211	1.99
Vested and converted to shares	(723,876)	8.21
Forfeited	(652,996)	5.25
Unvested, September 30, 2023	2,532,084	$	5.90	1.08	$	3,292

Stock-based Compensation, Classified in Statements of Operations


	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Research and development expenses	$	3,237	$	3,500	$	9,472	$	11,355
General and administrative expenses	3,059		3,961		10,337		12,101
Total stock-based compensation expense	$	6,296	$	7,461	$	19,809	$	23,456

Condensed Statements of Stockholders’ Equity (Deficit) (Unaudited) - USD ($)
$ in Thousands

Total

Common Stock

Additional Paid-in Capital

Accumulated Other Comprehensive Income (Loss)

Accumulated Deficit

Common stock, beginning balance (in shares) at Dec. 31, 2021

55,703,327

Beginning balance at Dec. 31, 2021

$ 345,097

$ 56

$ 608,064

$ (39)

$ (262,984)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)

361,182

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock

529

Stock-based compensation expense

7,788

Net unrealized gain (loss) on available-for-sale securities

(131)

Net loss

(36,263)

Common stock, ending balance (in shares) at Mar. 31, 2022

56,064,509

Beginning balance at Mar. 31, 2022

317,020

$ 56

616,381

(170)

(299,247)

Common stock, beginning balance (in shares) at Dec. 31, 2021

55,703,327

Beginning balance at Dec. 31, 2021

345,097

$ 56

608,064

(39)

(262,984)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Net unrealized gain (loss) on available-for-sale securities

(1,011)

Net loss

(101,422)

Common stock, ending balance (in shares) at Sep. 30, 2022

56,439,628

Beginning balance at Sep. 30, 2022

267,687

$ 56

633,087

(1,050)

(364,406)

Common stock, beginning balance (in shares) at Mar. 31, 2022

56,064,509

Beginning balance at Mar. 31, 2022

317,020

$ 56

616,381

(170)

(299,247)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)

142,189

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock

375

Stock-based compensation expense

8,207

Employee stock purchase plan (in shares)

12,539

Employee stock purchase plan

Net unrealized gain (loss) on available-for-sale securities

(491)

Net loss

(32,903)

Common stock, ending balance (in shares) at Jun. 30, 2022

56,219,237

Beginning balance at Jun. 30, 2022

292,243

$ 56

624,998

(661)

(332,150)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)

220,391

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock

628

Stock-based compensation expense

7,461

Net unrealized gain (loss) on available-for-sale securities

(389)

Net loss

(32,256)

Common stock, ending balance (in shares) at Sep. 30, 2022

56,439,628

Beginning balance at Sep. 30, 2022

$ 267,687

$ 56

633,087

(1,050)

(364,406)

Common stock, beginning balance (in shares) at Dec. 31, 2022

56,967,436

Beginning balance at Dec. 31, 2022

$ 244,499

^[1]

$ 57

641,422

(792)

(396,188)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)

386,318

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock

305

Stock-based compensation expense

6,607

Net unrealized gain (loss) on available-for-sale securities

432

Net loss

(26,238)

Common stock, ending balance (in shares) at Mar. 31, 2023

57,353,754

Beginning balance at Mar. 31, 2023

$ 225,605

$ 57

648,334

(360)

(422,426)

Common stock, beginning balance (in shares) at Dec. 31, 2022

56,967,436

Beginning balance at Dec. 31, 2022

$ 244,499

^[1]

$ 57

641,422

(792)

(396,188)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Net unrealized gain (loss) on available-for-sale securities

537

Net loss

$ (87,353)

Common stock, ending balance (in shares) at Sep. 30, 2023

58,180,739

Beginning balance at Sep. 30, 2023

$ 178,620

$ 58

662,358

(255)

(483,541)

Common stock, beginning balance (in shares) at Mar. 31, 2023

57,353,754

Beginning balance at Mar. 31, 2023

225,605

$ 57

648,334

(360)

(422,426)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)

521,497

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock

333

$ 1

332

Stock-based compensation expense

6,906

Employee stock purchase plan (in shares)

247,048

Employee stock purchase plan

348

Net unrealized gain (loss) on available-for-sale securities

(109)

Net loss

(29,741)

Common stock, ending balance (in shares) at Jun. 30, 2023

58,122,299

Beginning balance at Jun. 30, 2023

203,342

$ 58

655,920

(469)

(452,167)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)

58,440

Issuance of common stock upon vesting and exercise of options and vesting of restricted stock

142

Stock-based compensation expense

6,296

Net unrealized gain (loss) on available-for-sale securities

214

Net loss

$ (31,374)

(31,374)

Common stock, ending balance (in shares) at Sep. 30, 2023

58,180,739

Beginning balance at Sep. 30, 2023

$ 178,620

$ 58

$ 662,358

$ (255)

$ (483,541)

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Leases - Additional Information (Details)

1 Months Ended

3 Months Ended

9 Months Ended

Feb. 28, 2021

USD ($)

ft²

Mar. 31, 2020

USD ($)

ft²

Sep. 30, 2023

USD ($)

Sep. 30, 2022

USD ($)

Sep. 30, 2023

USD ($)

Sep. 30, 2022

USD ($)

Dec. 31, 2022

USD ($)

Lessee, Lease, Description [Line Items]

Operating lease right-of-use assets

$ 20,454,000

$ 24,707,000

^[1]

Lease liabilities

29,542,000

31,091,000

Lease payments

1,300,000

$ 1,900,000

3,700,000

$ 4,200,000

Impairment of long-lived assets

2,916,000

Impairment of long-lived assets, right-of-use asset

2,300,000

Impairment of long-lived assets, related leasehold improvements

600,000

Impairment charge

$ 0

Research and development expenses

Lessee, Lease, Description [Line Items]

Impairment of long-lived assets

1,900,000

General and administrative expenses

Lessee, Lease, Description [Line Items]

Impairment of long-lived assets

1,000,000

301 Binney Street, Cambridge, Massachusetts

Lessee, Lease, Description [Line Items]

Lease term

11 years

Facility size | ft²

40,514

Initial annual base rent

$ 4,100,000

Escalating rent payments, percent

3.00%

Letter of credit

$ 2,000,000

Tenant improvement allowances

$ 3,700,000

Improvement costs incurred, reimbursed by lessor

3,700,000

Operating lease right-of-use assets

18,600,000

21,900,000

Lease liabilities

$ 26,500,000

28,000,000

Remaining lease term

7 years 5 months

Incremental borrowing rate

8.50%

San Mateo, California. February 2021 Lease Agreement

Lessee, Lease, Description [Line Items]

Facility size | ft²

17,340

Initial annual base rent

$ 1,200,000

Escalating rent payments, percent

3.00%

Operating lease right-of-use assets

$ 1,900,000

2,800,000

Lease liabilities

$ 3,100,000

$ 3,700,000

Remaining lease term

2 years 9 months

Incremental borrowing rate

11.18%

Security deposit

$ 59,000

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Condensed Balance Sheets (Unaudited) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

^[1]

Current assets:

Cash and cash equivalents

$ 57,599

$ 75,973

Short-term investments

129,114

162,212

Prepaid expenses and other current assets

4,850

6,106

Total current assets

191,563

244,291

Long-term investments

11,670

9,762

Property and equipment, net

11,310

12,985

Operating lease right-of-use assets

20,454

24,707

Restricted cash

2,026

Other noncurrent assets

970

1,167

Total assets

237,993

294,938

Current liabilities:

Accounts payable

4,082

5,047

Accrued expenses

9,151

12,963

Current portion of operating lease liabilities

3,263

2,347

Current portion of deferred revenue

8,577

Current portion of other liabilities

599

1,129

Total current liabilities

25,672

21,486

Noncurrent operating lease liabilities

26,279

28,744

Deferred revenue, net of current portion

7,422

Other noncurrent liabilities

209

Total liabilities

59,373

50,439

Commitments and contingencies (Note 11)

Stockholders’ equity:

Common stock, $0.001 par value, 200,000,000 authorized as of September 30, 2023 and December 31, 2022; 58,180,739 and 56,967,436 shares issued and outstanding as of September 30, 2023 and December 31, 2022, respectively.

Preferred stock, $0.001 par value; 10,000,000 authorized; no shares issued and outstanding.

Additional paid-in capital

662,358

641,422

Accumulated deficit

(483,541)

(396,188)

Accumulated other comprehensive income (loss)

(255)

(792)

Total stockholders' equity

178,620

244,499

Total liabilities and stockholders’ equity

$ 237,993

$ 294,938

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Investments - Balance Sheet (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Cash equivalents

$ 28,666

$ 61,577

Short-term investments

129,114

162,212

^[1]

Long-term investments

11,670

9,762

^[1]

Total cash equivalents and investments

$ 169,450

$ 233,551

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Collaboration and License Agreement (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 06, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue		$ 917	$ 0	$ 4,002	$ 0
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration and license agreement, termination notice period, prior written notice	60 days
Collaboration and license agreement, termination notice period, uncured material breach	90 days
Collaboration and license agreement, termination notice period, uncured material breach, nonpayment	45 days
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected timing of satisfaction, extension period	6 months
Genentech, Inc. \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-07
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected timing of satisfaction, period	24 months
Genentech, Inc. \| License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment	$ 20,000	$ 16,000		$ 16,000
Maximum aggregate milestone payments	177,000
Maximum aggregate milestone payments from net sales	$ 100,000

Commitment and Contingencies (Details) $ in Millions	1 Months Ended		9 Months Ended	12 Months Ended		24 Months Ended
Commitment and Contingencies (Details) $ in Millions	Apr. 30, 2023 USD ($) service	Jul. 31, 2020 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2023 USD ($)
Tempus Labs, Inc.
Schedule Of Asset Acquisition [Line Items]
Payments to purchase obligation			$ 2.9	$ 1.1	$ 0.0	$ 4.0
Research And Development Services \| Tempus Labs, Inc.
Schedule Of Asset Acquisition [Line Items]
Services contract term	4 years
Number of primary services \| service	3
Annual minimum commitment payment in year one	$ 1.5
Annual minimum commitment payment in year two	2.5
Annual minimum commitment payment in year three	3.0
Annual minimum commitment payment in year four	2.5
Sales milestone payment	$ 22.4
Sales milestone payment in shares of common stock, percent threshold	50.00%
Asset Purchase Agreement
Schedule Of Asset Acquisition [Line Items]
Regulatory milestone payment		$ 51.3
Aggregate annual net sales, milestone payment		$ 115.0
Royalty Agreement Terms
Schedule Of Asset Acquisition [Line Items]
Years from first commercial sale of product		10 years

Fair Value Measurements

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

The Company follows authoritative accounting guidance, which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability.

The Company measures and reports its cash equivalents and investments at fair value.

Money market funds are measured at fair value on a recurring basis using quoted prices and are classified as Level 1. Investments measured at fair value based on inputs other than quoted prices that are derived from observable market data are classified as Level 2.

Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of September 30, 2023 and December 31, 2022 were as follows (in thousands):


	September 30, 2023
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	24,864	$	—	$	—	$	24,864
Certificates of deposit	975		—		—		975
Commercial paper	—		—		—		—
Corporate bonds	—		9,299		—		9,299
U.S. agency securities	—		6,073		—		6,073
U.S. treasury securities	128,239		—		—		128,239
Total financial assets	$	154,078	$	15,372	$	—	$	169,450


	December 31, 2022
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	49,003	$	—	$	—	$	49,003
Certificates of deposit	490		—		—		490
Commercial paper	—		1,667		—		1,667
Corporate bonds	—		30,657		—		30,657
U.S. agency securities	—		13,000		—		13,000
U.S. treasury securities	138,734		—		—		138,734
Total financial assets	$	188,227	$	45,324	$	—	$	233,551

The carrying amounts of accounts payable and accrued expenses approximate their fair values due to their short-term maturities. The Company’s Level 2 securities are valued using third-party pricing sources. The pricing services utilize industry standard valuation models, including both income- and market-based approaches, for which all significant inputs are observable, either directly or indirectly.

The Company did not have any financial assets or liabilities as of September 30, 2023 and December 31, 2022 that required Level 3 inputs.

- 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

Leases - Supplemental Balance Sheet Information - Operating Leases (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Assets:

Operating lease assets

$ 20,454

$ 24,707

^[1]

Liabilities:

Current portion of operating lease liabilities

3,263

2,347

^[1]

Noncurrent operating lease liabilities

26,279

28,744

^[1]

Total operating lease liabilities

$ 29,542

$ 31,091

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Property and Equipment, Net

9 Months Ended

Sep. 30, 2023

Property, Plant and Equipment [Abstract]

PROPERTY AND EQUIPMENT, NET

Property and equipment, net consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Property and equipment:
Lab equipment	$	9,090	$	8,475
Leasehold improvements	8,703		9,348
Furniture and fixtures	619		619

Computer equipment	71		58
Total property and equipment	18,483		18,500
Less: Accumulated depreciation	(7,173)		(5,515)
Total property and equipment, net	$	11,310	$	12,985

Depreciation expense was $0.5 million and $0.6 million for the three months ended September 30, 2023 and 2022, respectively and $1.7 million and $1.7 million for the nine months ended September 30, 2023 and 2022, respectively.

During the nine months ended September 30, 2023, the Company recognized a non-cash impairment charge of $0.6 million to Leasehold improvements. There was no charge in the three months ended September 30, 2023 and three and nine months ended September 30, 2022. Please refer to Note 12, “Leases”, section “Impairment of Operating Lease Right-of-Use Asset and Other Long-Lived Assets” for further details.

Leases (Tables)

9 Months Ended

Sep. 30, 2023

Leases [Abstract]

Assets and Liabilities, Operating Leases, Lessee

The following table summarizes the presentation of the Company’s operating leases in its balance sheets as of September 30, 2023 and December 31, 2022 (in thousands):


Balance Sheet Caption	September 30, 2023		December 31, 2022
Assets:
Operating lease assets	$	20,454	$	24,707
Liabilities:
Current portion of operating lease liabilities	$	3,263	$	2,347
Noncurrent operating lease liabilities	26,279		28,744
Total operating lease liabilities	$	29,542	$	31,091

Summary of Lease Costs

The following table summarizes the effect of operating lease costs in the Company’s statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022 (in thousands):


Statement of Operations and Comprehensive Loss Caption	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Research and development	$	897	$	767	$	2,431	$	2,301
General and administrative	561		511		1,582		1,532
Total operating lease cost	$	1,458	$	1,278	$	4,013	$	3,833

Schedule of Maturities on Lease Liabilities

The undiscounted future non-cancellable lease payments under the Company's operating leases as of September 30, 2023 for the next five years and thereafter is expected to be as follows (in thousands):


	Amount
Remaining three months of 2023	$	1,440
2024	5,749
2025	5,921
2026	5,405
2027 and thereafter	21,298
Total undiscounted lease payments	39,813
Less: Present value adjustment	(10,271)

Present value of operating lease liabilities	$	29,542

Stock-Based Compensation - Restricted Stock Awards Activity (Details) - Restricted Stock And Restricted Stock Units - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Number of Restricted Stock
Unvested Beginning Balance (in shares)	2,297,745
Granted - restricted stock awards and units (in shares)	1,611,211
Vested and converted to shares (in shares)	(723,876)
Forfeited (in shares)	(652,996)
Unvested Ending Balance (in shares)	2,532,084	2,297,745
Weighted-Average Grant Date Fair Value
Unvested Beginning Balance (in dollars per share)	$ 9.18
Granted - restricted stock awards and units (in dollars per share)	1.99
Vested and converted to shares (in dollars per share)	8.21
Forfeited (in dollars per share)	5.25
Unvested Ending Balance (in dollars per share)	$ 5.90	$ 9.18
Restricted Stock Awards, Additional Disclosures
Weighted-Average Remaining Vesting Life	1 year 29 days	1 year 6 months 29 days
Aggregate Intrinsic Value	$ 3,292	$ 3,722

Leases

9 Months Ended

Sep. 30, 2023

Leases [Abstract]

LEASES

LEASESIn March 2020, the Company entered into an 11-year lease agreement to move its research and development operations from 21 Erie Street, Cambridge, Massachusetts, to a 40,514 square-feet facility at 301 Binney Street, Cambridge, Massachusetts (Cambridge facility). The lease commenced on February 28, 2020 with an initial annual base rent of $4.1 million. The initial rent payment was paid as of September 30, 2020, with rent payments escalating 3.0% annually after the initial 12 payments. The Company executed a letter of credit for $2.0 million in connection with the lease. The lease includes $3.7 million in certain tenant improvement allowances, which the Company included in its calculation of the right-of-use asset in the lease at commencement. As of September 30, 2023, $3.7 million in improvement costs incurred by the Company were reimbursed by the lessor and are now included within the total lease liability. In connection with the lease, the Company recognized an operating lease right-of-use asset of $18.6 million and $21.9 million and an aggregate lease liability of $26.5 million and $28.0 million as of September 30, 2023 and December 31, 2022, respectively. The remaining lease term is 7 years and 5 months, and the estimated incremental borrowing rate is 8.50%.

In February 2021, the Company entered into a new lease agreement for its office space in San Mateo, California totaling 17,340 square-feet. The initial annual base rent for the new space was $1.2 million, and such amount increases by 3% annually on each anniversary of the new premises commencement date. In connection with the larger space leased, the Company made a one-time cash security deposit in the amount of $59,000. The lease commenced in April 2021 and terminates August 31, 2026. In connection with the lease, the Company recognized an operating lease right-of-use asset of $1.9 million and $2.8 million and an aggregate lease liability of $3.1 million and $3.7 million as of September 30, 2023 and December 31, 2022, respectively. The remaining lease term is 2 years and 9 months, and the estimated incremental borrowing rate is 11.18%.

The following table summarizes the presentation of the Company’s operating leases in its balance sheets as of September 30, 2023 and December 31, 2022 (in thousands):


Balance Sheet Caption	September 30, 2023		December 31, 2022
Assets:
Operating lease assets	$	20,454	$	24,707
Liabilities:
Current portion of operating lease liabilities	$	3,263	$	2,347
Noncurrent operating lease liabilities	26,279		28,744
Total operating lease liabilities	$	29,542	$	31,091


Statement of Operations and Comprehensive Loss Caption	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Research and development	$	897	$	767	$	2,431	$	2,301
General and administrative	561		511		1,582		1,532
Total operating lease cost	$	1,458	$	1,278	$	4,013	$	3,833

Under the lease agreements, the Company made cash payments of $1.3 million and $3.7 million during the three and nine months ended September 30, 2023, respectively. The Company made cash payments of $1.9 million and $4.2 million during the three and nine months ended September 30, 2022, respectively.


	Amount
Remaining three months of 2023	$	1,440
2024	5,749
2025	5,921
2026	5,405
2027 and thereafter	21,298
Total undiscounted lease payments	39,813
Less: Present value adjustment	(10,271)

Present value of operating lease liabilities	$	29,542

Impairment of Operating Lease Right-of-Use Asset and Other Long-Lived Assets

The Company evaluates the carrying value of long-lived assets, which include property and equipment and right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying

amounts of the asset may not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset or asset group and its eventual disposition are less than its carrying amount. Impairment, if any, is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value.

As a result of the sustained decline in the Company’s stock price, the Company determined an impairment indicator was present. The Company determined all of its long-lived assets represent a single asset group for the purpose of the long-lived asset impairment assessment. The Company concluded that the carrying value of the single asset group was not recoverable as it exceeded the future net undiscounted cash flows that are expected to be generated from the use and eventual disposition of the assets within the asset group. To allocate and recognize the impairment loss, the Company, with the assistance of a third-party valuation firm, determined the fair value of the Company using the adjusted net asset method under the cost approach. The implied allocated impairment loss to any individual asset within the long-lived asset group shall not reduce the carrying amount of that asset below its fair value. To determine the fair value of the individual assets within the asset group, the Company utilized the discounted cash flow method of the income approach and the indirect cost approach.

Based on this analysis, during the nine months ended September 30, 2023, the Company recognized a non-cash impairment charge of $2.9 million, including $2.3 million for the right-of-use assets and $0.6 million for the leasehold improvements (please see Note 6, “Property and Equipment, Net” for further details). The Company recorded $1.9 million in “Research and Development” and $1.0 million in “General and Administration”, based on the relative allocation of the operating lease costs and depreciation and amortization expense. No impairment charge was recorded for the three months ended September 30, 2023 and three and nine months ended September 30, 2022.

These represent a Level 3 nonrecurring fair value measurement. Calculating the fair value of the assets involves significant estimates and assumptions. These estimates and assumptions include, among others, projected future cash flows, risk-adjusted discount rates and market conditions. Changes in the factors and assumptions used could materially affect the amount of impairment loss recognized in the period the asset was considered impaired.

Nature of Operations and Basis of Presentation (Details)
$ in Thousands

9 Months Ended

Sep. 30, 2023

USD ($)

segment

Dec. 31, 2022

USD ($)

^[1]

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Number of operating segments | segment

Accumulated deficit | $

$ 483,541

$ 396,188

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Accrued Expenses And Current Portion Of Other Liabilities (Tables)

9 Months Ended

Sep. 30, 2023

Payables and Accruals [Abstract]

Schedule of Accrued Liabilities

Accrued expenses consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Accrued compensation	$	3,702	$	4,277
External research and development	4,023		7,694
Accrued outside services	1,055		945
Accrued taxes	—		40
Other accrued expenses	371		7
Total accrued expenses	$	9,151	$	12,963

Schedule of Other Current Liabilities

Current portion of other liabilities consist of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Current portion of unvested early exercised share liability	$	350	$	891
ESPP withholdings	249		238
Total current portion of other liabilities	$	599	$	1,129

Investments - Fair Value and Amortized Cost (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Money market funds, amortized cost	$ 28,666	$ 61,577
Unrealized Gains	3	7
Unrealized Losses	(258)	(800)
Fair Value	144,587	184,548
Total cash equivalents and investments, amortized cost	169,705	234,344
Total cash equivalents and investments, fair value	169,450	233,551
Money market funds
Schedule of Held-to-maturity Securities [Line Items]
Money market funds, amortized cost	24,864	49,003
Certificates of deposit
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	980	490
Unrealized Gains	0	0
Unrealized Losses	(5)	0
Fair Value	975	490
Commercial paper
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0	1,667
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	0	1,667
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	9,306	30,683
Unrealized Gains	0	3
Unrealized Losses	(7)	(29)
Fair Value	9,299	30,657
U.S. agency securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	6,075	13,024
Unrealized Gains	1	0
Unrealized Losses	(3)	(24)
Fair Value	6,073	13,000
U.S. treasury securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	128,480	139,477
Unrealized Gains	2	4
Unrealized Losses	(243)	(747)
Fair Value	$ 128,239	$ 138,734

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Stockholders’ equity:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	58,180,739	56,967,436
Common stock, shares outstanding (in shares)	58,180,739	56,967,436
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Prepaid Expenses And Other Current Assets (Tables)

9 Months Ended

Sep. 30, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Prepaid Expenses and Other Assets

Prepaid expenses and other current assets consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Accrued interest on short-term available-for-sale securities	$	492	$	572
Prepaid equipment service contracts	281		289
Prepaid external research and development and outside services	2,175		2,276
Prepaid software	1,117		905
Prepaid insurance	111		1,630
Other prepaid expenses	674		434
Total prepaid expenses and other current assets	$	4,850	$	6,106

Investments - Contractual Maturity (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Due in 1 year or less	$ 132,917,000	$ 174,786,000
Due in 1 to 2 years	11,670,000	9,762,000
Total cash equivalents and investments	$ 144,587,000	$ 184,548,000
Contractual securities, available-for-sale, term	2 years	2 years
Fair value of securities with continuous net unrealized loss position for more than 12 months	$ 12,400,000	$ 0
Accumulated loss on securities with continuous net unrealized loss position for more than 12 months	$ 44,000	$ 0

Subsequent Event	9 Months Ended
Subsequent Event	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT On October 30, 2023, the Board of Directors of the Company approved an approximately 19% reduction of its workforce as part of a strategic resource allocation, restructuring and cost containment plan. The workforce reduction was completed on November 2, 2023. In connection with the reduction in workforce, the Company expects to incur charges of approximately $1.8 million associated with cash severance payments in the fourth quarter of 2023, and up to approximately $0.3 million in charges associated with cash payments for COBRA reimbursement over as much as the next six months.

Stock-Based Compensation - Restricted Stock Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,296	$ 7,461	$ 19,809	$ 23,456
Research and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,237	3,500	9,472	11,355
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,059	$ 3,961	$ 10,337	$ 12,101

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Property and Equipment, Net (Tables)

9 Months Ended

Sep. 30, 2023

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property and equipment, net consisted of the following as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023		December 31, 2022
Property and equipment:
Lab equipment	$	9,090	$	8,475
Leasehold improvements	8,703		9,348
Furniture and fixtures	619		619

Computer equipment	71		58
Total property and equipment	18,483		18,500
Less: Accumulated depreciation	(7,173)		(5,515)
Total property and equipment, net	$	11,310	$	12,985

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2023
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company did not record any income tax expense for the three and nine months ended September 30, 2023 and 2022. The Company has incurred net operating losses for all the periods presented and has not reflected any benefit of such net operating loss carryforwards in the accompanying condensed financial statements. The Company has recorded a full valuation allowance against all of its deferred tax assets as it is not more likely than not that such assets will be realized in the near future. It is the Company’s policy to record penalties and interest related to income taxes as a component of income tax expense. The Company has not recorded any interest or penalties related to income taxes during the three and nine months ended September 30, 2023 and 2022. The Company has not identified any new uncertain tax positions as of September 30, 2023. Unrecognized tax benefits are not expected to change during the next 12 months. The reversal of the unrecognized tax benefits would not affect the effective tax rate. The Company is subject to examination by U.S. federal and state tax authorities for all years since its inception.

- 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
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Collaboration and License Agreement	9 Months Ended
Collaboration and License Agreement	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
COLLABORATION AND LICENSE AGREEMENT	COLLABORATION AND LICENSE AGREEMENT On January 6, 2023, the Company entered into a Collaboration and License Agreement with Genentech, Inc., a member of the Roche Group (“Genentech”). Pursuant to the agreement, the parties have agreed to initially collaborate on two discovery research programs in oncology, each focused on a designated transcription factor, to discover small-molecule GLP-Tox-ready candidates that modulate transcription factor targets selected by Genentech. Each discovery research program primarily consists of (i) a mapping phase with the goal of identifying the transcription regulatory network for such designated transcription factor, and (ii) a screening phase having the goal of identifying and characterizing multiple screening hits suitable for nomination as a preclinical development program. The Company leads discovery and research activities under the discovery research programs and uses its proprietary drug discovery platform, including the small molecule microarray (SMM), for hit finding. Following the completion of initial discovery and research activities, Genentech will have the exclusive right to pursue further preclinical and clinical development and commercialization of compounds identified in the discovery research programs and designated by Genentech (each, a “Hit Program”). Pursuant to the agreement, the Company received an upfront payment of $20.0 million from Genentech. In addition, the Company is eligible for additional milestone payments upon achievement of certain preclinical, clinical and regulatory (including first-sale) milestones, totaling up to $177 million for the first development candidate per Hit Program, and is eligible to receive net sales milestones of up to $100 million for the first licensed product per Hit Program. The Company is also eligible to receive tiered royalties in the low- to high-single digits on any products that are commercialized by Genentech as a result of the collaboration. The term of the discovery research programs under the agreement is up to 24 months, which may be extended by six months at the Company’s option subject to satisfying certain conditions. Unless earlier terminated, the agreement will remain in effect for each product licensed under the agreement until expiration of the royalty term for such licensed product. Genentech has the right to terminate this agreement in its entirety, or with respect to a particular discovery research program or Hit Program, in its sole discretion, at any time by providing 60 days’ advance written notice to the Company. Each party may also terminate the agreement upon the other party’s material breach that remains uncured for 90 days (or 45 days in the event of nonpayment), or in the event of certain insolvency events involving the other party. The Company evaluated the agreement and determined it was within the scope of ASC 606. The Company determined there were performance obligations to perform research and development services. Each consists of various exclusive and non-exclusive licenses to use the Company’s intellectual property and know-how, initial discovery activities, and substitution of the designated transcription factor. The Company also identified customer options contained within the contract to perform further research and development services and the renewal of the licenses that were deemed a material right as these involved a discount to Genentech that they would not have otherwise received. As a result, the material rights for various options were recognized as separate performance obligations and the transaction price was allocated to the material rights based on the relative standalone selling price, the identified discount and the probability that the customer will exercise the option or the option is cancelled. Amounts allocated to a material right are not recognized as revenue until the option is exercised. The transaction price was determined to consist of the upfront payment of $20.0 million. Potential development and regulatory milestones have been fully constrained. The Company is expected to perform research and development services for each selected target up until a defined point at which time Genentech will decide whether or not to exercise an option to nominate a development candidate and take over future development and commercialization. The Company concluded this is not a material right. Any consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur as these amounts have been determined to relate predominantly to the license granted to Genentech. The Company determined that the performance obligations to perform research and development services are satisfied over time, and therefore, the related revenue will be recognized as services are provided. The Company recognized $0.9 million and $4.0 million in revenue during the three and nine months ended September 30, 2023, respectively, using the cost-based input model related to the research and development activities associated with the identified performance obligations. The remaining $16.0 million of the upfront payment is included in short and long-term deferred revenue as of September 30, 2023 and will be recognized as the performance obligations are satisfied.

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
Income Taxes (Details) - USD ($)	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0	$ 0	$ 0
Interest on income taxes expense	0	0	0	0
Income tax penalties expense	$ 0	$ 0	$ 0	$ 0

- Definition

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

+ References + Details

Investments

9 Months Ended

Sep. 30, 2023

Investments, Debt and Equity Securities [Abstract]

INVESTMENTS

The fair value and amortized cost of available-for-sale securities by major security type as of September 30, 2023 and December 31, 2022 were as follows (in thousands):


	September 30, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	24,864	$	—	$	—	$	24,864
Certificates of deposit	980		—		(5)		975
Commercial paper	—		—		—		—
Corporate bonds	9,306		—		(7)		9,299
U.S. agency securities	6,075		1		(3)		6,073
U.S. treasury securities	128,480		2		(243)		128,239
Total cash equivalents and investments	$	169,705	$	3	$	(258)	$	169,450


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	49,003	$	—	$	—	$	49,003
Certificates of deposit	490		—		—		490
Commercial paper	1,667		—		—		1,667
Corporate bonds	30,683		3		(29)		30,657
U.S. agency securities	13,024		—		(24)		13,000
U.S. treasury securities	139,477		4		(747)		138,734
Total cash equivalents and investments	$	234,344	$	7	$	(800)	$	233,551

These available-for-sale securities were classified on the Company’s condensed balance sheets as of September 30, 2023 and December 31, 2022 as (in thousands):


	Fair Value
	September 30, 2023		December 31, 2022
Cash equivalents	$	28,666	$	61,577
Short-term investments	129,114		162,212
Long-term investments	11,670		9,762
Total cash equivalents and investments	$	169,450	$	233,551

The fair values of available-for-sale securities by contractual maturity as of September 30, 2023 and December 31, 2022 were as follows (in thousands):


	September 30, 2023		December 31, 2022
Due in 1 year or less	$	132,917	$	174,786
Due in 1 to 2 years	11,670		9,762

Total	$	144,587	$	184,548

As of September 30, 2023 and December 31, 2022, the remaining contractual maturities of available-for-sale securities were less than two years, respectively. There have been no significant realized losses on available-for-sale securities for any of the periods presented in the accompanying condensed financial statements. As of September 30, 2023 and December 31, 2022, securities with a fair value of $12.4 million and zero, respectively, were in a continuous net unrealized loss position of $44 thousand and zero, respectively, for more than 12 months. Unrealized losses on available-for-sale securities are not attributed to credit risk for any of the periods presented. The Company believes that it is more likely than not that investments in an unrealized loss position will be held until maturity and all interest and principal will be received. The Company believes that an allowance for credit losses is unnecessary because the unrealized losses on certain of the Company’s available-for-sale securities are due to market factors. To date, the Company has not recorded any impairment charges on available-for-sale securities.

Accrued Expenses And Current Portion Of Other Liabilities - Accrued Expenses (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Payables and Accruals [Abstract]

Accrued compensation

$ 3,702

$ 4,277

External research and development

4,023

7,694

Accrued outside services

1,055

945

Accrued taxes

Other accrued expenses

371

Total accrued expenses

$ 9,151

$ 12,963

^[1]

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2023	Nov. 08, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-39592
Entity Registrant Name	Kronos Bio, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-1895605
Entity Address, Address Line One	1300 So. El Camino Real
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	San Mateo
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94402
City Area Code	650
Local Phone Number	781-5200
Title of 12(b) Security	Common stock, $0.001 par value per share
Trading Symbol	KRON
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		58,316,520
Entity Central Index Key	0001741830
Current Fiscal Year End Date	--12-31
Document Fiscal Year End	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted


	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Net loss	$	(31,374)	$	(32,256)	$	(87,353)	$	(101,422)
Weighted-average common stock outstanding, basic and diluted	58,146,306		56,318,571		57,567,489		56,093,091
Net loss per share, basic and diluted	$	(0.54)	$	(0.57)	$	(1.52)	$	(1.81)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share


	September 30, 2023	September 30, 2022
Stock options to purchase common stock	8,843,067	7,362,762
Early exercised stock options subject to future vesting	98,190	386,862
Restricted stock awards subject to future vesting	28,577	62,870
Restricted stock units subject to future vesting	2,503,507	2,271,896

Expected shares to be purchased under Employee Stock Purchase Plan	1,502,501	829,820
Total	12,975,842	10,914,210

Accrued Expenses And Current Portion Of Other Liabilities - Current Other Liabilities (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Payables and Accruals [Abstract]

Current portion of unvested early exercised share liability

$ 350

$ 891

ESPP withholdings

249

238

Total current portion of other liabilities

$ 599

$ 1,129

^[1]

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Related Parties	9 Months Ended
Related Parties	Sep. 30, 2023
Related Party Transactions [Abstract]
RELATED PARTIES	RELATED PARTIES On December 1, 2017, the Company entered into a services agreement with Two River Consulting, LLC (Two River) to provide various clinical development, operational, managerial, accounting and financial, and administrative services to the Company. Arie Belldegrun, M.D., FACS, the Chairman of the Board of Directors, is the Chairman of Two River. Mr. Joshua Kazam and Mr. David Tanen, each a director of the Company, are each partners of Two River. Mr. Christopher Wilfong, a strategic advisor to the Company, is an Operating Partner of Two River and Mr. Sean Algeo, serving as a financial consultant to the Company, is the Chief Financial Officer of Two River. During the three and nine months ended September 30, 2023, the Company incurred expenses of $24,000 and $72,000, respectively, for these services. During the three and nine months ended September 30, 2022, the Company incurred expenses of $30,000 and $71,000, respectively, for these services. In 2019, the Company entered into a consulting agreement with Bellco Capital, LLC (Bellco) to provide various executive services to the Company. Arie Belldegrun, M.D., FACS, the Chairman of the Board of Directors, is the Chairman of Bellco. During the three and nine months ended September 30, 2023, the Company incurred expense of $6,300 and $18,900, respectively, for these services. During the three and nine months ended September 30, 2022, the Company incurred expense of $6,300 and $18,900, respectively, for these services.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis


	September 30, 2023
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	24,864	$	—	$	—	$	24,864
Certificates of deposit	975		—		—		975
Commercial paper	—		—		—		—
Corporate bonds	—		9,299		—		9,299
U.S. agency securities	—		6,073		—		6,073
U.S. treasury securities	128,239		—		—		128,239
Total financial assets	$	154,078	$	15,372	$	—	$	169,450


	December 31, 2022
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	49,003	$	—	$	—	$	49,003
Certificates of deposit	490		—		—		490
Commercial paper	—		1,667		—		1,667
Corporate bonds	—		30,657		—		30,657
U.S. agency securities	—		13,000		—		13,000
U.S. treasury securities	138,734		—		—		138,734
Total financial assets	$	188,227	$	45,324	$	—	$	233,551

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Number of Options
Beginning Balance (in shares)	7,454,665
Granted (in shares)	3,200,631
Forfeited (in shares)	(1,471,660)
Exercised (in shares)	(242,379)
Ending Balance (in shares)	8,941,257	7,454,665
Weighted-Average Exercise Price
Beginning Balance (dollars per share)	$ 11.83
Granted (dollars per share)	1.99
Forfeited (dollars per share)	10.94
Exercised (dollars per share)	3.21
Ending Balance (dollars per share)	$ 8.69	$ 11.83
Stock Option Activity, Additional Disclosures
Weighted-Average Remaining Contractual Term	8 years	7 years 8 months 8 days
Aggregate Intrinsic Value	$ 17	$ 54

Leases - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 1,458	$ 1,278	$ 4,013	$ 3,833
Research and development expenses
Lessee, Lease, Description [Line Items]
Operating lease cost	897	767	2,431	2,301
General and administrative
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 561	$ 511	$ 1,582	$ 1,532

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Revenue	$ 917	$ 0	$ 4,002	$ 0
Operating expenses:
Research and development	25,344	23,403	67,675	70,547
General and administrative	9,398	10,135	30,813	32,886
Total operating expenses	34,742	33,538	98,488	103,433
Loss from operations	(33,825)	(33,538)	(94,486)	(103,433)
Other income, net:
Interest and other income, net	2,451	1,282	7,133	2,011
Total other income, net	2,451	1,282	7,133	2,011
Net loss	(31,374)	(32,256)	(87,353)	(101,422)
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities	214	(389)	537	(1,011)
Net comprehensive loss	$ (31,160)	$ (32,645)	$ (86,816)	$ (102,433)
Net loss per share, basic (in dollars per share)	$ (0.54)	$ (0.57)	$ (1.52)	$ (1.81)
Net loss per share, diluted (in dollars per share)	$ (0.54)	$ (0.57)	$ (1.52)	$ (1.81)
Weighted-average shares of common stock, basic (in shares)	58,146,306	56,318,571	57,567,489	56,093,091
Weighted-average shares of common stock, diluted (in shares)	58,146,306	56,318,571	57,567,489	56,093,091