Kronos Bio (KRON) 10-Q 8 Nov 22 2022 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2022	Nov. 02, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
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	Large Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		56,898,374
Entity Central Index Key	0001741830
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	[1]
Current assets:
Cash and cash equivalents	$ 67,481	$ 198,270
Short-term investments	190,774	141,239
Prepaid expenses and other current assets	6,375	8,045
Total current assets	264,630	347,554
Long-term investments	12,086	0
Property and equipment, net	13,538	14,880
Operating lease right-of-use assets	25,276	26,904
Restricted cash	2,026	2,026
Other noncurrent assets	112	112
Total assets	317,668	391,476
Current liabilities:
Accounts payable	1,462	998
Accrued expenses	14,994	9,063
Current portion of operating lease liabilities	2,239	2,109
Current portion of other liabilities	1,410	1,456
Total current liabilities	20,105	13,626
Noncurrent operating lease liabilities	29,526	31,653
Other noncurrent liabilities	350	1,100
Total liabilities	49,981	46,379
Commitments and contingencies (Note 11)
Stockholders’ equity:
Common stock, $0.001 par value, 200,000,000 authorized as of September 30, 2022 and December 31, 2021; 56,439,628 and 55,703,327 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively.	56	56
Preferred stock, $0.001 par value; 10,000,000 authorized; no shares issued and outstanding.
Additional paid-in capital	633,087	608,064
Accumulated deficit	(364,406)	(262,984)
Accumulated other comprehensive income (loss)	(1,050)	(39)
Total stockholders' equity	267,687	345,097
Total liabilities and stockholders’ equity	$ 317,668	$ 391,476
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
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)	56,439,628	55,703,327
Common stock, shares outstanding (in shares)	56,439,628	55,703,327
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

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating expenses:
Research and development	$ 23,403	$ 24,688	$ 70,547	$ 62,084
General and administrative	10,135	8,985	32,886	26,908
Total operating expenses	33,538	33,673	103,433	88,992
Loss from operations	(33,538)	(33,673)	(103,433)	(88,992)
Other income (expense), net:
Interest and other income, net	1,282	70	2,011	248
Total other income (expense), net	1,282	70	2,011	248
Net loss	(32,256)	(33,603)	(101,422)	(88,744)
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities	(389)	1	(1,011)	26
Net comprehensive loss	$ (32,645)	$ (33,602)	$ (102,433)	$ (88,718)
Net loss per share, basic (in dollars per share)	$ (0.57)	$ (0.61)	$ (1.81)	$ (1.63)
Net loss per share, diluted (in dollars per share)	$ (0.57)	$ (0.61)	$ (1.81)	$ (1.63)
Weighted-average shares of common stock, basic (in shares)	56,318,571	54,977,085	56,093,091	54,549,747
Weighted-average shares of common stock, diluted (in shares)	56,318,571	54,977,085	56,093,091	54,549,747

Condensed Statements of Stockho

Condensed Statements of Stockholders’ Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total		Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Common stock, beginning balance (in shares) at Dec. 31, 2020			54,073,901
Beginning balance at Dec. 31, 2020	$ 465,519		$ 54	$ 577,390	$ (19)	$ (111,906)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)			312,062
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	590			590
Stock-based compensation expense	5,238			5,238
Net unrealized gain (loss) on available-for-sale securities	(4)				(4)
Net loss	(26,086)					(26,086)
Common stock, ending balance (in shares) at Mar. 31, 2021			54,385,963
Beginning balance at Mar. 31, 2021	445,257		$ 54	583,218	(23)	(137,992)
Common stock, beginning balance (in shares) at Dec. 31, 2020			54,073,901
Beginning balance at Dec. 31, 2020	465,519		$ 54	577,390	(19)	(111,906)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net unrealized gain (loss) on available-for-sale securities	26
Net loss	(88,744)
Common stock, ending balance (in shares) at Sep. 30, 2021			55,217,844
Beginning balance at Sep. 30, 2021	399,023		$ 55	599,611	7	(200,650)
Common stock, beginning balance (in shares) at Mar. 31, 2021			54,385,963
Beginning balance at Mar. 31, 2021	445,257		$ 54	583,218	(23)	(137,992)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)			322,812
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	627		$ 1	626
Stock-based compensation expense	6,432			6,432
Employee stock purchase plan (in shares)			50,569
Employee stock purchase plan	817			817
Net unrealized gain (loss) on available-for-sale securities	29				29
Net loss	(29,055)					(29,055)
Common stock, ending balance (in shares) at Jun. 30, 2021			54,759,344
Beginning balance at Jun. 30, 2021	424,107		$ 55	591,093	6	(167,047)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)			458,500
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	1,381			1,381
Stock-based compensation expense	7,137			7,137
Net unrealized gain (loss) on available-for-sale securities	1				1
Net loss	(33,603)					(33,603)
Common stock, ending balance (in shares) at Sep. 30, 2021			55,217,844
Beginning balance at Sep. 30, 2021	399,023		$ 55	599,611	7	(200,650)
Common stock, beginning balance (in shares) at Dec. 31, 2021			55,703,327
Beginning balance at Dec. 31, 2021	345,097	[1]	$ 56	608,064	(39)	(262,984)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)			361,182
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	529			529
Stock-based compensation expense	7,788			7,788
Net unrealized gain (loss) on available-for-sale securities	(131)				(131)
Net loss	(36,263)					(36,263)
Common stock, ending balance (in shares) at Mar. 31, 2022			56,064,509
Beginning balance at Mar. 31, 2022	317,020		$ 56	616,381	(170)	(299,247)
Common stock, beginning balance (in shares) at Dec. 31, 2021			55,703,327
Beginning balance at Dec. 31, 2021	345,097	[1]	$ 56	608,064	(39)	(262,984)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net unrealized gain (loss) on available-for-sale securities	(1,011)
Net loss	(101,422)
Common stock, ending balance (in shares) at Sep. 30, 2022			56,439,628
Beginning balance at Sep. 30, 2022	267,687		$ 56	633,087	(1,050)	(364,406)
Common stock, beginning balance (in shares) at Mar. 31, 2022			56,064,509
Beginning balance at Mar. 31, 2022	317,020		$ 56	616,381	(170)	(299,247)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)			142,189
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	375			375
Stock-based compensation expense	8,207			8,207
Employee stock purchase plan (in shares)			12,539
Employee stock purchase plan	35			35
Net unrealized gain (loss) on available-for-sale securities	(491)				(491)
Net loss	(32,903)					(32,903)
Common stock, ending balance (in shares) at Jun. 30, 2022			56,219,237
Beginning balance at Jun. 30, 2022	292,243		$ 56	624,998	(661)	(332,150)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock (in shares)			220,391
Issuance of common stock upon vesting and exercise of options and vesting of restricted stock	628			628
Stock-based compensation expense	7,461			7,461
Net unrealized gain (loss) on available-for-sale securities	(389)				(389)
Net loss	(32,256)					(32,256)
Common stock, ending balance (in shares) at Sep. 30, 2022			56,439,628
Beginning balance at Sep. 30, 2022	$ 267,687		$ 56	$ 633,087	$ (1,050)	$ (364,406)
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		64 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (32,256)	$ (36,263)	$ (33,603)	$ (26,086)	$ (101,422)	$ (88,744)	$ (364,400)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	600		500		1,692	1,431
Net amortization/accretion on available-for-sale securities					185	3,175
Change in accrued interest on available-for-sale securities					856	211
Stock-based compensation expense					23,456	18,807
Noncash lease expense					1,628	1,487
Changes in operating assets and liabilities:
Prepaid expenses and other current assets					1,433	2,843
Other long-term assets					0	54
Accounts payable					409	(650)
Accrued expenses					6,161	3,288
Right-of-use operating assets and liabilities, net					(1,997)	399
Other liabilities					(799)	(1,703)
Net cash provided by (used in) operating activities					(68,398)	(59,402)
Cash flows from investing activities:
Purchase of property and equipment					(525)	(3,782)
Purchase of available-for-sale securities					(307,181)	(163,615)
Maturities of marketable securities					243,248	175,340
Sale of marketable securities					500	17,032
Net cash provided by (used in) investing activities					(63,958)	24,975
Cash flows from financing activities:
Principal payments on finance lease					0	(5)
Proceeds from issuance of common stock upon exercise of stock options					1,532	2,598
Proceeds from issuance of common stock under the employee stock purchase plan					35	817
Net cash provided by (used in) financing activities					1,567	3,410
Net increase (decrease) in cash and cash equivalents					(130,789)	(31,017)
Cash, cash equivalents and restricted cash at beginning of period		$ 200,296		$ 250,036	200,296	250,036
Cash, cash equivalents and restricted cash at end of period	69,507		219,019		69,507	219,019	69,507
Supplemental disclosures of non-cash activities:
Property and equipment additions included in accounts payable and accrued expenses					51	408
Reduction of right-of-use asset due to modification					0	(1,741)
Right-of-use asset obtained in exchange for operating lease liability					0	3,764
Cash and cash equivalents at end of period	67,481		216,993		67,481	216,993	67,481	$ 198,270	[1]
Restricted cash at end of period	2,026		2,026		2,026	2,026	2,026	2,026	[1]
Cash, cash equivalents and restricted cash at end of period	$ 69,507		$ 219,019		$ 69,507	$ 219,019	$ 69,507	$ 200,296
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF OPERATIONS AND BASIS OF PRESENTATION	NATURE OF OPERATIONS AND BASIS OF PRESENTATION Kronos Bio, Inc. (Kronos or the Company), a Delaware corporation, was incorporated on June 2, 2017. The Company is an integrated discovery through clinical development biopharmaceutical company, with a focus on developing therapeutics that target the dysregulated transcription that causes cancer and other serious diseases. The Company operates in one business segment: the development of biopharmaceutical products. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Need for Additional Capital The Company has incurred net losses since its inception of $364.4 million as of September 30, 2022. The Company expects that its cash, cash equivalents and investments as of September 30, 2022 will be sufficient to fund its operations for a period of at least one year from the date of issuance of these condensed financial statements. Management expects to incur additional losses in the future to fund its operations and conduct product research and development and recognizes the need to raise additional capital. The Company intends to raise additional capital through the issuance of equity securities, debt financings or other sources in order to continue its operations. However, if such financing is not available when needed and at adequate levels, the Company will need to reevaluate its operating plan and may be required to delay the development of its product candidates.

Significant Accounting Policies

Significant Accounting Policies, Estimates and Judgments	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS	SIGNIFICANT ACCOUNTING POLICIES, ESTIMATES AND JUDGMENTS Unaudited Interim Financial Information The accompanying condensed balance sheet as of September 30, 2022, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed statements of stockholders’ equity (deficit) as of September 30, 2022 and 2021, the condensed statements of cash flows for the nine months ended September 30, 2022 and 2021, and the financial data and other financial information disclosed in the notes to the condensed financial statements are unaudited. The unaudited interim condensed financial statements have been prepared on a basis consistent with the Company’s audited annual financial statements and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2022 and the results of its operations for the three and nine months ended September 30, 2022 and 2021. The results for the three and nine months ended September 30, 2022 are not necessarily indicative of results to be expected for the full year ending December 31, 2022, any other interim periods, or any future year or period. These 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, 2021, filed with the SEC on February 24, 2022 (Annual Report). Use of Estimates The preparation of 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 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, the accrual of research and development expenses, the fair value of investments, 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 nine months ended September 30, 2022, as compared to the significant accounting policies described in Note 2 of the “Notes to Financial Statements” of the Company’s audited financial statements included in its Annual Report. Recently Issued and Adopted Accounting Pronouncements In May 2021, the FASB issued ASU No. 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options (a consensus of the FASB Emerging Issues Task Force)

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The Company follows authoritative accounting guidance, which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company measures and reports its cash equivalents and investments at fair value. Money market funds are measured at fair value on a recurring basis using quoted prices and are classified as Level 1. Investments measured at fair value based on inputs other than quoted prices that are derived from observable market data are classified as Level 2. Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of September 30, 2022 and December 31, 2021 were as follows: September 30, 2022 Level 1 Level 2 Level 3 Fair Value (in thousands) Financial Assets: Money market funds $ 50,500 $ — $ — $ 50,500 Corporate bonds — 36,938 — 36,938 U.S. agency securities — 10,462 — 10,462 U.S. treasury securities 159,717 — — 159,717 Total financial assets $ 210,217 $ 47,400 $ — $ 257,617 December 31, 2021 Level 1 Level 2 Level 3 Fair Value (in thousands) Financial Assets: Money market funds $ 188,923 $ — $ — $ 188,923 Corporate bonds — 63,620 — 63,620 U.S. treasury securities 79,394 — — 79,394 Total financial assets $ 268,317 $ 63,620 $ — $ 331,937 The carrying amounts of accounts payable and accrued expenses approximate their fair values due to their short-term maturities. The Company’s Level 2 securities are valued using third-party pricing sources. The pricing services utilize industry standard valuation models, including both income- and market-based approaches, for which all significant inputs are observable, either directly or indirectly. The Company did not have any financial assets or liabilities as of September 30, 2022 and December 31, 2021 that required Level 3 inputs.

Investments

Investments	9 Months Ended
	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS The fair value and amortized cost of available-for-sale securities by major security type as of September 30, 2022 and December 31, 2021 were as follows: September 30, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Money market funds $ 50,500 $ — $ — $ 50,500 Corporate bonds 37,019 — (81) 36,938 U.S. agency securities 10,518 — (56) 10,462 U.S. treasury securities 160,630 — (913) 159,717 Total cash equivalents and investments $ 258,667 $ — $ (1,050) $ 257,617 December 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Money market funds $ 188,923 $ — $ — $ 188,923 Corporate bonds 63,647 2 (29) 63,620 U.S. treasury securities 79,406 — (12) 79,394 Total cash equivalents and investments $ 331,976 $ 2 $ (41) $ 331,937 These available-for-sale securities were classified on the Company’s condensed balance sheets as of September 30, 2022 and December 31, 2021 as: Fair Value September 30, 2022 December 31, 2021 (in thousands) Cash equivalents $ 54,757 $ 190,698 Short-term investments 190,774 141,239 Long-term investments 12,086 — Total cash equivalents and investments $ 257,617 $ 331,937 The fair values of available-for-sale securities by contractual maturity as of September 30, 2022 and December 31, 2021 were as follows: September 30, 2022 December 31, 2021 (in thousands) Due in 1 year or less $ 245,531 $ 143,014 Due in 1 to 2 years 12,086 — Instruments not due at a single maturity date — 188,923 Total cash equivalents and investments $ 257,617 $ 331,937 As of September 30, 2022 and December 31, 2021, the remaining contractual maturities of available-for-sale securities were less than two years. There have been no significant realized losses on available-for-sale securities for any of the periods presented in the accompanying financial statements. Based on the Company’s review of its available-for-sale securities, the Company believes that it had no other-than-temporary impairments on these securities as of September 30, 2022 and December 31, 2021 because the Company does not intend to sell these securities nor does it believe that it will be required to sell these securities before the recovery of their amortized cost basis. Gross realized gains and gross realized losses were immaterial for any of the periods presented in the accompanying financial statements. As of September 30, 2022 and December 31, 2021, unrealized losses on available-for-sale investments are not attributed to credit risk. The Company believes that an allowance for credit losses is unnecessary because the unrealized losses on certain of the Company’s marketable securities are due to market factors.

Prepaid Expenses And Other Curr

Prepaid Expenses And Other Current Assets	9 Months Ended
	Sep. 30, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
PREPAID EXPENSES AND OTHER CURRENT ASSETS	PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets consisted of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Accrued interest on short-term available-for-sale securities $ 607 $ 816 Prepaid equipment service contracts 321 360 Prepaid external research and development and outside services 4,144 3,074 Prepaid software 717 624 Prepaid insurance 129 2,644 Prepaid rent and other 457 527 Total prepaid expenses and other current assets $ 6,375 $ 8,045

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET Property and equipment, net consisted of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Property and equipment: Lab equipment $ 8,464 $ 8,164 Leasehold improvements 9,348 9,335 Furniture and fixtures 619 596 Computer equipment 58 44 Total property and equipment 18,489 18,139 Less: Accumulated depreciation and amortization (4,951) (3,259) Total property and equipment, net $ 13,538 $ 14,880 Depreciation and amortization expense was $0.6 million and $0.5 million for the three months ended September 30, 2022 and 2021, respectively and $1.7 million and $1.4 million for the nine months ended September 30, 2022 and 2021, respectively.

Accrued Expenses and Current Po

Accrued Expenses and Current Portion of Other Liabilities	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
ACCRUED EXPENSES AND CURRENT PORTION OF OTHER LIABILITIES	ACCRUED EXPENSES AND CURRENT PORTION OF OTHER LIABILITIES Accrued expenses consisted of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Accrued compensation $ 3,195 $ 4,570 External research and development 10,923 2,655 Accrued outside services 839 1,598 Other accrued expenses 37 240 Total accrued expenses $ 14,994 $ 9,063 September 30, 2022 December 31, 2021 (in thousands) Current portion of unvested early exercised share liability 1,056 1,364 ESPP withholdings 354 92 Total current portion of other liabilities $ 1,410 $ 1,456

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION 2020 Equity Incentive Plan In October 2020, the Company adopted its 2020 Equity Incentive Plan (the 2020 Plan) which replaced the 2017 Equity Incentive Plan (Prior Plan) upon completion of the IPO. The 2020 Plan provides for the grant of incentive stock options or nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance awards and other forms of awards to employees, directors, and consultants of the Company. The number of shares of common stock reserved for issuance under the 2020 Plan will automatically increase each year for a period of ten years, beginning in 2021 and continuing through 2030, in an amount equal to (1) 5.0% of the total number of shares of the Company’s common stock outstanding on December 31 of the immediately preceding year, or (2) a lesser number of shares determined by the Board of Directors no later than December 31 of the immediately preceding year. As of September 30, 2022, the maximum number of shares of common stock that may be issued was 17,568,821 shares. The Company recognizes the impact of forfeitures on stock-based compensation expense as forfeitures occur. The Company applies the straight-line method of expense recognition to all awards with only service-based vesting conditions. Options shall not have an exercise price less than 100% of the fair market value of the Company’s common stock on the grant date. Vesting periods are determined at the discretion of the Board of Directors. Stock options typically vest over four years. The maximum contractual term is 10 years. As of September 30, 2022, there were 4,046,541 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, 2022 is summarized as follows: Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in thousands) Balance, December 31, 2021 6,590,400 $ 14.33 Granted 2,708,563 6.51 Forfeited (957,876) 17.76 Exercised (591,463) 2.58 Balance, September 30, 2022 7,749,624 $ 12.07 8.24 $ 1,372 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, 2022. There was no future tax benefit related to options exercised, as the Company had accumulated net operating losses as of September 30, 2022 and December 31, 2021. The weighted-average grant-date fair value per share of stock options granted, using the Black-Scholes option pricing model, was $5.52 during the nine months ended September 30, 2022. As of September 30, 2022 and December 31, 2021, there was $40.4 million and $49.9 million of unrecognized stock-based compensation related to stock options, respectively, which is expected to be recognized over a weighted-average period of 2.48 and 2.93 years, respectively. 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 increases 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 and sold zero and 12,539 shares of common stock during the three and nine months ended September 30, 2022 and zero and 50,569 shares of common stock during the three and nine months ended September 30, 2021, under the ESPP. The Company has 1,705,871 shares reserved for future issuance as of September 30, 2022 . Restricted Stock Restricted stock awards and units as of September 30, 2022 are summarized as follows: Number of Restricted Stock Weighted-Average Grant Date Fair Value Weighted-Average Remaining Vesting Life Aggregate Intrinsic Value (in years) (in thousands) Unvested, December 31, 2021 787,719 $ 26.88 Granted 1,853,312 5.92 Vested and converted to shares (132,299) 24.23 Forfeited (173,966) 13.06 Unvested, September 30, 2022 2,334,766 $ 11.51 1.53 $ 7,821 As of September 30, 2022, there was $18.7 million of unrecognized stock-based compensation related to RSUs, which is expected to be recognized over a weighted average period of 1.52 years. As of September 30, 2022, there was $0.3 million of unrecognized stock-based compensation related to RSAs, which is expected to be recognized over a weighted average period of 1.83 years. Stock-Based Compensation Summary Total stock-based compensation expense related to stock options, restricted stock units, restricted stock awards and the employee stock purchase plan for the three and nine months ended September 30, 2022 and 2021 as follows: Three months ended September 30, Nine months ended September 30, 2022 2021 2022 2021 (in thousands) (in thousands) Research and development expenses $ 3,500 $ 3,525 $ 11,355 $ 9,553 General and administrative expenses 3,961 3,612 12,101 9,254 Total stock-based compensation expense $ 7,461 $ 7,137 $ 23,456 $ 18,807 Early Exercised Options The Company allows certain of its employees and its consultants to exercise options granted under the Prior Plan prior to vesting. The shares related to early exercised stock options are subject to the Company’s lapsing repurchase right upon termination of employment or service on the Board of Directors at the lesser of the original purchase price or fair market value at the time of repurchase. In order to vest, the holders are required to provide continued service to the Company. The early exercise by an employee or consultant of a stock option is not considered to be a substantive exercise for accounting purposes, and therefore the payment received by the employer for the exercise price is recognized as a liability. For accounting purposes, unvested early exercised shares are not considered issued and outstanding and therefore not reflected as issued and outstanding in the accompanying balance sheets or the accompanying statements of stockholders' equity (deficit) until the awards vest. The deposits received are initially recorded in current portion of other liabilities and other noncurrent liabilities for the noncurrent portion. The liabilities are reclassified to common stock and paid-in capital as the repurchase right lapses. At September 30, 2022 and December 31, 2021, there was $1.1 million and $1.4 million recorded in current portion of other liabilities, and $0.4 million and $1.1 million recorded in other noncurrent liabilities, respectively, related to shares held by employees and nonemployees that were subject to repurchase.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
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, 2022 and 2021. 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 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, 2022 and 2021. The Company has not identified any new uncertain tax positions as of September 30, 2022. 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.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
NET LOSS PER SHARE	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, 2022 and 2021: Three months ended September 30, Nine months ended September 30, 2022 2021 2022 2021 (in thousands, except share and per share amounts) (in thousands, except share and per share amounts) Net loss $ (32,256) $ (33,603) $ (101,422) $ (88,744) Weighted-average common stock outstanding, basic and diluted 56,318,571 54,977,085 56,093,091 54,549,747 Net loss per share, basic and diluted $ (0.57) $ (0.61) $ (1.81) $ (1.63) The Company’s potentially dilutive securities, which include options to purchase shares of the Company's common stock and restricted stock subject to future vesting, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share is the same. The Company excluded the following potential shares of common stock, presented based on amounts outstanding at each stated period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: September 30, 2022 September 30, 2021 Stock options to purchase common stock 7,362,762 5,768,855 Early exercised stock options subject to future vesting 386,862 981,866 Restricted stock awards subject to future vesting 62,870 124,066 Restricted stock units subject to future vesting 2,271,896 892,208 Expected shares to be purchased under Employee Stock Purchase Plan 829,820 122,693 Total 10,914,210 7,889,688

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES R&D Services Agreement In October 2021, the Company entered into an agreement for research and development services (Tempus Agreement) with Tempus Labs, Inc. (Tempus), pursuant to which Tempus agreed to provide the Company with research and development services for a period of three years. The three primary services are analytical services, data licensing, and organoid services. The Company intends to utilize the services contemplated under the Tempus Agreement to advance the development of KB-0742 and lanraplenib. In consideration for the access to the services throughout the term of the Tempus Agreement, the Company has agreed to pay an annual minimum commitment of $1.5 million in year one, $2.0 million in year two, and $2.5 million in year three. Payments are made in quarterly installments. In addition, the Company is required to make milestone payments upon successful achievement of certain regulatory milestones for KB-0742, lanraplenib, and other discovery pipeline compounds up to a combined maximum of $22.4 million. For each milestone payment that becomes due, the Company has the right to pay up to 50% of such milestone payment amount in shares of its common stock as long as certain regulatory requirements are met. As of September 30, 2022, there were no milestone payments due. 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 and royalty payments upon successful achievement of certain regulatory and sales milestones for the acquired assets. Upon initiation of our registrational Phase 3 clinical trial of entospletinib in combination with induction chemotherapy in acute myeloid leukemia patients with NPM1 mutations in December 2021, we paid a milestone to Gilead of $29.0 million. We are currently unable to estimate the timing or likelihood of achieving remaining milestones or generating future product sales. Purchase Commitments In the normal course of business, the Company enters into contracts with CROs for preclinical and clinical studies and other vendors for services and products. These agreements generally provide for termination or cancellation, other than for costs already incurred and certain wind down costs that may be associated with the termination of a contract or clinical trial program. Contingencies In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications. The Company’s exposure under these agreements is unknown, because it involves claims that may be made against the Company in the future, but have not yet been made. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. Indemnification In accordance with the Company’s amended and restated certificate of incorporation and amended and restated bylaws, the Company has indemnification obligations to its officers and directors for certain events or occurrences, subject to certain limits, while they are serving in such capacity. There have been no claims to date, and the Company has a directors and officers liability insurance policy that may enable it to recover a portion of any amounts paid for future claims.

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
LEASES	LEASES In March 2020, the Company entered into an 11-year lease agreement to move its research and development operations from 21 Erie Street, Cambridge, Massachusetts, to a 40,514 square-feet facility at 301 Binney Street, Cambridge, Massachusetts (Cambridge facility). The lease commenced on February 28, 2020 with an initial annual base rent of $4.1 million. The initial rent payment was paid as of September 30, 2020, with rent payments escalating 3.0% annually after the initial 12 payments. The Company executed a letter of credit for $2.0 million in connection with the lease. The lease includes $3.7 million in certain tenant improvement allowances, which the Company included in its calculation of the right-of-use asset in the lease at commencement. As of September 30, 2022, $3.7 million in improvement costs incurred by the Company were reimbursed by the lessor and are now included within the total lease liability. In connection with the lease, the Company recognized an operating lease right-of-use asset of $22.4 million and $23.6 million and an aggregate lease liability of $28.0 million and $29.7 million as of September 30, 2022 and December 31, 2021, respectively. The remaining lease term is 8 years and 5 months, and the estimated incremental borrowing rate is 8.50%. In February 2021, the Company entered into a new lease agreement for its office space in San Mateo, California to move from its suites, totaling 8,075 square-feet, to a larger suite totaling 17,340 square-feet, and relocated in the third quarter of 2021. The Company accounted for this change in lease term of the original suites as a modification of the originally amended lease. As a result of the modification, the operating right-of-use asset and lease liability were remeasured as of the modification date. The initial annual base rent for the new space was $1.2 million, and such amount increases by 3% annually on each anniversary of the new premises commencement date. In connection with the larger space leased, the Company has also made an additional one-time cash security deposit in the amount of $59,000. The new lease commenced in April 2021 and the new lease agreement extends the termination date from April 30, 2025 to August 31, 2026. In connection with the lease, the Company recognized an operating lease right-of-use asset of $2.9 million and $3.3 million and an aggregate lease liability of $3.8 million and $4.1 million as of September 30, 2022 and December 31, 2021, respectively. The remaining lease term is 3 years and 9 months, and the estimated incremental borrowing rate is 11.18%. The following table summarizes the presentation of the Company’s operating leases in its balance sheets as of September 30, 2022 and December 31, 2021: Balance Sheet Caption September 30, 2022 December 31, 2021 (in thousands) Assets: Operating lease assets $ 25,276 $ 26,904 Liabilities: Current portion of operating lease liabilities $ 2,239 $ 2,109 Noncurrent operating lease liabilities 29,526 31,653 Total operating lease liabilities $ 31,765 $ 33,762 The effect of finance lease costs in the Company’s statements of operations and comprehensive loss was immaterial for the three and nine months ended September 30, 2022 and 2021. The following table summarizes the effect of operating lease costs in the Company’s statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021 : Statement of Operations and Comprehensive Loss Caption Three months ended September 30, Nine months ended September 30, 2022 2021 2022 2021 (in thousands) (in thousands) Research and development $ 767 $ 767 $ 2,301 $ 2,542 General and administrative 511 256 1,532 1,245 Total operating lease cost $ 1,278 $ 1,023 $ 3,833 $ 3,787 The Company made cash payments of $1.9 million, $4.2 million, $1.0 million, and $3.3 million under the lease agreements during the three and nine months ended September 30, 2022 and 2021, respectively. The undiscounted future non-cancellable lease payments under the Company's operating leases as of September 30, 2022 for the next five years and thereafter is expected to be as follows: Period Ending December 31, Amount (in thousands) Remaining three months of 2022 $ 812 2023 5,581 2024 5,749 2025 5,921 2026 and thereafter 26,711 Total undiscounted lease payments 44,774 Less: Present value adjustment (13,009) Present value of operating lease liabilities $ 31,765

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
RELATED PARTIES	RELATED PARTIES On December 1, 2017, the Company entered into a services agreement with Two River Consulting, LLC (Two River) to provide various clinical development, operational, managerial, accounting and financial, and administrative services to the Company. Arie Belldegrun, M.D., FACS, the Chairman of the Board of Directors, is the Chairman of Two River. Mr. Joshua Kazam and Mr. David Tanen, each a director of the Company, are each partners of Two River. Mr. Christopher Wilfong, a strategic advisor to the Company, is an Operating Partner of Two River and Mr. Sean Algeo, serving as a financial consultant to the Company, is the Chief Financial Officer of Two River. During the three and nine months ended September 30, 2022 and 2021, the Company incurred expenses of $30,000, $71,000, zero and $0.3 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. Rebecka Belldegrun, M.D., who served as a director of the Company through January 25, 2021, is the President and Chief Executive Officer of Bellco. During the three and nine months ended September 30, 2022 and 2021, the Company incurred expense of $6,300, $18,900, $6,300, and $18,900, respectively, for these services.

Significant Accounting Polici_2

Significant Accounting Policies, Estimates and Judgments (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying condensed balance sheet as of September 30, 2022, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed statements of stockholders’ equity (deficit) as of September 30, 2022 and 2021, the condensed statements of cash flows for the nine months ended September 30, 2022 and 2021, and the financial data and other financial information disclosed in the notes to the condensed financial statements are unaudited. The unaudited interim condensed financial statements have been prepared on a basis consistent with the Company’s audited annual financial statements and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2022 and the results of its operations for the three and nine months ended September 30, 2022 and 2021. The results for the three and nine months ended September 30, 2022 are not necessarily indicative of results to be expected for the full year ending December 31, 2022, any other interim periods, or any future year or period. These 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, 2021, filed with the SEC on February 24, 2022 (Annual Report).
Use of Estimates	Use of Estimates The preparation of 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 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, the accrual of research and development expenses, the fair value of investments, 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.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued and Adopted Accounting Pronouncements In May 2021, the FASB issued ASU No. 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options (a consensus of the FASB Emerging Issues Task Force)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
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, 2022 and December 31, 2021 were as follows: September 30, 2022 Level 1 Level 2 Level 3 Fair Value (in thousands) Financial Assets: Money market funds $ 50,500 $ — $ — $ 50,500 Corporate bonds — 36,938 — 36,938 U.S. agency securities — 10,462 — 10,462 U.S. treasury securities 159,717 — — 159,717 Total financial assets $ 210,217 $ 47,400 $ — $ 257,617 December 31, 2021 Level 1 Level 2 Level 3 Fair Value (in thousands) Financial Assets: Money market funds $ 188,923 $ — $ — $ 188,923 Corporate bonds — 63,620 — 63,620 U.S. treasury securities 79,394 — — 79,394 Total financial assets $ 268,317 $ 63,620 $ — $ 331,937

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Investments Classified by Contractual Maturity Date	The fair value and amortized cost of available-for-sale securities by major security type as of September 30, 2022 and December 31, 2021 were as follows: September 30, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Money market funds $ 50,500 $ — $ — $ 50,500 Corporate bonds 37,019 — (81) 36,938 U.S. agency securities 10,518 — (56) 10,462 U.S. treasury securities 160,630 — (913) 159,717 Total cash equivalents and investments $ 258,667 $ — $ (1,050) $ 257,617 December 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) Money market funds $ 188,923 $ — $ — $ 188,923 Corporate bonds 63,647 2 (29) 63,620 U.S. treasury securities 79,406 — (12) 79,394 Total cash equivalents and investments $ 331,976 $ 2 $ (41) $ 331,937 These available-for-sale securities were classified on the Company’s condensed balance sheets as of September 30, 2022 and December 31, 2021 as: Fair Value September 30, 2022 December 31, 2021 (in thousands) Cash equivalents $ 54,757 $ 190,698 Short-term investments 190,774 141,239 Long-term investments 12,086 — Total cash equivalents and investments $ 257,617 $ 331,937 The fair values of available-for-sale securities by contractual maturity as of September 30, 2022 and December 31, 2021 were as follows: September 30, 2022 December 31, 2021 (in thousands) Due in 1 year or less $ 245,531 $ 143,014 Due in 1 to 2 years 12,086 — Instruments not due at a single maturity date — 188,923 Total cash equivalents and investments $ 257,617 $ 331,937

Prepaid Expenses And Other Cu_2

Prepaid Expenses And Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Assets	Prepaid expenses and other current assets consisted of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Accrued interest on short-term available-for-sale securities $ 607 $ 816 Prepaid equipment service contracts 321 360 Prepaid external research and development and outside services 4,144 3,074 Prepaid software 717 624 Prepaid insurance 129 2,644 Prepaid rent and other 457 527 Total prepaid expenses and other current assets $ 6,375 $ 8,045

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment, net consisted of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Property and equipment: Lab equipment $ 8,464 $ 8,164 Leasehold improvements 9,348 9,335 Furniture and fixtures 619 596 Computer equipment 58 44 Total property and equipment 18,489 18,139 Less: Accumulated depreciation and amortization (4,951) (3,259) Total property and equipment, net $ 13,538 $ 14,880

Accrued Expenses And Current _2

Accrued Expenses And Current Portion Of Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued expenses consisted of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Accrued compensation $ 3,195 $ 4,570 External research and development 10,923 2,655 Accrued outside services 839 1,598 Other accrued expenses 37 240 Total accrued expenses $ 14,994 $ 9,063
Other Current Liabilities	Current portion of other liabilities consist of the following as of September 30, 2022 and December 31, 2021: September 30, 2022 December 31, 2021 (in thousands) Current portion of unvested early exercised share liability 1,056 1,364 ESPP withholdings 354 92 Total current portion of other liabilities $ 1,410 $ 1,456

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock Option Activity	Stock option activity under the 2020 Plan as of September 30, 2022 is summarized as follows: Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in thousands) Balance, December 31, 2021 6,590,400 $ 14.33 Granted 2,708,563 6.51 Forfeited (957,876) 17.76 Exercised (591,463) 2.58 Balance, September 30, 2022 7,749,624 $ 12.07 8.24 $ 1,372
Schedule of Nonvested Share Activity	Restricted stock awards and units as of September 30, 2022 are summarized as follows: Number of Restricted Stock Weighted-Average Grant Date Fair Value Weighted-Average Remaining Vesting Life Aggregate Intrinsic Value (in years) (in thousands) Unvested, December 31, 2021 787,719 $ 26.88 Granted 1,853,312 5.92 Vested and converted to shares (132,299) 24.23 Forfeited (173,966) 13.06 Unvested, September 30, 2022 2,334,766 $ 11.51 1.53 $ 7,821
Stock-based Compensation, Classified in Statements of Operations	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, 2022 and 2021 as follows: Three months ended September 30, Nine months ended September 30, 2022 2021 2022 2021 (in thousands) (in thousands) Research and development expenses $ 3,500 $ 3,525 $ 11,355 $ 9,553 General and administrative expenses 3,961 3,612 12,101 9,254 Total stock-based compensation expense $ 7,461 $ 7,137 $ 23,456 $ 18,807

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Earnings 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, 2022 and 2021: Three months ended September 30, Nine months ended September 30, 2022 2021 2022 2021 (in thousands, except share and per share amounts) (in thousands, except share and per share amounts) Net loss $ (32,256) $ (33,603) $ (101,422) $ (88,744) Weighted-average common stock outstanding, basic and diluted 56,318,571 54,977,085 56,093,091 54,549,747 Net loss per share, basic and diluted $ (0.57) $ (0.61) $ (1.81) $ (1.63)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The Company excluded the following potential shares of common stock, presented based on amounts outstanding at each stated period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: September 30, 2022 September 30, 2021 Stock options to purchase common stock 7,362,762 5,768,855 Early exercised stock options subject to future vesting 386,862 981,866 Restricted stock awards subject to future vesting 62,870 124,066 Restricted stock units subject to future vesting 2,271,896 892,208 Expected shares to be purchased under Employee Stock Purchase Plan 829,820 122,693 Total 10,914,210 7,889,688

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Assets and Liabilities, Operating Leases, Lessee	The following table summarizes the presentation of the Company’s operating leases in its balance sheets as of September 30, 2022 and December 31, 2021: Balance Sheet Caption September 30, 2022 December 31, 2021 (in thousands) Assets: Operating lease assets $ 25,276 $ 26,904 Liabilities: Current portion of operating lease liabilities $ 2,239 $ 2,109 Noncurrent operating lease liabilities 29,526 31,653 Total operating lease liabilities $ 31,765 $ 33,762
Summary of Lease Costs	The following table summarizes the effect of operating lease costs in the Company’s statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021 : Statement of Operations and Comprehensive Loss Caption Three months ended September 30, Nine months ended September 30, 2022 2021 2022 2021 (in thousands) (in thousands) Research and development $ 767 $ 767 $ 2,301 $ 2,542 General and administrative 511 256 1,532 1,245 Total operating lease cost $ 1,278 $ 1,023 $ 3,833 $ 3,787
Schedule of Maturities on Lease Liabilities	The undiscounted future non-cancellable lease payments under the Company's operating leases as of September 30, 2022 for the next five years and thereafter is expected to be as follows: Period Ending December 31, Amount (in thousands) Remaining three months of 2022 $ 812 2023 5,581 2024 5,749 2025 5,921 2026 and thereafter 26,711 Total undiscounted lease payments 44,774 Less: Present value adjustment (13,009) Present value of operating lease liabilities $ 31,765

Nature of Operations and Basi_2

Nature of Operations and Basis of Presentation (Details) $ in Thousands	3 Months Ended						9 Months Ended		64 Months Ended
	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments | segment							1
Net loss | $	$ 32,256	$ 32,903	$ 36,263	$ 33,603	$ 29,055	$ 26,086	$ 101,422	$ 88,744	$ 364,400

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 257,617	$ 331,937
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	50,500	188,923
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	36,938	63,620
U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	10,462
U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	159,717	79,394
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	210,217	268,317
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	50,500	188,923
Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	0	0
Level 1 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	0
Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	159,717	79,394
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	47,400	63,620
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	36,938	63,620
Level 2 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	10,462
Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	0	0
Level 3 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	0
Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value	$ 0	$ 0

Investments - Fair Value and Am

Investments - Fair Value and Amortized Cost (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Money market funds, amortized cost	$ 54,757	$ 190,698
Unrealized Gains	0	2
Unrealized Losses	(1,050)	(41)
Total cash equivalents and investments, amortized cost	258,667	331,976
Total cash equivalents and investments, fair value	257,617	331,937
Money market funds
Schedule of Held-to-maturity Securities [Line Items]
Money market funds, amortized cost	50,500	188,923
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	37,019	63,647
Unrealized Gains	0	2
Unrealized Losses	(81)	(29)
Fair Value	36,938	63,620
U.S. agency securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	10,518
Unrealized Gains	0
Unrealized Losses	(56)
Fair Value	10,462
U.S. treasury securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	160,630	79,406
Unrealized Gains	0	0
Unrealized Losses	(913)	(12)
Fair Value	$ 159,717	$ 79,394

Investments - Balance Sheet (De

Investments - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Cash equivalents	$ 54,757	$ 190,698
Short-term investments	190,774	141,239	[1]
Long-term investments	12,086	0	[1]
Total cash equivalents and investments	$ 257,617	$ 331,937
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Investments - Contractual Matur

Investments - Contractual Maturity (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Due in 1 year or less	$ 245,531,000	$ 143,014,000
Due in 1 to 2 years	12,086,000	0
Instruments not due at a single maturity date	0	188,923,000
Total cash equivalents and investments	257,617,000	331,937,000
Other-than-temporary impairments on available-for-sale securities	$ 0	$ 0

Prepaid Expenses And Other Cu_3

Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Accrued interest on short-term available-for-sale securities	$ 607	$ 816
Prepaid equipment service contracts	321	360
Prepaid external research and development and outside services	4,144	3,074
Prepaid software	717	624
Prepaid insurance	129	2,644
Prepaid rent and other	457	527
Prepaid expenses and other current assets	$ 6,375	$ 8,045	[1]
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 18,489		$ 18,489		$ 18,139
Less: Accumulated depreciation and amortization	(4,951)		(4,951)		(3,259)
Total property and equipment, net	13,538		13,538		14,880	[1]
Depreciation and amortization	600	$ 500	1,692	$ 1,431
Lab equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,464		8,464		8,164
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	9,348		9,348		9,335
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	619		619		596
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 58		$ 58		$ 44
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Accrued Expenses And Current _3

Accrued Expenses And Current Portion Of Other Liabilities - Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued compensation	$ 3,195	$ 4,570
External research and development	10,923	2,655
Accrued outside services	839	1,598
Other accrued expenses	37	240
Total accrued expenses	$ 14,994	$ 9,063	[1]
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Accrued Expenses And Current _4

Accrued Expenses And Current Portion Of Other Liabilities - Current Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Current portion of unvested early exercised share liability	$ 1,056	$ 1,364
ESPP withholdings	354	92
Total current portion of other liabilities	$ 1,410	$ 1,456	[1]
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value, options granted (in dollars per share)				$ 5.52
Stock options, unrecognized cost		$ 40,400		$ 40,400		$ 49,900
Current liabilities related to shares that were subject to repurchase		1,056		1,056		1,364
Current portion of other liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Current liabilities related to shares that were subject to repurchase		1,100		1,100		1,400
Other noncurrent liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-current liabilities related to shares that were subject to repurchase		$ 400		$ 400		$ 1,100
2020 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Shares that may be issued, percent increase as total of common stock outstanding	5%
Number of shares that may have been issued (in shares)		17,568,821		17,568,821
Options, exercise price, percent of fair market value	100%
Vesting period	4 years
Number of shares reserved for future issuance (in shares)		4,046,541		4,046,541
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options recognized, weighted average period				2 years 5 months 23 days		2 years 11 months 4 days
Expected shares to be purchased under Employee Stock Purchase Plan | The ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares that may have been issued (in shares)	688,000
Number of shares reserved for future issuance (in shares)		1,705,871		1,705,871
Number of shares that may be issued, increase percentage	1%
Number of shares that may be issued, increase (in shares)	1,376,000
Employee stock purchase plan (in shares)		0	0	12,539	50,569
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options recognized, weighted average period				1 year 6 months 7 days
Unrecognized stock based compensation		$ 18,700		$ 18,700
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options recognized, weighted average period				1 year 9 months 29 days
Unrecognized stock based compensation		$ 300		$ 300

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares
Number of Options
Beginning Balance (in shares) | shares	6,590,400
Granted (in shares) | shares	2,708,563
Forfeited (in shares) | shares	(957,876)
Exercised (in shares) | shares	(591,463)
Ending Balance (in shares) | shares	7,749,624
Weighted-Average Exercise Price
Beginning Balance (dollars per share) | $ / shares	$ 14.33
Granted (dollars per share) | $ / shares	6.51
Forfeited (dollars per share) | $ / shares	17.76
Exercised (dollars per share) | $ / shares	2.58
Ending Balance (dollars per share) | $ / shares	$ 12.07
Stock Option Activity, Additional Disclosures [Abstract]
Balance, Weighted-Average Remaining Contractual Term	8 years 2 months 26 days
Balance, Aggregate Intrinsic Value | $	$ 1,372

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Awards Activity (Details) - Restricted Stock And Restricted Stock Units $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares
Number of Restricted Stock
Unvested Beginning Balance (in shares) | shares	787,719
Granted - restricted stock awards and units (in shares) | shares	1,853,312
Vested and converted to shares (in shares) | shares	(132,299)
Forfeited (in shares) | shares	(173,966)
Unvested Ending Balance (in shares) | shares	2,334,766
Weighted-Average Grant Date Fair Value
Unvested Beginning Balance (in dollars per share) | $ / shares	$ 26.88
Granted - restricted stock awards and units (in dollars per share) | $ / shares	5.92
Vested and converted to shares (in dollars per share) | $ / shares	24.23
Forfeited (in dollars per share) | $ / shares	13.06
Unvested Ending Balance (in dollars per share) | $ / shares	$ 11.51
Unvested, Weighted Average Remaining Vesting Life	1 year 6 months 10 days
Unvested, Aggregate Intrinsic Value | $	$ 7,821

Stock-Based Compensation - Re_2

Stock-Based Compensation - Restricted Stock Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 7,461	$ 7,137	$ 23,456	$ 18,807
Research and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,500	3,525	11,355	9,553
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,961	$ 3,612	$ 12,101	$ 9,254

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0	$ 0	$ 0

Net Loss Per Share (Details)

Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended		64 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022
Earnings Per Share [Abstract]
Net loss	$ (32,256)	$ (32,903)	$ (36,263)	$ (33,603)	$ (29,055)	$ (26,086)	$ (101,422)	$ (88,744)	$ (364,400)
Weighted-average shares of common stock, basic (in shares)	56,318,571			54,977,085			56,093,091	54,549,747
Weighted-average shares of common stock, diluted (in shares)	56,318,571			54,977,085			56,093,091	54,549,747
Net loss per share, basic (in dollars per share)	$ (0.57)			$ (0.61)			$ (1.81)	$ (1.63)
Net loss per share, diluted (in dollars per share)	$ (0.57)			$ (0.61)			$ (1.81)	$ (1.63)

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	10,914,210	7,889,688
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)	7,362,762	5,768,855
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)	386,862	981,866
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)	62,870	124,066
Restricted stock units subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	2,271,896	892,208
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)	829,820	122,693

Commitment and Contingencies -

Commitment and Contingencies - Narrative (Details) - USD ($) $ in Millions	1 Months Ended
	Dec. 31, 2021	Oct. 31, 2021
Research And Development Services | Tempus Labs, Inc.
Schedule Of Asset Acquisition [Line Items]
Services contract term		3 years
Annual minimum commitment payment in year one		$ 1.5
Annual minimum commitment payment in year two		2
Annual minimum commitment payment in year three		2.5
Sales milestone payment		$ 22.4
Sales milestone payment in shares of common stock, percent threshold		50%
Asset Purchase Agreement
Schedule Of Asset Acquisition [Line Items]
Sales milestone payment	$ 29

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Feb. 28, 2021 USD ($) ft²	Mar. 31, 2020 USD ($) ft²	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)		Sep. 30, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets			$ 25,276		$ 25,276		$ 26,904	[1]
Lease liabilities			31,765		31,765		33,762
Lease payments			1,900	$ 1,000	4,200	$ 3,300
301 Binney Street, Cambridge, Massachusetts
Lessee, Lease, Description [Line Items]
Lease term		11 years
Facility size | ft²		40,514
Initial annual base rent		$ 4,100
Escalating rent payments, percent		3%
Letter of credit									$ 2,000
Tenant improvement allowances									$ 3,700
Improvement costs incurred, reimbursed by lessor					3,700
Operating lease right-of-use assets			22,400		22,400		23,600
Lease liabilities			$ 28,000		$ 28,000		29,700
Remaining lease term			8 years 5 months		8 years 5 months
Incremental borrowing rate			8.50%		8.50%
San Mateo, California. Original Lease
Lessee, Lease, Description [Line Items]
Facility size | ft²	8,075
San Mateo, California. February 2021 Lease Agreement
Lessee, Lease, Description [Line Items]
Facility size | ft²	17,340
Initial annual base rent	$ 1,200
Escalating rent payments, percent	3%
Operating lease right-of-use assets			$ 2,900		$ 2,900		3,300
Lease liabilities			$ 3,800		$ 3,800		$ 4,100
Remaining lease term			3 years 9 months		3 years 9 months
Incremental borrowing rate			11.18%		11.18%
Security deposit	$ 59
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information - Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets:
Operating lease assets	$ 25,276	$ 26,904	[1]
Liabilities:
Current portion of operating lease liabilities	2,239	2,109	[1]
Noncurrent operating lease liabilities	29,526	31,653	[1]
Total operating lease liabilities	$ 31,765	$ 33,762
[1]The balance sheet as of December 31, 2021 is derived from the audited financial statements as of that date.

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 1,278	$ 1,023	$ 3,833	$ 3,787
Research and development expenses
Lessee, Lease, Description [Line Items]
Operating lease cost	767	767	2,301	2,542
General and administrative
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 511	$ 256	$ 1,532	$ 1,245

Leases - Schedule of Maturities

Leases - Schedule of Maturities on Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Leases [Abstract]
Remaining three months of 2022	$ 812
2023	5,581
2024	5,749
2025	5,921
2026 and thereafter	26,711
Total undiscounted lease payments	44,774
Less: Present value adjustment	(13,009)
Present value of operating lease liabilities	$ 31,765	$ 33,762

Related Parties (Details)

Related Parties (Details) - Affiliated Entity - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Two River Consulting, LLC
Related Party Transaction [Line Items]
Expenses from transaction with related party	$ 30,000	$ 0	$ 71,000	$ 300,000
Bellco Capital, LLC
Related Party Transaction [Line Items]
Expenses from transaction with related party	$ 6,300	$ 6,300	$ 18,900	$ 18,900