0001741830-24-000067 | 10-Q | XBRL Viewer

COMMITMENTS AND CONTINGENCIES

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Leases

In March 2020, the Company entered into an 11-year lease agreement to move its research and development operations to a 40,514 square-foot facility in Cambridge, Massachusetts (Massachusetts facility). The lease commenced on February 28, 2020 with an initial annual base rent of $4.1 million with rent payments escalating 3.0% annually. 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 and all costs incurred by the Company were reimbursed by the lessor and were included within the total lease liability. In connection with the lease, the Company recognized an operating lease right-of-use asset of $11.5 million and $17.9 million as of September 30, 2024 and December 31, 2023, respectively. The Company recognized an aggregate lease liability of $23.8 million and $25.6 million as of September 30, 2024 and December 31, 2023, respectively. The remaining lease term is 6 years and 5 months, and the estimated incremental borrowing rate is 8.50%.

In February 2021, the Company entered into a lease agreement for its office space in San Mateo, California (California facility) totaling 17,340 square-feet. The initial annual base rent for the space was $1.2 million, and such amount increases by 3% annually on each anniversary of the premises commencement date. In connection with the lease, 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 $0.8 million and $1.7 million as of September 30, 2024 and December 31, 2023, respectively. The Company recognized an aggregate lease liability of $2.0 million and $2.7 million as of September 30, 2024 and December 31, 2023, respectively. The remaining lease term is 1 year 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 condensed balance sheets as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Assets:
Operating lease assets	$	12,269	$	19,657
Liabilities:
Current portion of operating lease liabilities	$	3,259	$	2,893
Noncurrent operating lease liabilities	22,539		25,379
Total operating lease liabilities	$	25,798	$	28,272

The following table summarizes the effect of operating lease costs in the Company’s condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2024 and 2023 (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	727	$	897	$	2,343	$	2,431
General and administrative	421		561		1,450		1,582
Total operating lease cost	$	1,148	$	1,458	$	3,793	$	4,013

Under the lease agreements, the Company made cash payments of $1.9 million and $4.4 million during the three and nine months ended September 30, 2024, respectively. 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 undiscounted future non-cancellable lease payments under the Company's operating leases as of September 30, 2024 for the next five years and thereafter is expected to be as follows (in thousands):


	Amount
Remaining three months of 2024	$	984
2025	5,921
2026	5,405
2027	4,874
2028	5,020
Thereafter	11,404
Total undiscounted lease payments	33,608
Less: Present value adjustment	(7,810)
Present value of operating lease liabilities	$	25,798

Amended Tempus Research and Development 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 AI, Inc. (formerly known as Tempus Labs, Inc., and referred to herein as Tempus), pursuant to which Tempus agreed to provide the Company with research and development services for a period of four years, with the option to decline to have the term extend into the fourth year of the agreement. 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 istisociclib (KB-0742) and KB-9558.

In consideration for access to the services throughout the term of the Amended Tempus Agreement, the Company agreed to pay an annual minimum commitment of $1.5 million in year one, $2.5 million in year two, and $3.0 million in year three. The Company declined to extend the term of the Amended Tempus Agreement into year four. Payments are made in quarterly installments. The annual minimum commitment is nonrefundable and is invoiced quarterly in advance due within 30 days. As of September 30, 2024, the Company had no remaining non-cancellable purchase commitments under this agreement.

Tempus provides detailed reporting monthly which serves as the unit of account for calculating expense for actual services utilized for the analytical services, data licensing, and organoid services. As of September 30, 2024 and December 31, 2023 the prepaid expenses relating to Tempus were $0.2 million and $0.7 million, respectively. The prepaid expenses are assessed on a periodic basis to determine whether it is probable that services will be provided under the agreement. If the Company does not expect that services will be rendered, the prepaid expense is immediately recognized.

The Company is required to make milestone payments upon successful achievement of certain regulatory milestones for istisociclib (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, 2024 and December 31, 2023, the Company determined that achievement of the milestones is not probable, therefore, no corresponding liability has been recorded.

Gilead 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. The

Company is also committed to pay royalties ranging from high-single digits to the mid-teens on annual worldwide net sales of any SYK inhibitor compounds. The Company is 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 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.

COMMITMENTS AND CONTINGENCIES (Tables)

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Schedule of Assets and Liabilities, Operating Leases, Lessee

The following table summarizes the presentation of the Company’s operating leases in its condensed balance sheets as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Assets:
Operating lease assets	$	12,269	$	19,657
Liabilities:
Current portion of operating lease liabilities	$	3,259	$	2,893
Noncurrent operating lease liabilities	22,539		25,379
Total operating lease liabilities	$	25,798	$	28,272

Schedule of Lease Costs


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	727	$	897	$	2,343	$	2,431
General and administrative	421		561		1,450		1,582
Total operating lease cost	$	1,148	$	1,458	$	3,793	$	4,013

Schedule of Maturities on Lease Liabilities


	Amount
Remaining three months of 2024	$	984
2025	5,921
2026	5,405
2027	4,874
2028	5,020
Thereafter	11,404
Total undiscounted lease payments	33,608
Less: Present value adjustment	(7,810)
Present value of operating lease liabilities	$	25,798

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net loss	$ (14,108)	$ (31,374)	$ (60,266)	$ (87,353)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense, excluding restructuring			7,560	19,809
Depreciation	400	500	1,307	1,658
Net amortization (accretion) on available-for-sale securities			(2,435)	(4,103)
Change in accrued interest on available-for-sale securities			127	363
Non-cash lease expense			1,976	1,982
Non-cash impairment of long-lived assets and restructuring			11,758	2,916
Changes in operating assets and liabilities:
Prepaid expenses and other current assets			2,726	1,266
Other noncurrent assets			0	197
Accounts payable			400	(945)
Accrued expenses			(5,701)	(3,798)
Right-of-use operating assets and lease liabilities, net			(2,475)	(1,549)
Deferred revenue			(7,577)	15,999
Net cash used in operating activities			(52,600)	(53,558)
Cash flows from investing activities:
Purchase of property and equipment			0	(648)
Purchase of available-for-sale marketable securities			(78,776)	(170,816)
Maturities of marketable securities			141,851	206,272
Net cash provided by investing activities			63,075	34,808
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options			1	28
Proceeds from issuance of common stock under the employee stock purchase plan			162	348
Net cash provided by financing activities			163	376
Net increase (decrease) in cash and cash equivalents			10,638	(18,374)
Cash, cash equivalents and restricted cash at beginning of period			66,352	77,999
Cash, cash equivalents and restricted cash at end of period	76,990	59,625	76,990	59,625
Supplemental disclosures of non-cash activities:
Cash and cash equivalents at end of period	74,964	57,599	74,964	57,599
Restricted cash at end of period	2,026	2,026	2,026	2,026
Cash, cash equivalents and restricted cash at end of period	$ 76,990	$ 59,625	$ 76,990	$ 59,625

FAIR VALUE MEASUREMENTS (Tables)

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

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

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, 2024 and December 31, 2023 were as follows (in thousands):


	September 30, 2024
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	70,679	$	—	$	—	$	70,679

Corporate bonds	—		9,208		—		9,208
U.S. treasury securities	40,685		—		—		40,685
Total financial assets	$	111,364	$	9,208	$	—	$	120,572


	December 31, 2023
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	36,009	$	—	$	—	$	36,009
Certificates of deposit	733		—		—		733
Corporate bonds	—		3,662		—		3,662
U.S. treasury securities	126,366		—		—		126,366
Total financial assets	$	163,108	$	3,662	$	—	$	166,770

BALANCE SHEET COMPONENTS- Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
BALANCE SHEET COMPONENTS- Narrative (Details) - USD ($)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation	$ 400,000	$ 500,000	$ 1,307,000	$ 1,658,000
Non-cash impairment charge, related leasehold improvements	$ 0	$ 0	$ 1,700,000	$ 600,000

NET LOSS PER SHARE

9 Months Ended

Sep. 30, 2024

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, 2024 and 2023 (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Net loss	$	(14,108)	$	(31,374)	$	(60,266)	$	(87,353)
Weighted-average common stock outstanding, basic and diluted	60,312		58,146		59,979		57,567
Net loss per share, basic and diluted	$	(0.23)	$	(0.54)	$	(1.00)	$	(1.52)

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 anti-dilutive. These are as follows (in thousands):


	September 30, 2024	September 30, 2023
Stock options to purchase common stock	9,069	8,843
Restricted stock units subject to future vesting	1,458	2,504
Expected shares to be purchased under Employee Stock Purchase Plan	698	1,502
Early exercised stock options subject to future vesting	—	98
Restricted stock awards subject to future vesting	—	29

Total	11,225	12,976

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 9, “Commitment and Contingencies” for further details. Because the necessary conditions for issuance of the shares had not been met as of September 30, 2024, the Company excluded these shares from the table above.

COMMITMENTS AND CONTINGENCIES - Schedule of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 1,148	$ 1,458	$ 3,793	$ 4,013
Research and development
Lessee, Lease, Description [Line Items]
Operating lease cost	727	897	2,343	2,431
General and administrative
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 421	$ 561	$ 1,450	$ 1,582

COLLABORATION AND LICENSE AGREEMENT	9 Months Ended
COLLABORATION AND LICENSE AGREEMENT	Sep. 30, 2024
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 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 $177.0 million for the first development candidate per Hit Program, and is eligible to receive net sales milestones of up to $100.0 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 obligations to perform research and development services are satisfied over time, and therefore, the related revenue will be recognized as services are provided. Using the cost-based input model related to the research and development activities associated with the identified performance obligations, the Company recognized $2.4 million and $7.6 million in revenue during the three and nine months ended September 30, 2024, respectively. The Company recognized $0.9 million and $4.0 million in revenue during the three and nine months ended September 30, 2023, respectively. The remaining $6.1 million of the upfront payment is included in short and long-term deferred revenue as of September 30, 2024 and will be recognized as the performance obligations are satisfied.

INVESTMENTS - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Cash equivalents	$ 70,679	$ 56,110
Short-term investments	49,893	108,671
Long-term investments	0	1,989
Total cash equivalents and investments	$ 120,572	$ 166,770

NATURE OF OPERATIONS AND BASIS OF PRESENTATION (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments \| segment	1
Reclassification from research and development to impairment of long-lived assets and restructuring		$ 1,900
Reclassification from general and administrative to impairment of long-lived assets and restructuring		$ 1,000
Net losses	$ 569,127		$ 508,861

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

FAIR VALUE MEASUREMENTS

9 Months Ended

Sep. 30, 2024

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, Certificates of deposit and U.S. treasury securities 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.


	September 30, 2024
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	70,679	$	—	$	—	$	70,679

Corporate bonds	—		9,208		—		9,208
U.S. treasury securities	40,685		—		—		40,685
Total financial assets	$	111,364	$	9,208	$	—	$	120,572


	December 31, 2023
	Level 1		Level 2		Level 3		Fair Value
Financial Assets:
Money market funds	$	36,009	$	—	$	—	$	36,009
Certificates of deposit	733		—		—		733
Corporate bonds	—		3,662		—		3,662
U.S. treasury securities	126,366		—		—		126,366
Total financial assets	$	163,108	$	3,662	$	—	$	166,770

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.

- 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

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+ Details

STOCK-BASED COMPENSATION - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
	Oct. 31, 2020	Sep. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future tax benefit			$ 0	$ 0
Weighted-average grant-date fair value, options granted (in dollars per share)			$ 0.74
Stock options, unrecognized cost		$ 5,400,000	$ 5,400,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options recognized, weighted average period (in years)			2 years 5 months 1 day
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options recognized, weighted average period (in years)			1 year 11 months 1 day
Unrecognized stock based compensation		$ 1,600,000	$ 1,600,000
2020 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for future issuance (in shares)		6,339,045	6,339,045
The ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan (in shares)		0	159,050
The ESPP \| 2020 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for future issuance (in shares)		2,031,609	2,031,609
Number of shares that may have been issued (in shares)	688,000
Number of shares that may be issued, increase percentage (as a percent)	1.00%
Number of shares that may be issued, increase (in shares)	1,376,000

BALANCE SHEET COMPONENTS - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 2,247	$ 3,904
External research and development	2,310	5,821
Accrued outside services	980	807
Accrued taxes	0	133
Other accrued expenses	54	266
Other current liabilities	94	404
Total accrued expenses and other liabilities	$ 5,685	$ 11,335

COMMITMENTS AND CONTINGENCIES - Schedule of Maturities on Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Remaining three months of 2024	$ 984
2025	5,921
2026	5,405
2027	4,874
2028	5,020
Thereafter	11,404
Total undiscounted lease payments	33,608
Less: Present value adjustment	(7,810)
Present value of operating lease liabilities	$ 25,798	$ 28,272

FAIR VALUE MEASUREMENTS (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 120,572	$ 166,770
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value		733
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	9,208	3,662
U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	40,685	126,366
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	70,679	36,009
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	111,364	163,108
Level 1 \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value		733
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. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	40,685	126,366
Level 1 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	70,679	36,009
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	9,208	3,662
Level 2 \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value		0
Level 2 \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	9,208	3,662
Level 2 \| U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	0	0
Level 2 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Level 3 \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value		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. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	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

RESTRUCTURINGS	9 Months Ended
RESTRUCTURINGS	Sep. 30, 2024
Restructuring and Related Activities [Abstract]
RESTRUCTURINGS	RESTRUCTURINGS In early 2024, the Company announced corporate restructuring plans designed to optimize its resource allocation and contain costs. In connection with the restructuring plans, the Company recorded the following costs in restructuring charges: 1) one-time employee termination benefits such as severance and related benefit costs and 2) stock-based compensation expense resulting from the acceleration in full of outstanding unvested stock options and stock awards for certain employees at the separation date. February 2024 Restructuring On January 24, 2024, the Company and three executive officers: the Chief Medical Officer and Executive Vice President, Clinical Development; the Chief Operating Officer and General Counsel; and the Chief Scientific Officer (the “Officers") mutually agreed to the termination of employment effective February 16, 2024 (the “Separation Date”). The separation agreements signed with the Officers outlined the terms of severance and contemplate the engagement of each as a consultant to the Company through December 31, 2024. Total costs of $5.5 million were recorded in the first quarter of 2024, including non-cash stock-based compensation of $4.4 million resulting from the acceleration in full of outstanding unvested stock options and stock awards at the Separation Date for the Officers. March 2024 Restructuring On March 5, 2024, the Company approved an approximate 21% reduction in its workforce as part of a strategic resource allocation and cost containment plan. The workforce reduction was completed on March 7, 2024. Costs of $0.6 million were recorded in the first quarter of 2024 related to this restructuring. During the three months ended September 30, 2024, the Company did not incur any material restructuring costs.

INVESTMENTS - Contractual Maturity (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Investments, Debt and Equity Securities [Abstract]
Due in 1 year or less	$ 49,893
Due in 1 to 2 years	0
Total	$ 49,893

NET LOSS PER SHARE - Schedule of Net Loss Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Net loss	$ (14,108)	$ (16,200)	$ (29,958)	$ (31,374)	$ (29,741)	$ (26,238)	$ (60,266)	$ (87,353)
Weighted-average common stock outstanding, basic (in shares)	60,311,599			58,146,306			59,978,572	57,567,489
Weighted-average common stock outstanding, diluted (in shares)	60,311,599			58,146,306			59,978,572	57,567,489
Net loss per share, basic (in dollars per share)	$ (0.23)			$ (0.54)			$ (1.00)	$ (1.52)
Net loss per share, diluted (in dollars per share)	$ (0.23)			$ (0.54)			$ (1.00)	$ (1.52)

- Definition

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

+ References

+ 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

+ Details

- Definition

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

+ References

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+ Details

INVESTMENTS (Tables)

9 Months Ended

Sep. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Schedule of 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, 2024 and December 31, 2023 were as follows (in thousands):


	September 30, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	70,679	$	—	$	—	$	70,679

Corporate bonds	9,208		—		—		9,208
U.S. treasury securities	40,661		24		—		40,685
Total cash equivalents and investments	$	120,548	$	24	$	—	$	120,572


	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	36,009	$	—	$	—	$	36,009
Certificates of deposit	735		—		(2)		733
Corporate bonds	3,662		—		—		3,662
U.S. treasury securities	126,345		74		(53)		126,366
Total cash equivalents and investments	$	166,751	$	74	$	(55)	$	166,770

These available-for-sale securities, including money market funds, were classified on the Company’s condensed balance sheets as of September 30, 2024 and December 31, 2023 as (in thousands):


	Fair Value
	September 30, 2024		December 31, 2023
Cash equivalents	$	70,679	$	56,110
Short-term investments	49,893		108,671
Long-term investments	—		1,989
Total cash equivalents and investments	$	120,572	$	166,770

The fair values of available-for-sale securities, excluding money market funds, by contractual maturity as of September 30, 2024 were as follows (in thousands):


	September 30, 2024
Due in 1 year or less	$	49,893
Due in 1 to 2 years	—

Total	$	49,893

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Stockholders’ equity:
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
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)	60,336,000	58,946,000
Common stock, shares outstanding (in shares)	60,336,000	58,946,000

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Revenue	$ 2,370	$ 917	$ 7,578	$ 4,002
Operating expenses:
Research and development	12,268	25,344	40,255	65,811
General and administrative	5,818	9,398	19,692	29,761
Impairment of long-lived assets and restructuring	0	0	13,364	2,916
Total operating expenses	18,086	34,742	73,311	98,488
Loss from operations	(15,716)	(33,825)	(65,733)	(94,486)
Other income (expense), net:
Interest income and other expense, net	1,608	2,451	5,467	7,133
Total other income (expense), net	1,608	2,451	5,467	7,133
Net loss	(14,108)	(31,374)	(60,266)	(87,353)
Other comprehensive loss:
Net unrealized gain (loss) on available-for-sale securities	60	214	5	537
Comprehensive loss	$ (14,048)	$ (31,160)	$ (60,261)	$ (86,816)
Net loss per share, basic (in dollars per share)	$ (0.23)	$ (0.54)	$ (1.00)	$ (1.52)
Net loss per share, diluted (in dollars per share)	$ (0.23)	$ (0.54)	$ (1.00)	$ (1.52)
Weighted-average shares of common stock, basic (in shares)	60,311,599	58,146,306	59,978,572	57,567,489
Weighted-average shares of common stock, diluted (in shares)	60,311,599	58,146,306	59,978,572	57,567,489

STOCK-BASED COMPENSATION - Schedule of Total Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,030	$ 6,296	$ 11,939	$ 19,809
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	769	3,237	2,704	9,472
General and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,261	3,059	4,856	10,337
Restructuring costs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 0	$ 0	$ 4,379	$ 0

- 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

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+ Details

INVESTMENTS - Narrative (Details) - USD ($)	9 Months Ended	12 Months Ended
INVESTMENTS - Narrative (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Realized losses on available-for-sale securities	$ 0	$ 0

IMPAIRMENT OF LONG-LIVED ASSETS (Details)	3 Months Ended		9 Months Ended
IMPAIRMENT OF LONG-LIVED ASSETS (Details)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Non-cash impairment of long-lived assets and restructuring	$ 0		$ 7,100,000	$ 2,900,000
Impairment of long-lived assets, right-of-use asset			5,400,000	2,300,000
Impairment of long-lived assets, related leasehold improvements	$ 0	$ 0	$ 1,700,000	$ 600,000
Measurement Input, Expected Sublease Income
Impaired Long-Lived Assets Held and Used [Line Items]
Sublease income, measurement input	22,000,000.0		22,000,000.0
Measurement Input, Discount Rate
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived asset, measurement input	0.100		0.100

RELATED PARTIES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
RELATED PARTIES (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Two River Consulting, LLC
Related Party Transaction [Line Items]
Expenses from transaction with related party, less than	$ 0.1	$ 0.1	$ 0.3	$ 0.1
Bellco Capital, LLC
Related Party Transaction [Line Items]
Expenses from transaction with related party, less than	$ 0.1	$ 0.1	$ 0.1	$ 0.1

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2024	Nov. 08, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
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		60,340,918
Entity Central Index Key	0001741830
Current Fiscal Year End Date	--12-31
Document Fiscal Year End	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false

SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	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.
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 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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (FASB) issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances the disclosures required for income taxes in the Company’s annual financial statements. ASU 2023-09 is effective for the Company in its annual reporting for fiscal 2025 on a prospective basis. Early adoption and retrospective reporting are permitted. The Company does not plan to adopt this standard early. The adoption of this standard is not expected to have a material impact on the Company’s financial statements. In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which requires all public entities, including public entities with a single reportable segment, to provide in interim and annual periods one or more measures of segment profit or loss used by the chief operating decision maker to allocate resources and assess performance. Additionally, the standard requires disclosures of significant segment expenses and other segment items as well as incremental qualitative disclosures. The guidance in this update is effective for fiscal years beginning after December 15, 2023, and interim periods after December 15, 2024. The adoption of this standard is not expected to have a material impact on the Company’s financial statements. There have been no other recent accounting pronouncements during the three and nine months ended September 30, 2024 that are of significance to the Company.

INCOME TAXES	9 Months Ended
INCOME TAXES	Sep. 30, 2024
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, 2024 and 2023. 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, 2024 and 2023. The Company has not identified any new uncertain tax positions as of September 30, 2024. 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 tax.

+ References

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

BALANCE SHEET COMPONENTS (Tables)

9 Months Ended

Sep. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Property, Plant and Equipment

Property and equipment, net consisted of the following as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Lab equipment	$	8,019	$	8,055
Leasehold improvements	6,997		8,703
Furniture, fixtures and computer equipment	784		784

Total property and equipment	15,800		17,542
Less: Accumulated depreciation	(8,567)		(7,290)
Total property and equipment, net	$	7,233	$	10,252

Schedule of Accrued Expenses and Other Liabilities

Accrued expenses consisted of the following as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Accrued compensation	$	2,247	$	3,904
External research and development	2,310		5,821
Accrued outside services	980		807
Accrued taxes	—		133
Other accrued expenses	54		266
Other current liabilities	94		404
Total accrued expenses and other liabilities	$	5,685	$	11,335

NATURE OF OPERATIONS AND BASIS OF PRESENTATION	9 Months Ended
NATURE OF OPERATIONS AND BASIS OF PRESENTATION	Sep. 30, 2024
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 a clinical stage biopharmaceutical company dedicated to developing small molecule therapeutics that address deregulated transcription, a hallmark of cancer and autoimmune disease. The Company operates in one business segment which is 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. Reclassifications As a result of material impairment charges recorded during the nine months ended September 30, 2024, and to conform to the current year presentation in the condensed statements of operations and comprehensive loss, the Company has reclassified amounts originally recorded during the nine months ended September 30, 2023. The Company reclassified $1.9 million from research and development and $1.0 million from general and administration to impairment of long-lived assets and restructuring for the nine months ended September 30, 2023. Unaudited Interim Financial Information The accompanying condensed balance sheet as of September 30, 2024, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2024 and 2023, the condensed statements of stockholders’ equity as of September 30, 2024 and September 30, 2023, the condensed statements of cash flows for the nine months ended September 30, 2024 and 2023 (collectively referred to as the “condensed financial statements”), and the financial data and other financial information disclosed in the notes to the condensed financial statements are unaudited. The unaudited 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, 2024 and the results of its operations for the three and nine months ended September 30, 2024 and 2023. The results for the three and nine months ended September 30, 2024 are not necessarily indicative of results to be expected for the full year ending December 31, 2024, 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, 2023, filed with the SEC on March 21, 2024 (Annual Report). Need for Additional Capital The Company has incurred net losses since its inception of $569.1 million as of September 30, 2024. The Company expects that its cash, cash equivalents and investments as of September 30, 2024 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 other developmental research and development subsequent to the discontinuation of the development of istisociclib, and on the exploration of strategic alternatives to maximize stockholder value that was announced on November 13, 2024. The Company intends and needs 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. Failure to manage discretionary spending, raise additional financing or execute on a strategic alternative, may adversely impact our ability to achieve our intended business objectives. 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, including such as those announced on November 13, 2024, which includes the exploration of strategic alternatives to maximize stockholder value and implementation of significant expense reduction 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.

NET LOSS PER SHARE - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	11,225	12,976
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)	9,069	8,843
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)	1,458	2,504
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)	698	1,502
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)	0	98
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)	0	29

STOCK-BASED COMPENSATION - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Number of Options
Beginning balance (in shares)	8,253
Granted (in shares)	2,485
Forfeited (in shares)	(1,613)
Exercised (in shares)	(56)
Ending balance (in shares)	9,069	8,253
Weighted-Average Exercise Price
Beginning balance (dollars per share)	$ 8.92
Granted (dollars per share)	1.03
Forfeited (dollars per share)	8.90
Exercised (dollars per share)	3.74
Ending balance (dollars per share)	$ 6.80	$ 8.92
Stock Option Activity, Additional Disclosures
Weighted-Average Remaining Contractual Term	7 years 5 months 12 days	6 years 8 months 26 days
Aggregate Intrinsic Value	$ 85	$ 19

RESTRUCTURINGS (Details) $ in Millions	3 Months Ended
RESTRUCTURINGS (Details) $ in Millions	Mar. 31, 2024 USD ($)	Mar. 05, 2024	Jan. 24, 2024 officer
February 2024 Restructuring
Restructuring Cost and Reserve [Line Items]
Number of executive officers, terminated \| officer			3
Restructuring costs	$ 5.5
February 2024 Restructuring \| Stock Based Compensation
Restructuring Cost and Reserve [Line Items]
Restructuring costs	4.4
March 2024 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs	0.0
Reduction of workforce (as a percent)		21.00%
March 2024 Restructuring \| Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0.6

- 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 + Details

BALANCE SHEET COMPONENTS - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property and equipment
Property, plant and equipment, gross	$ 15,800	$ 17,542
Less: Accumulated depreciation	(8,567)	(7,290)
Total property and equipment, net	7,233	10,252
Lab equipment
Property and equipment
Property, plant and equipment, gross	8,019	8,055
Leasehold improvements
Property and equipment
Property, plant and equipment, gross	6,997	8,703
Furniture, fixtures and computer equipment
Property and equipment
Property, plant and equipment, gross	$ 784	$ 784

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 74,964	$ 64,326
Short-term investments	49,893	108,671
Prepaid expenses and other current assets	3,062	5,781
Total current assets	127,919	178,778
Long-term investments	0	1,989
Property and equipment, net	7,233	10,252
Operating lease right-of-use assets	12,269	19,657
Restricted cash	2,026	2,026
Other noncurrent assets	577	577
Total assets	150,024	213,279
Current liabilities:
Accounts payable	1,279	883
Accrued expenses and other liabilities	5,685	11,335
Current portion of operating lease liabilities	3,259	2,893
Current portion of deferred revenue	5,159	9,584
Total current liabilities	15,382	24,695
Noncurrent operating lease liabilities	22,539	25,379
Noncurrent deferred revenue	975	4,127
Total liabilities	38,896	54,201
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000 shares authorized; no shares issued and outstanding.
Common stock, $0.001 par value, 200,000 shares authorized as of September 30, 2024 and December 31, 2023; 60,336 and 58,946 shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively.	60	59
Additional paid-in capital	680,171	667,861
Accumulated deficit	(569,127)	(508,861)
Accumulated other comprehensive income	24	19
Total stockholders' equity	111,128	159,078
Total liabilities and stockholders’ equity	$ 150,024	$ 213,279

INCOME TAXES (Details) - USD ($)	3 Months Ended		9 Months Ended
INCOME TAXES (Details) - USD ($)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 5: 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 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.7)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 7: 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 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-10

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(9))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Subparagraph (a)
-SubTopic 20
-Topic 740
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482659/740-20-45-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h))
-SubTopic 10
-Topic 235
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

COLLABORATION AND LICENSE AGREEMENT (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 06, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue		$ 2,370	$ 917	$ 7,578	$ 4,002
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration and license agreement, termination notice period, prior written notice (in days)	60 days
Collaboration and license agreement, termination notice period, uncured material breach (in days)	90 days
Collaboration and license agreement, termination notice period, uncured material breach, nonpayment (in days)	45 days
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected timing of satisfaction, extension period (in months)	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 (in months)	24 months
Genentech, Inc. \| License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment	$ 20,000	$ 6,100		$ 6,100
Maximum aggregate milestone payments	177,000
Maximum aggregate milestone payments from net sales	$ 100,000

STOCK-BASED COMPENSATION - Schedule of Nonvested Share Activity (Details) - Restricted Stock Awards And Restricted Stock Units - $ / shares shares in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Number of Restricted Stock
Unvested beginning balance (in shares)	1,657
Granted (in shares)	1,431
Vested and converted to shares (in shares)	(1,175)
Forfeited (in shares)	(455)
Unvested ending balance (in shares)	1,458	1,657
Weighted-Average Grant Date Fair Value
Unvested beginning balance (in dollars per share)	$ 3.76
Granted (in dollars per share)	1.03
Vested and converted to shares (in dollars per share)	3.88
Forfeited (in dollars per share)	1.82
Unvested ending balance (in dollars per share)	$ 1.60	$ 3.76
Restricted Stock Awards, Additional Disclosures
Weighted-Average Remaining Vesting Life	1 year 2 months 15 days	1 year 11 months 1 day

IMPAIRMENT OF LONG-LIVED ASSETS	9 Months Ended
IMPAIRMENT OF LONG-LIVED ASSETS	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
IMPAIRMENT OF LONG-LIVED ASSETS	IMPAIRMENT OF LONG-LIVED ASSETS The Company at each reporting period reviews for impairment indicators for its long-lived assets. The sustained decline in the Company’s market capitalization as compared to the Company’s net asset value remained as the indicator of impairment, in addition to the Company’s shift in strategy to consider subleasing both the Massachusetts and California facilities. 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. 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 asset group, the Company utilized the discounted cash flow method of the income approach. During the nine months ended September 30, 2024, the Company recognized non-cash impairment charges of $7.1 million. The Company did not record any non-cash impairment charges during the three months ended September 30, 2024. Impairment charges of $7.1 million for the nine months ended September 30, 2024 included $5.4 million for right-of-use assets and $1.7 million for leasehold improvements. 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. The Company did not record any non-cash impairment charges during the three months ended September 30, 2023. The Company applied a discounted cash flow method to estimate the fair value of the asset group, which represents Level 3 non-recurring fair value measurements. The estimated fair value of the asset group was determined by discounting the estimated sublease income using market participant assumptions, including but not limited to, expected sublease rental income of $22.0 million, and an annual discount rate of 10.0%, which the Company evaluated based on current real estate trends and market conditions. The Company’s estimates and assumptions used to determine the estimated fair value of the asset group is subject to risks, uncertainties, and changes in circumstances that may result in adjustments and material changes to the estimated fair values in future periods.

NET LOSS PER SHARE (Tables)

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Schedule of Net Loss Per Share, Basic and Diluted

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, 2024 and 2023 (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Net loss	$	(14,108)	$	(31,374)	$	(60,266)	$	(87,353)
Weighted-average common stock outstanding, basic and diluted	60,312		58,146		59,979		57,567
Net loss per share, basic and diluted	$	(0.23)	$	(0.54)	$	(1.00)	$	(1.52)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share


	September 30, 2024	September 30, 2023
Stock options to purchase common stock	9,069	8,843
Restricted stock units subject to future vesting	1,458	2,504
Expected shares to be purchased under Employee Stock Purchase Plan	698	1,502
Early exercised stock options subject to future vesting	—	98
Restricted stock awards subject to future vesting	—	29

Total	11,225	12,976

COMMITMENTS AND CONTINGENCIES - Narrative (Details)	1 Months Ended			3 Months Ended		9 Months Ended
COMMITMENTS AND CONTINGENCIES - Narrative (Details)	Apr. 30, 2023 USD ($) service	Feb. 28, 2021 USD ($) ft²	Mar. 31, 2020 USD ($) ft²	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Schedule Of Asset Acquisition [Line Items]
Operating lease right-of-use assets				$ 12,269,000		$ 12,269,000		$ 19,657,000
Present value of operating lease liabilities				25,798,000		25,798,000		28,272,000
Lease payments				1,900,000	$ 1,300,000	4,400,000	$ 3,700,000
Prepaid expenses and other current assets				3,062,000		3,062,000		5,781,000
Sales milestone payable				0		0		0
Tempus Labs, Inc.
Schedule Of Asset Acquisition [Line Items]
Purchase obligation, quarterly payment term (in days)	30 days
Prepaid expenses and other current assets				200,000		200,000		700,000
Tempus Labs, Inc. \| Research And Development Services
Schedule Of Asset Acquisition [Line Items]
Services contract term (in years)	4 years
Number of primary services \| service	3
Annual minimum commitment payment in year one	$ 1,500,000
Annual minimum commitment payment in year two	2,500,000
Annual minimum commitment payment in year three	3,000,000.0
Purchase obligation				0		0
Sales milestone payment	$ 22,400,000
Sales milestone payment in shares of common stock, percent threshold (as a percent)	50.00%
Cambridge, Massachusetts
Schedule Of Asset Acquisition [Line Items]
Lease term (in years)			11 years
Facility size \| ft²			40,514
Initial annual base rent			$ 4,100,000
Escalating rent payments (as a percent)			3.00%
Letter of credit			$ 2,000,000.0
Tenant improvement allowances			$ 3,700,000
Operating lease right-of-use assets				11,500,000		11,500,000		17,900,000
Present value of operating lease liabilities				$ 23,800,000		$ 23,800,000		25,600,000
Remaining lease term (in years)				6 years 5 months		6 years 5 months
Incremental borrowing rate (as a percent)				8.50%		8.50%
San Mateo, California. February 2021 Lease Agreement
Schedule Of Asset Acquisition [Line Items]
Facility size \| ft²		17,340
Initial annual base rent		$ 1,200,000
Escalating rent payments (as a percent)		3.00%
Operating lease right-of-use assets				$ 800,000		$ 800,000		1,700,000
Present value of operating lease liabilities				$ 2,000,000.0		$ 2,000,000.0		$ 2,700,000
Remaining lease term (in years)				1 year 9 months		1 year 9 months
Incremental borrowing rate (as a percent)				11.18%		11.18%
Security deposit		$ 59,000

COMMITMENTS AND CONTINGENCIES - Schedule of Assets and Liabilities, Operating Leases, Lessee (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets:
Operating lease assets	$ 12,269	$ 19,657
Liabilities:
Current portion of operating lease liabilities	3,259	2,893
Noncurrent operating lease liabilities	22,539	25,379
Total operating lease liabilities	$ 25,798	$ 28,272

SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS	SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS 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 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. Significant Accounting Policies There have been no significant changes to the accounting policies during the three and nine months ended September 30, 2024, as compared to the significant accounting policies described in Item 8 Financial Statements and Supplementary Data, Note 2 of the “Notes to Financial Statements” of the Company’s audited financial statements included in its Annual Report for the fiscal year ended December 31, 2023. Recent Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (FASB) issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances the disclosures required for income taxes in the Company’s annual financial statements. ASU 2023-09 is effective for the Company in its annual reporting for fiscal 2025 on a prospective basis. Early adoption and retrospective reporting are permitted. The Company does not plan to adopt this standard early. The adoption of this standard is not expected to have a material impact on the Company’s financial statements. In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which requires all public entities, including public entities with a single reportable segment, to provide in interim and annual periods one or more measures of segment profit or loss used by the chief operating decision maker to allocate resources and assess performance. Additionally, the standard requires disclosures of significant segment expenses and other segment items as well as incremental qualitative disclosures. The guidance in this update is effective for fiscal years beginning after December 15, 2023, and interim periods after December 15, 2024. The adoption of this standard is not expected to have a material impact on the Company’s financial statements. There have been no other recent accounting pronouncements during the three and nine months ended September 30, 2024 that are of significance to the Company.

STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Option Activity

Stock option activity under the 2020 Plan as of September 30, 2024 is summarized as follows:


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
	(in thousands)			(in years)	(in thousands)
Balance, December 31, 2023	8,253	$	8.92	6.74	$	19
Granted	2,485	1.03
Forfeited	(1,613)	8.90
Exercised	(56)	3.74
Balance, September 30, 2024	9,069	$	6.80	7.45	$	85

Schedule of Nonvested Share Activity

Restricted stock awards and restricted stock units as of September 30, 2024 are summarized as follows:


	Number of Restricted Stock	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Vesting Life
	(in thousands)			(in years)
Unvested, December 31, 2023	1,657	$	3.76	1.92
Granted	1,431	1.03
Vested and converted to shares	(1,175)	3.88
Forfeited	(455)	1.82
Unvested, September 30, 2024	1,458	$	1.60	1.21

Schedule of Total Stock-based Compensation

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, 2024 and 2023 is as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development expense	$	769	$	3,237	$	2,704	$	9,472
General and administrative expense	1,261		3,059		4,856		10,337
Restructuring costs	$	—	$	—	4,379		—
Total stock-based compensation expense	$	2,030	$	6,296	$	11,939	$	19,809

RELATED PARTIES	9 Months Ended
RELATED PARTIES	Sep. 30, 2024
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. During the three and nine months ended September 30, 2024, the Company incurred expenses of less than $0.1 million and $0.3 million, respectively, for these services. During the three and nine months ended September 30, 2023, the Company incurred expenses of less than $0.1 million, 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. The Company incurred expenses of less than $0.1 million for both the three and nine months ended September 30, 2024 and 2023 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/1943274/2147477968/946-235-50-2

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/1943274/2147477968/946-235-50-2

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/1943274/2147479134/946-220-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/1943274/2147479134/946-220-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/1943274/2147479134/946-220-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

INVESTMENTS - Fair Value and Amortized Cost (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Schedule of Held-to-maturity Securities [Line Items]
Money market funds, amortized cost	$ 70,679	$ 56,110
Unrealized Gains	24	74
Unrealized Losses	0	(55)
Fair Value	49,893
Total cash equivalents and investments, amortized cost	120,548	166,751
Total cash equivalents and investments, fair value	120,572	166,770
Certificates of deposit
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		735
Unrealized Gains		0
Unrealized Losses		(2)
Fair Value		733
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	9,208	3,662
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	9,208	3,662
U.S. treasury securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	40,661	126,345
Unrealized Gains	24	74
Unrealized Losses	0	(53)
Fair Value	40,685	126,366
Money market funds
Schedule of Held-to-maturity Securities [Line Items]
Money market funds, amortized cost	$ 70,679	$ 36,009

Condensed Statements of Stockholders’ Equity (Unaudited) - USD ($) shares in Thousands, $ 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, 2022		56,967
Beginning balance at Dec. 31, 2022	$ 244,499	$ 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)		387
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	305		305
Stock-based compensation expense	6,607		6,607
Net unrealized gain (loss) on available-for-sale securities	432			432
Net loss	(26,238)				(26,238)
Common stock, ending balance (in shares) at Mar. 31, 2023		57,354
Ending 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
Beginning balance at Dec. 31, 2022	244,499	$ 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
Ending balance at Sep. 30, 2023	178,620	$ 58	662,358	(255)	(483,541)
Common stock, beginning balance (in shares) at Mar. 31, 2023		57,354
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
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	333	$ 1	332
Stock-based compensation expense	6,906		6,906
Employee stock purchase plan (in shares)		247
Employee stock purchase plan	348		348
Net unrealized gain (loss) on available-for-sale securities	(109)			(109)
Net loss	(29,741)				(29,741)
Common stock, ending balance (in shares) at Jun. 30, 2023		58,122
Ending 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
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	142		142
Stock-based compensation expense	6,296		6,296
Net unrealized gain (loss) on available-for-sale securities	214			214
Net loss	(31,374)				(31,374)
Common stock, ending balance (in shares) at Sep. 30, 2023		58,180
Ending balance at Sep. 30, 2023	$ 178,620	$ 58	662,358	(255)	(483,541)
Common stock, beginning balance (in shares) at Dec. 31, 2023	58,946	58,946
Beginning balance at Dec. 31, 2023	$ 159,078	$ 59	667,861	19	(508,861)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)		1,143
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	210	$ 1	209
Stock-based compensation expense	7,706		7,706
Net unrealized gain (loss) on available-for-sale securities	(68)			(68)
Net loss	(29,958)				(29,958)
Common stock, ending balance (in shares) at Mar. 31, 2024		60,089
Ending balance at Mar. 31, 2024	$ 136,968	$ 60	675,776	(49)	(538,819)
Common stock, beginning balance (in shares) at Dec. 31, 2023	58,946	58,946
Beginning balance at Dec. 31, 2023	$ 159,078	$ 59	667,861	19	(508,861)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net unrealized gain (loss) on available-for-sale securities	5
Net loss	$ (60,266)
Common stock, ending balance (in shares) at Sep. 30, 2024	60,336	60,336
Ending balance at Sep. 30, 2024	$ 111,128	$ 60	680,171	24	(569,127)
Common stock, beginning balance (in shares) at Mar. 31, 2024		60,089
Beginning balance at Mar. 31, 2024	136,968	$ 60	675,776	(49)	(538,819)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)		24
Stock-based compensation expense	2,203		2,203
Employee stock purchase plan (in shares)		159
Employee stock purchase plan	162		162
Net unrealized gain (loss) on available-for-sale securities	13			13
Net loss	(16,200)				(16,200)
Common stock, ending balance (in shares) at Jun. 30, 2024		60,272
Ending balance at Jun. 30, 2024	123,146	$ 60	678,141	(36)	(555,019)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)		64
Stock-based compensation expense	2,030		2,030
Net unrealized gain (loss) on available-for-sale securities	60			60
Net loss	$ (14,108)				(14,108)
Common stock, ending balance (in shares) at Sep. 30, 2024	60,336	60,336
Ending balance at Sep. 30, 2024	$ 111,128	$ 60	$ 680,171	$ 24	$ (569,127)

INVESTMENTS

9 Months Ended

Sep. 30, 2024

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, 2024 and December 31, 2023 were as follows (in thousands):


	September 30, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	70,679	$	—	$	—	$	70,679

Corporate bonds	9,208		—		—		9,208
U.S. treasury securities	40,661		24		—		40,685
Total cash equivalents and investments	$	120,548	$	24	$	—	$	120,572


	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Money market funds	$	36,009	$	—	$	—	$	36,009
Certificates of deposit	735		—		(2)		733
Corporate bonds	3,662		—		—		3,662
U.S. treasury securities	126,345		74		(53)		126,366
Total cash equivalents and investments	$	166,751	$	74	$	(55)	$	166,770

These available-for-sale securities, including money market funds, were classified on the Company’s condensed balance sheets as of September 30, 2024 and December 31, 2023 as (in thousands):


	Fair Value
	September 30, 2024		December 31, 2023
Cash equivalents	$	70,679	$	56,110
Short-term investments	49,893		108,671
Long-term investments	—		1,989
Total cash equivalents and investments	$	120,572	$	166,770

The fair values of available-for-sale securities, excluding money market funds, by contractual maturity as of September 30, 2024 were as follows (in thousands):


	September 30, 2024
Due in 1 year or less	$	49,893
Due in 1 to 2 years	—

Total	$	49,893

As of September 30, 2024 and December 31, 2023, there have been no realized losses on available-for-sale securities for any of the periods presented in the accompanying condensed financial statements. 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.

STOCK-BASED COMPENSATION

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

As of September 30, 2024, there were 6,339,045 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, 2024 is summarized as follows:


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
	(in thousands)			(in years)	(in thousands)
Balance, December 31, 2023	8,253	$	8.92	6.74	$	19
Granted	2,485	1.03
Forfeited	(1,613)	8.90
Exercised	(56)	3.74
Balance, September 30, 2024	9,069	$	6.80	7.45	$	85

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, 2024. There was no future tax benefit related to options exercised, as the Company had accumulated net operating losses as of September 30, 2024 and December 31, 2023.

The weighted-average grant-date fair value per share for stock options granted using the Black–Scholes option pricing model was $0.74 for the nine months ended September 30, 2024.

As of September 30, 2024, there was $5.4 million of unrecognized stock-based compensation related to stock options, respectively, which is expected to be recognized over a weighted-average remaining vesting period of 2.42 years.

Restricted Stock

Restricted stock awards and restricted stock units as of September 30, 2024 are summarized as follows:


	Number of Restricted Stock	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Vesting Life
	(in thousands)			(in years)
Unvested, December 31, 2023	1,657	$	3.76	1.92
Granted	1,431	1.03
Vested and converted to shares	(1,175)	3.88
Forfeited	(455)	1.82
Unvested, September 30, 2024	1,458	$	1.60	1.21

As of September 30, 2024, there was $1.6 million of unrecognized stock-based compensation related to RSUs, which is expected to be recognized over a weighted average remaining vesting period of 1.92.

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 issued 159,050 shares of common stock during the nine months ended September 30, 2024 under the ESPP. There were no shares issued during the three months ended September 30, 2024. The Company has 2,031,609 shares reserved for future issuance as of September 30, 2024.

Stock-Based Compensation Summary


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development expense	$	769	$	3,237	$	2,704	$	9,472
General and administrative expense	1,261		3,059		4,856		10,337
Restructuring costs	$	—	$	—	4,379		—
Total stock-based compensation expense	$	2,030	$	6,296	$	11,939	$	19,809

BALANCE SHEET COMPONENTS

9 Months Ended

Sep. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

BALANCE SHEET COMPONENTS

Property and Equipment, net

Property and equipment, net consisted of the following as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Lab equipment	$	8,019	$	8,055
Leasehold improvements	6,997		8,703
Furniture, fixtures and computer equipment	784		784

Total property and equipment	15,800		17,542
Less: Accumulated depreciation	(8,567)		(7,290)
Total property and equipment, net	$	7,233	$	10,252

Depreciation expense was $0.4 million and $0.5 million for the three months ended September 30, 2024 and 2023, respectively. Depreciation expense was $1.3 million and $1.7 million for the nine months ended September 30, 2024 and 2023, respectively.

During the nine months ended September 30, 2024, the Company recognized a non-cash impairment charge of $1.7 million to leasehold improvements. There were no non-cash impairment charges recorded during the three months ended September 30, 2024.

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. Please refer to Note 7 “Impairment of Long-lived Assets” for further details.

Accrued Expenses and Other Liabilities

Accrued expenses consisted of the following as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Accrued compensation	$	2,247	$	3,904
External research and development	2,310		5,821
Accrued outside services	980		807
Accrued taxes	—		133
Other accrued expenses	54		266
Other current liabilities	94		404
Total accrued expenses and other liabilities	$	5,685	$	11,335