Allogene Therapeutics (ALLO) 10-Q 2 Nov 22 2022 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2022	Oct. 31, 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	001-38693
Entity Registrant Name	Allogene Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3562771
Entity Address, Address Line One	210 East Grand Avenue
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	457-2700
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	ALLO
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		144,210,154
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Central Index Key	0001737287
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 74,357	$ 173,314
Short-term investments	477,872	283,988
Prepaid expenses and other current assets	16,832	14,021
Total current assets	569,061	471,323
Long-term investments	85,108	352,179
Operating lease right-of-use asset	85,245	58,030
Property and equipment, net	114,442	122,990
Restricted cash	10,292	10,292
Other long-term assets	9,378	5,815
Equity method investment	14,046	18,005
Total assets	887,572	1,038,634
Current liabilities:
Accounts payable	11,045	10,255
Accrued and other current liabilities	36,938	37,496
Deferred revenue	889	423
Total current liabilities	48,872	48,174
Lease liability, non-current	96,706	69,929
Other long-term liabilities	2,033	4,125
Total liabilities	147,611	122,228
Commitments and Contingencies (Notes 6 and 7)
Stockholders’ equity:
Preferred stock, $0.001 par value: 10,000,000 shares authorized as of September 30, 2022 and December 31, 2021; no shares were issued and outstanding as of September 30, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value: 400,000,000 shares authorized as of September 30, 2022 and 200,000,000 shares authorized as of December 31, 2021; 144,031,588 and 142,623,065 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	144	142
Additional paid-in capital	1,893,908	1,822,179
Accumulated deficit	(1,141,133)	(903,348)
Accumulated other comprehensive loss	(12,958)	(2,567)
Total stockholders’ equity	739,961	916,406
Total liabilities and stockholders’ equity	$ 887,572	$ 1,038,634

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
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)	400,000,000	200,000,000
Common stock, shares issued (in shares)	144,031,588	142,623,065
Common stock, shares outstanding (in shares)	144,031,588	142,623,065

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues
Collaboration revenue - related party	$ 49	$ 49	$ 196	$ 38,438
Operating expenses:
Research and development	63,641	58,720	180,968	166,193
General and administrative	18,897	18,999	58,303	54,144
Total operating expenses	82,538	77,719	239,271	220,337
Loss from operations	(82,489)	(77,670)	(239,075)	(181,899)
Other income (expense), net:
Interest and other income, net	1,002	393	1,809	1,528
Other expenses	(1,661)	(909)	(519)	(1,766)
Total other income (expense), net	(659)	(516)	1,290	(238)
Net loss	(83,148)	(78,186)	(237,785)	(182,137)
Other comprehensive loss:
Net unrealized loss on available-for-sale investments	(1,486)	(64)	(10,391)	(666)
Net comprehensive loss	$ (84,634)	$ (78,250)	$ (248,176)	$ (182,803)
Net loss per share, basic (in dollars per share)	$ (0.58)	$ (0.57)	$ (1.67)	$ (1.35)
Net loss per share, diluted (in dollars per share)	$ (0.58)	$ (0.57)	$ (1.67)	$ (1.35)
Weighted-average number of shares used in computing net loss per share, basic (in shares)	143,661,721	137,025,698	142,809,469	134,690,310
Weighted-average number of shares used in computing net loss per share, diluted (in shares)	143,661,721	137,025,698	142,809,469	134,690,310

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2020		140,474,305
Beginning balance at Dec. 31, 2020	$ 1,079,617	$ 140	$ 1,725,552	$ (646,343)	$ 268
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)		897,744
Issuance of common stock upon exercise of stock options and vesting of RSUs	4,060	$ 1	4,059
Vesting of early exercised common stock	710		710
Stock-based compensation	16,792		16,792
Employee stock purchase plan (in shares)		98,026
Employee stock purchase plan	1,984		1,984
Net loss	(33,015)			(33,015)
Net unrealized loss on available-for-sale investments	(369)				(369)
Ending balance (in shares) at Mar. 31, 2021		141,470,075
Ending balance at Mar. 31, 2021	1,069,779	$ 141	1,749,097	(679,358)	(101)
Beginning balance (in shares) at Dec. 31, 2020		140,474,305
Beginning balance at Dec. 31, 2020	$ 1,079,617	$ 140	1,725,552	(646,343)	268
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)	293,594
Net loss	$ (182,137)
Net unrealized loss on available-for-sale investments	(666)
Ending balance (in shares) at Sep. 30, 2021		142,439,829
Ending balance at Sep. 30, 2021	969,942	$ 142	1,798,678	(828,480)	(398)
Beginning balance (in shares) at Mar. 31, 2021		141,470,075
Beginning balance at Mar. 31, 2021	1,069,779	$ 141	1,749,097	(679,358)	(101)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)		650,656
Issuance of common stock upon exercise of stock options and vesting of RSUs	3,214	$ 1	3,213
Vesting of early exercised common stock	854		854
Stock-based compensation	21,134		21,134
Employee stock purchase plan	0
Net loss	(70,936)			(70,936)
Net unrealized loss on available-for-sale investments	(233)				(233)
Ending balance (in shares) at Jun. 30, 2021		142,120,731
Ending balance at Jun. 30, 2021	1,023,812	$ 142	1,774,298	(750,294)	(334)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)		229,918
Issuance of common stock upon exercise of stock options and vesting of RSUs	750		750
Vesting of early exercised common stock	1,142		1,142
Stock-based compensation	20,856		20,856
Employee stock purchase plan (in shares)		89,180
Employee stock purchase plan	1,632		1,632
Net loss	(78,186)			(78,186)
Net unrealized loss on available-for-sale investments	(64)				(64)
Ending balance (in shares) at Sep. 30, 2021		142,439,829
Ending balance at Sep. 30, 2021	$ 969,942	$ 142	1,798,678	(828,480)	(398)
Beginning balance (in shares) at Dec. 31, 2021	142,623,065	142,623,065
Beginning balance at Dec. 31, 2021	$ 916,406	$ 142	1,822,179	(903,348)	(2,567)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)		715,961
Issuance of common stock upon exercise of stock options and vesting of RSUs	283	$ 1	282
Vesting of early exercised common stock	1,228		1,228
Stock-based compensation	22,315		22,315
Employee stock purchase plan (in shares)		230,876
Employee stock purchase plan	1,530		1,530
Net loss	(79,850)			(79,850)
Net unrealized loss on available-for-sale investments	(6,682)				(6,682)
Ending balance (in shares) at Mar. 31, 2022		143,569,902
Ending balance at Mar. 31, 2022	$ 855,230	$ 143	1,847,534	(983,198)	(9,249)
Beginning balance (in shares) at Dec. 31, 2021	142,623,065	142,623,065
Beginning balance at Dec. 31, 2021	$ 916,406	$ 142	1,822,179	(903,348)	(2,567)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)	0
Net loss	$ (237,785)
Net unrealized loss on available-for-sale investments	$ (10,391)
Ending balance (in shares) at Sep. 30, 2022	144,031,588	144,031,588
Ending balance at Sep. 30, 2022	$ 739,961	$ 144	1,893,908	(1,141,133)	(12,958)
Beginning balance (in shares) at Mar. 31, 2022		143,569,902
Beginning balance at Mar. 31, 2022	855,230	$ 143	1,847,534	(983,198)	(9,249)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)		153,269
Issuance of common stock upon exercise of stock options and vesting of RSUs	25	$ 1	24
Vesting of early exercised common stock	813		813
Stock-based compensation	22,891		22,891
Employee stock purchase plan	0
Net loss	(74,787)			(74,787)
Net unrealized loss on available-for-sale investments	(2,223)				(2,223)
Ending balance (in shares) at Jun. 30, 2022		143,723,171
Ending balance at Jun. 30, 2022	801,949	$ 144	1,871,262	(1,057,985)	(11,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares)		177,678
Issuance of common stock upon exercise of stock options and vesting of RSUs	135		135
Vesting of early exercised common stock	432		432
Stock-based compensation	21,148		21,148
Employee stock purchase plan (in shares)		130,739
Employee stock purchase plan	931		931
Net loss	(83,148)			(83,148)
Net unrealized loss on available-for-sale investments	$ (1,486)				(1,486)
Ending balance (in shares) at Sep. 30, 2022	144,031,588	144,031,588
Ending balance at Sep. 30, 2022	$ 739,961	$ 144	$ 1,893,908	$ (1,141,133)	$ (12,958)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss	$ (237,785)	$ (182,137)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	66,354	58,782
Depreciation and amortization	11,227	6,212
Net amortization/accretion on investment securities	2,735	5,361
Non-cash rent expense	2,193	2,622
Share of loss from equity method investment	3,959	1,766
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(2,811)	(2,153)
Other long-term assets	(3,211)	(991)
Accounts payable	1,930	1,277
Accrued and other current liabilities	(1,388)	6,420
Deferred revenue	466	(38,627)
Other long-term liabilities	(2,092)	2,092
Net cash used in operating activities	(158,423)	(139,376)
Cash flows from investing activities:
Purchases of property and equipment	(3,499)	(20,710)
Purchase of stock in equity method investment	0	(15,938)
Proceeds from maturities of investments	260,379	645,854
Purchase of investments	(200,318)	(474,801)
Net cash provided by investing activities	56,562	134,405
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options	443	8,024
Proceeds from issuance of common stock under the employee stock purchase plan	2,461	3,617
Net cash provided by financing activities	2,904	11,641
Net change in cash, cash equivalents and restricted cash	(98,957)	6,670
Cash, cash equivalents and restricted cash — beginning of period	183,606	192,800
Cash, cash equivalents and restricted cash — end of period	84,649	199,470
Non-cash investing activities:
Right-of-use asset obtained in exchange for lease liability	31,361	0
Supplemental disclosure:
Cash paid for amounts included in the measurement of lease liabilities	(6,605)	(4,058)
Cash received for amounts related to tenant improvement allowances	$ 325	$ 1,111

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Allogene Therapeutics, Inc. (the Company or Allogene) was incorporated on November 30, 2017 in the State of Delaware and is headquartered in South San Francisco, California. Allogene is an immuno-oncology company pioneering the development and commercialization of genetically engineered allogeneic T cell therapies for the treatment of cancer. The Company is developing a pipeline of off-the-shelf T cell product candidates that are designed to target and kill cancer cells. Need for Additional Capital The Company has sustained operating losses and expects to continue to generate operating losses for the foreseeable future. The Company’s ultimate success depends on the outcome of its research and development activities as well as the ability to commercialize the Company's product candidates. The Company had cash and cash equivalents and investments of $637.3 million as of September 30, 2022. Since inception through September 30, 2022, the Company has incurred cumulative net losses of $1.1 billion. 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 to fully implement its business plan. The Company intends to raise additional capital through the issuance of equity securities, debt financings or other sources in order to further implement its business plan. However, if such financing is not available when needed and at adequate levels, the Company will need to reevaluate its operating plan and may be required to delay the development of its product candidates. The Company expects that its cash and cash equivalents and investments will be sufficient to fund its operations for a period of at least one year from the date the accompanying unaudited condensed consolidated financial statements are filed with the Securities and Exchange Commission (SEC).

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated 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 SEC. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the Company’s opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of the results of operations and cash flows for the periods presented have been included. The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All material intercompany balances and transactions have been eliminated during consolidation. The condensed consolidated balance sheet as of September 30, 2022, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed consolidated statements of stockholders’ equity as of September 30, 2022 and 2021, the condensed consolidated 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 consolidated financial statements are unaudited. The results of operations for the three and nine months ended September 30, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, or for any other future annual or interim period. These condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and related notes for the year ended December 31, 2021, included in the Company’s Annual Report on Form 10-K filed with the SEC on February 23, 2022. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions made in the accompanying condensed consolidated financial statements include but are not limited to the fair value of stock options, fair value of investments, income tax uncertainties, and certain accruals. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates. Significant Accounting Policies There have been no significant changes to the accounting policies during the three and nine months ended September 30, 2022, as compared to the significant accounting policies described in Note 1 of the “Notes to Financial Statements” in the Company’s audited financial statements included in its Annual Report. Recently Adopted Accounting Pronouncements There have been no new accounting pronouncements issued or effective that are expected to have a material impact on the Company's condensed financial statements. Recent Accounting Pronouncements Not Yet Adopted The Company continues to monitor new accounting pronouncements issued by the FASB and does not believe any accounting pronouncements issued through the date of this report will have a material impact on the Company's condensed consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company measures and reports its cash equivalents, restricted cash, 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 are measured at fair value based on inputs including quoted prices that are derived from observable market data and are classified as Level 2 inputs, except for investments in U.S. treasury securities which are classified as Level 1. There were no Level 3 assets or liabilities as of September 30, 2022 and as of December 31, 2021. Financial assets 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 as of December 31, 2021 are presented in the following tables: September 30, 2022 Level 1 Level 2 Level 3 Fair Value (In thousands) Financial Assets: Money market funds (1) $ 19,225 $ — $ — $ 19,225 Commercial paper — 17,987 — 17,987 Corporate bonds — 168,517 — 168,517 U.S. treasury securities 332,334 — — 332,334 U.S. agency securities — 44,142 — 44,142 Total financial assets $ 351,559 $ 230,646 $ — $ 582,205 December 31, 2021 Level 1 Level 2 Level 3 Fair Value (In thousands) Financial Assets: Money market funds (1) $ 115,867 $ — $ — $ 115,867 Commercial paper — 58,976 — 58,976 Corporate bonds — 223,474 — 223,474 U.S. treasury securities 303,016 — — 303,016 U.S. agency securities — 50,701 — 50,701 Total financial assets $ 418,883 $ 333,151 $ — $ 752,034 (1) Included within cash and cash equivalents on the Company’s condensed consolidated balance sheets

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2022
Investments, All Other Investments [Abstract]
Financial Instruments	Financial InstrumentsThe fair value and amortized cost of cash equivalents and available-for-sale securities by major security type as of September 30, 2022 and as of December 31, 2021 are presented in the following tables: September 30, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (In thousands) Money market funds $ 19,225 $ — $ — $ 19,225 Commercial paper 17,995 — (8) 17,987 Corporate bonds 172,278 — (3,761) 168,517 U.S. treasury securities 339,145 1 (6,812) 332,334 U.S. agency securities 46,076 — (1,934) 44,142 Total cash equivalents and investments $ 594,719 $ 1 $ (12,515) $ 582,205 Classified as: Cash equivalents $ 19,225 Short-term investments 477,872 Long-term investments 85,108 Total cash equivalents and investments $ 582,205 December 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (In thousands) Money market funds $ 115,867 $ — $ — $ 115,867 Commercial paper 58,981 2 (7) 58,976 Corporate bonds 224,092 29 (647) 223,474 U.S. treasury securities 304,142 2 (1,128) 303,016 U.S. agency securities 51,075 — (374) 50,701 Total cash equivalents and investments $ 754,157 $ 33 $ (2,156) $ 752,034 Classified as: Cash equivalents $ 115,867 Short-term investments 283,988 Long-term investments 352,179 Total cash equivalents and investments $ 752,034 As of September 30, 2022, the remaining contractual maturities of available-for-sale securities were less than 2 years. There have been no significant realized losses on available-for-sale securities for the periods presented. As of September 30, 2022, unrealized losses on available-for-sale securities are not attributed to credit risk. 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. As of September 30, 2022 and December 31, 2021, securities with a fair value of $153.7 million and zero, respectively, were in a continuous net unrealized loss position for more than 12 months. To date, the Company has not recorded any impairment charges on available-for-sale securities. As of September 30, 2022 and December 31, 2021, the Company recognized $1.5 million and $1.9 million, respectively, of accrued interest receivable from available-for-sale securities within prepaid expenses and other current assets on the consolidated balance sheets.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet ComponentsProperty and Equipment, Net Property and Equipment consist of the following: September 30, December 31, (In thousands) Leasehold improvements $ 108,412 $ 108,353 Laboratory equipment 31,443 29,666 Computer equipment and purchased software 5,033 4,373 Furniture and fixtures 3,976 3,920 Construction in progress 166 39 Total 149,030 146,351 Less: accumulated depreciation (34,588) (23,361) Total property and equipment, net $ 114,442 $ 122,990

License and Collaboration Agree

License and Collaboration Agreements	9 Months Ended
	Sep. 30, 2022
Research and Development [Abstract]
License and Collaboration Agreements	License and Collaboration Agreements Asset Contribution Agreement with Pfizer In April 2018, the Company entered into an Asset Contribution Agreement (the Pfizer Agreement) with Pfizer pursuant to which the Company acquired certain assets, including certain contracts and intellectual property for the development and administration of chimeric antigen receptor (CAR) T cells for the treatment of cancer. The Company is required to make milestone payments upon successful completion of regulatory and sales milestones on a target-by-target basis for the targets, including CD19 and B-cell maturation antigen (BCMA), covered by the Pfizer Agreement. The aggregate potential milestone payments upon successful completion of various regulatory milestones in the United States and the European Union are $30.0 million or $60.0 million, depending on the target, with aggregate potential regulatory and development milestones of up to $840.0 million, provided that the Company is not obligated to pay a milestone for regulatory approval in the European Union for an anti-CD19 allogeneic CAR T cell product, to the extent Servier has commercial rights to such territory. The aggregate potential milestone payments upon reaching certain annual net sales thresholds in North America, Europe, Asia, Australia and Oceania (the Territory) for a certain number of targets covered by the Pfizer Agreement are $325.0 million per target. The sales milestones in the foregoing sentence are payable on a country-by-country basis until the last to expire of any Pfizer Royalty Term, as described below, for any product in such country in the Territory. In October 2019, the Territory was expanded to all countries in the world. No milestone or royalty payments were made in the three and nine months ended September 30, 2022 or 2021. Pfizer is also eligible to receive, on a product-by-product and country-by-country basis, royalties in single-digit percentages on annual net sales for products covered by the Pfizer Agreement or that use certain Pfizer intellectual property and for which an investigational new drug application (IND) is first filed on or before April 6, 2023. The Company’s royalty obligation with respect to a given product in a given country begins upon the first sale of such product in such country and ends on the later of (i) expiration of the last claim of any applicable patent or (ii) 12 years from the first sale of such product in such country. Research Collaboration and License Agreement with Cellectis As part of the Pfizer Agreement, Pfizer assigned to the Company a Research Collaboration and License Agreement (the Original Cellectis Agreement) with Cellectis S.A. (Cellectis). On March 8, 2019, the Company entered into a License Agreement (the Cellectis Agreement) with Cellectis. In connection with the execution of the Cellectis Agreement, on March 8, 2019, the Company and Cellectis also entered into a letter agreement (the Letter Agreement), pursuant to which the Company and Cellectis agreed to terminate the Original Cellectis Agreement. The Original Cellectis Agreement included a research collaboration to conduct discovery and pre-clinical development activities to generate CAR T cells directed at targets selected by each party, which was completed in June 2018. Pursuant to the Cellectis Agreement, Cellectis granted to the Company an exclusive, worldwide, royalty-bearing license, on a target-by-target basis, with sublicensing rights under certain conditions, under certain of Cellectis’s intellectual property, including its TALEN and electroporation technology, to make, use, sell, import, and otherwise exploit and commercialize CAR T products directed at certain targets, including BCMA, FLT3, DLL3 and CD70 (the Allogene Targets), for human oncologic therapeutic, diagnostic, prophylactic and prognostic purposes. In addition, certain Cellectis intellectual property rights granted by Cellectis to the Company and to Servier pursuant to the Exclusive License and Collaboration Agreement by and between Servier and Pfizer, dated October 30, 2016, which Pfizer assigned to the Company in April 2018, will survive the termination of the Original Cellectis Agreement. Pursuant to the Cellectis Agreement, the Company granted Cellectis a non-exclusive, worldwide, royalty-free, perpetual and irrevocable license, with sublicensing rights under certain conditions, under certain of the Company's intellectual property, to make, use, sell, import and otherwise commercialize CAR T products directed at certain targets (the Cellectis Targets). The Cellectis Agreement provides for development and sales milestone payments by the Company of up to $185.0 million per product that is directed against an Allogene Target, with aggregate potential development and sales milestone payments totaling up to $2.8 billion. Cellectis is also eligible to receive tiered royalties on annual worldwide net sales of any products that are commercialized by the Company that contain or incorporate, are made using or are claimed or covered by, Cellectis intellectual property licensed to the Company under the Cellectis Agreement (the Allogene Products), at rates in the high single-digit percentages. Such royalties may be reduced, on a licensed product-by-licensed product and country-by-country basis, for generic entry and for payments due under licenses of third party patents. Pursuant to the Cellectis Agreement, and subject to certain exceptions, the Company is required to indemnify Cellectis against all third party claims related to the development, manufacturing, commercialization or use of any Allogene Product or arising out of the Company’s material breach of the representations, warranties or covenants set forth in the Cellectis Agreement, and Cellectis is required, subject to certain exceptions, to indemnify the Company against all third party claims related to the development, manufacturing, commercialization or use of CAR T products directed at Cellectis Targets or arising out of Cellectis’s material breach of the representations, warranties or covenants set forth in the Cellectis Agreement. The royalties are payable, on a licensed-product-by-licensed-product and country-by-country basis, until the later of (i) the expiration of the last to expire of the licensed patents covering such product; (ii) the loss of regulatory exclusivity afforded such product in such country, and (iii) the tenth anniversary of the date of the first commercial sale of such product in such country; however, in no event shall such royalties be payable, with respect to a particular licensed product, past the twentieth anniversary of the first commercial sale for such product. Depending on the Cellectis Target, the Company has a right of first refusal or right of first negotiation to purchase or license from Cellectis rights to develop and commercialize products against such Cellectis Targets. Under the Cellectis Agreement, the Company has certain diligence obligations to progress the development of CAR T product candidates and to commercialize one CAR T product per Allogene Target in one major market country where the Company has received regulatory approval. If the Company materially breaches any of its diligence obligations and fails to cure within 90 days, then with respect to certain targets, such target will cease to be an Allogene Target and instead will become a Cellectis Target. Unless earlier terminated in accordance with its terms, the Cellectis Agreement will expire on a product-by-product and country-by-country basis, upon expiration of all royalty payment obligations with respect to such licensed product in such country. The Company has the right to terminate the Cellectis Agreement at will upon 60 days’ prior written notice, either in its entirety or on a target-by-target basis. Either party may terminate the Cellectis Agreement, in its entirety or on a target-by-target basis, upon 90 days’ prior written notice in the event of the other party’s uncured material breach. The Cellectis Agreement may also be terminated by the Company upon written notice at any time in the event that Cellectis becomes bankrupt or insolvent or upon written notice within 60 days of a consummation of a change of control of Cellectis. All costs the Company incurred in connection with this agreement were recognized as research and development expenses. For the three and nine months ended September 30, 2022, zero costs were incurred related to the achievement of a clinical development milestone under this agreement. For the three and nine months ended September 30, 2021, $5.0 million and $10.0 million, respectively, in costs were incurred related to the achievement of a clinical development milestone under this agreement. License and Collaboration Agreement with Servier As part of the Pfizer Agreement, Pfizer assigned to the Company an Exclusive License and Collaboration Agreement (the Servier Agreement), with Les Laboratoires Servier SAS and Institut de Recherches Internationales Servier SAS (collectively, Servier) to develop, manufacture and commercialize certain allogeneic anti-CD19 CAR T cell product candidates, including UCART19, in the United States with the option to obtain the rights over additional anti-CD19 product candidates and for allogeneic CAR T cell product candidates directed against one additional target. In October 2019, the Company agreed to waive its rights to the one additional target. Under the Servier Agreement, the Company has an exclusive license to develop, manufacture and commercialize UCART19, ALLO-501 and ALLO-501A in the field of anti-tumor adoptive immunotherapy in the United States, with an exclusive option to obtain the same rights for additional product candidates in the United States and, if Servier does not elect to pursue development or commercialization of those product candidates in certain markets outside of the United States pursuant to its license, outside of the United States as well. The Company is not required to make any additional payments to Servier to exercise an option. If the Company opts-in to another product candidate, Servier has the right to obtain rights to such product candidate outside the United States and to share development costs for such product candidate. Under the Servier Agreement, the Company is required to use commercially reasonable efforts to develop and obtain marketing approval in the United States in the field of anti-tumor adoptive immunotherapy for at least one product directed against CD19, and Servier is required to use commercially reasonable efforts to develop and obtain marketing approval in the European Union, and one other country in a group of specified countries outside of the European Union and the United States, in the field of anti-tumor adoptive immunotherapy for at least one allogeneic adaptive T cell product directed against a certain Company-selected target. For product candidates that the Company is co-developing with Servier, including UCART19, ALLO-501 and ALLO-501A, the Company is responsible for 60% of the specified development costs and Servier is responsible for the remaining 40% of the specified development costs under the applicable global research and development plan. Subject to certain restrictions, each party has the right to conduct activities that are specific to its territory outside the global research and development plan at such party’s sole expense. In addition, each party is solely responsible for commercialization activities in its territory at such party’s sole expense. The Company is required to make milestone payments to Servier upon successful completion of regulatory and sales milestones. The Servier Agreement provides for aggregate potential payments by the Company to Servier of up to $137.5 million upon successful completion of various regulatory milestones, and aggregate potential payments by the Company to Servier of up to $78.0 million upon successful completion of various sales milestones. Similarly, Servier is required to make milestone payments upon successful completion of regulatory and sales milestones for products directed at the Allogene-target covered by the Servier Agreement that achieves such milestones. The total potential payments that Servier is obligated to make to the Company under the Servier Agreement upon successful completion of regulatory and sales milestones are $42.0 million and €70.5 million ($69.1 million), respectively. The foregoing milestones are subject to certain adjustments if the Company obtains rights for certain products outside of the United States upon Servier’s election not to pursue such rights. Each party is also eligible to receive tiered royalties on annual net sales in countries within the paying party’s respective territory of any licensed products that are commercialized by such party that are directed at the targets licensed by such party under the Servier Agreement. The royalty rates are in a range from the low tens to the high teen percentages. Such royalties may be reduced for interchangeable drug entry, expiration of patent rights and amounts paid pursuant to licenses of third-party patents. The royalty obligation for each party with respect to a given licensed product in a given country in each party’s respective territory (the Servier Royalty Term) begins upon the first commercial sale of such product in such country and ends after a defined number of years. Unless earlier terminated in accordance with the Servier Agreement, the Servier Agreement will continue, on a licensed product-by-licensed product and country-by-country basis, until the Servier Royalty Term with respect to the sale of such licensed product in such country expires. For the three and nine months ended September 30, 2022, the Company recorded $3.8 million and $20.4 million, respectively, of net cost recoveries under the cost-sharing terms of the Servier Agreement as a reduction to research and development expenses. For the three and nine months ended September 30, 2021, the Company recorded $5.1 million and $13.2 million, respectively, of net cost recoveries. As of September 30, 2022 and December 31, 2021, amounts due from Servier of $4.3 million and $4.1 million, respectively, were recorded in other current assets in the accompanying condensed consolidated balance sheets. On September 15, 2022, Servier sent a notice of discontinuation (Discontinuation) of its involvement in the development of all licensed products directed against CD19, including UCART19, ALLO-501 and ALLO-501A (collectively, CD19 Products), pursuant to the Servier Agreement. Servier’s Discontinuation provides the Company with the right to elect a license to the CD19 Products outside of the United States (Ex-US Option) and does not otherwise affect the Company's current exclusive license for the development and commercialization of CD19 Products in the United States. Research Collaboration and License Agreement with Notch On November 1, 2019, the Company entered into a Collaboration and License Agreement (the Notch Agreement) with Notch Therapeutics Inc. (Notch), pursuant to which Notch granted to Allogene an exclusive, worldwide, royalty-bearing, sublicensable license under certain of Notch’s intellectual property to develop, make, use, sell, import, and otherwise commercialize therapeutic gene-edited T cell and/or natural killer (NK) cell products from induced pluripotent stem cells directed at certain CAR targets for initial application in non-Hodgkin lymphoma, acute lymphoblastic leukemia and multiple myeloma. In addition, Notch has granted Allogene an option to add certain specified targets to its exclusive license in exchange for an agreed per-target option fee. The Notch Agreement includes a research collaboration to conduct research and pre-clinical development activities to generate engineered cells directed to Allogene’s exclusive targets, which will be conducted in accordance with an agreed research plan and budget under the oversight of a joint development committee. Allogene will reimburse Notch’s costs incurred in accordance with such plan and budget. The term of the research collaboration will expire upon the earlier of (i) the fifth anniversary of the date of the Notch Agreement, (ii) at Allogene’s election, following the joint development committee’s determination that for each exclusive target, Notch has met certain success criteria, or (iii) the joint development committee’s determination that the research collaboration cannot be reasonably pursued against any exclusive target due to technical infeasibility or safety issues. In connection with the execution of the Notch Agreement, Allogene made an upfront payment to Notch of $10.0 million in return for a license to access Notch's technology in order to conduct research pursuant to the Notch Agreement. In addition, Allogene made a $5.0 million investment in Notch’s series seed convertible preferred stock, resulting in Allogene having a 25% ownership interest in Notch’s outstanding capital stock on a fully diluted basis immediately following the investment. In connection with this investment, an Allogene representative serves on the Notch Board of Directors. In February 2021, the Company made an additional $15.9 million investment in Notch's Series A preferred stock. In October 2021, the Company made an additional $1.8 million investment in Notch's common stock. Immediately following this transaction, the Company's share in Notch was 23.0% on a voting interest basis. The Company did not have a controlling interest in Notch as of September 30, 2022, and continued to account for its investment in Notch as an equity method investment. Under the Notch Agreement, Notch will be eligible to receive up to $7.25 million upon achieving certain agreed research milestones, up to $4.0 million per exclusive target upon achieving certain pre-clinical development milestones, and up to $283.0 million per exclusive target and cell type (i.e., T cell or NK cell) upon achieving certain clinical, regulatory and commercial milestones. Notch is also entitled to receive tiered royalties in the mid to high single digit range on Allogene’s sales of licensed products, subject to certain reductions, for a term, on a country-by-country and product-by-product basis, commencing on first commercial sale of such product in such country and continuing until the latest of (i) the date upon which there is no valid claim of the licensed patents in such country of sale that covers such product, (ii) the expiration of applicable data or other regulatory exclusivity in such country of sale or (iii) a defined period from the first commercial sale of such product in such country. The terms of the Notch Agreement will continue on a product-by-product and country-by-country basis until Allogene’s payment obligations with respect to such product in such country have expired. Following such expiration, Allogene’s license with respect to such product and country shall be perpetual, irrevocable, fully paid up and royalty-free. Allogene may terminate the Collaboration Agreement in whole or on a product-by-product basis upon ninety days’ prior written notice to Notch. Either party may also terminate the Collaboration Agreement with written notice upon material breach by the other party, if such breach has not been cured within a defined period of receiving such notice, or in the event of the other party’s insolvency. For the three and nine months ended September 30, 2022, the Company recorded $1.0 million and $2.8 million, respectively, in collaboration costs as research and development expenses. For the three and nine months ended September 30, 2021, the Company recorded $0.8 million and $3.9 million, respectively, in collaboration costs as research and development expenses. Strategic Alliance with The University of Texas MD Anderson Cancer Center On October 6, 2020, the Company entered into a strategic five-year collaboration agreement with The University of Texas MD Anderson Cancer Center (MD Anderson) for the preclinical and clinical investigation of allogeneic CAR T cell product candidates. The Company and MD Anderson are collaborating on the design and conduct of preclinical and clinical studies with oversight from a joint steering committee. Under the terms of the agreement, the Company has committed up to $15.0 million of funding for the duration of the agreement. Payment of this funding is contingent on mutual agreement to study orders in order for any study to be included under the alliance. The Company made an upfront payment of $3.0 million to MD Anderson in the year ended December 31, 2020. The Company is obligated to make further payments to MD Anderson each year upon the anniversary of the agreement effective date through the duration of the agreement term. These costs are expensed to research and development as MD Anderson renders the services under the strategic alliance. The agreement may be terminated by either party for material breach by the other party. Individual studies may be terminated for, among other things, material breach, health and safety concerns or where the institutional review board, the review board at the clinical site with oversight of the clinical study, requests termination of any study. Where any legal or regulatory authorization is finally withdrawn or terminated, the relevant study will also terminate automatically. For the three and nine months ended September 30, 2022, the Company recorded $0.2 million and $1.1 million in collaboration costs as research and development expenses. For the three and nine months ended September 30, 2021, the Company recorded $0.4 million and $0.8 million, respectively, in collaboration costs as research and development expenses. Joint Venture and License Agreement with Allogene Overland Biopharm (CY) Limited On December 14, 2020, the Company entered into a License Agreement with Allogene Overland Biopharm (CY) Limited (Allogene Overland), a joint venture established by the Company and Overland Pharmaceuticals (CY) Inc. (Overland), pursuant to a Share Purchase Agreement, dated December 14, 2020, for the purpose of developing, manufacturing and commercializing certain allogeneic CAR T cell therapies for patients in greater China, Taiwan, South Korea and Singapore (the JV Territory). Pursuant to the Share Purchase Agreement, the Company acquired Seed Preferred Shares in Allogene Overland representing 49% of Allogene Overland's outstanding stock as partial consideration for the License Agreement, and Overland acquired Seed Preferred Shares representing 51% of Allogene Overland's outstanding stock for $117.0 million in upfront and certain quarterly cash payments, to support operations of Allogene Overland. As of September 30, 2022, the Company and Overland are the sole equity holders in Allogene Overland. The Company received $40 million from Allogene Overland as partial consideration for the License Agreement. Pursuant to the License Agreement, the Company granted Allogene Overland an exclusive license to develop, manufacture and commercialize certain allogeneic CAR T cell candidates directed at four targets, BCMA, CD70, FLT3, and DLL3, in the JV Territory. As consideration, the Company would also be entitled to additional regulatory milestone payments of up to $40.0 million and, subject to certain conditions, tiered low-to-mid single-digit sales royalties. Subsequent to entering into the License Agreement, Allogene Overland assigned the License Agreement to a wholly-owned subsidiary, Allogene Overland BioPharm (HK) Limited. On April 1, 2022, Allogene Overland HK assigned the License Agreement to Allogene Overland Biopharm (PRC) Co., Limited. Promises that the Company concluded were distinct performance obligations in the License Agreement included: (1) the license of intellectual property and delivery of know-how, (2) the manufacturing license, related know-how and support, (3) if and when available know-how developed in future periods, and (4) participation in the joint steering committee. In order to determine the transaction price, the Company evaluated all the payments to be received during the duration of the contract. Fixed consideration exists in the form of the upfront payment. Regulatory milestones and royalties were considered variable consideration. The Company constrains the estimated variable consideration when it assesses it is probable that a significant reversal in the amount of cumulative revenue recognized may occur in future periods. Milestone fees were constrained and not included in the transaction price due to the uncertainties of research and development. The Company re-evaluates the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The shares of Series Seed Preferred Stock were accounted for as part of the Company’s joint venture and equity method accounting upon formation of the joint venture, and as such, were excluded from the transaction price. The Company determined that the initial transaction price consists of the upfront payment of $40.0 million. The allocation of the transaction price is performed based on standalone selling prices, which are based on estimated amounts that the Company would charge for a performance obligation if it were sold separately . The transaction price allocated to the license of intellectual property and delivery of know-how will be recognized upon grant of license and delivery of know-how. The transaction price allocated to (i) the manufacturing license, related know-how and support services, (ii) if and when available know-how developed in future periods, and (iii) participation in the joint steering committee, will be recognized over time as the services are delivered. Funds received in advance are recorded as deferred revenue and will be recognized as the performance obligations are satisfied. The Company has determined that Allogene Overland is a variable interest entity as of September 30, 2022 and December 31, 2021. The Company does not have the power to independently direct the activities which most significantly affect Allogene Overland's economic performance. Accordingly, the Company did not consolidate Allogene Overland because the Company determined that it was not the primary beneficiary. For the three and nine months ended September 30, 2022, the Company recognized less than $0.1 million and $0.2 million of collaboration revenue, respectively. For the three and nine months ended September 30, 2021, the Company recognized less than $0.1 million and $38.4 million, respectively, of collaboration revenue, primarily related to the license of intellectual property and delivery of the know-how performance obligation which was delivered in the first quarter of 2021. For the three and nine months ended September 30, 2022, the Company recorded $0.3 million and $0.6 million, respectively, of net cost recoveries under the terms of the license agreement as a reduction to research and development expenses. For the three and nine months ended September 30, 2021, the Company recorded zero net cost recoveries. Collaboration and License Agreement with Antion On January 5, 2022, the Company entered into an exclusive collaboration and global license agreement (Antion Collaboration and License Agreement) with Antion Biosciences SA (Antion) for Antion’s miRNA technology (miCAR), to advance multiplex gene silencing as an additional tool to develop next generation allogeneic CAR T products. Pursuant to the agreement, Antion will exclusively collaborate with the Company on oncology products for a defined period. The Company will also have exclusive worldwide rights to commercialize products incorporating Antion technology developed during the collaboration. The Antion Collaboration and License Agreement includes an exclusive research collaboration to conduct research and development of the use of Antion’s proprietary technologies to produce certain products for a defined period, which will be conducted in accordance with an agreed research plan and budget under the oversight of a joint steering committee. The Company will reimburse Antion's costs incurred in accordance with such plan and budget. In connection with the execution of the Antion Collaboration and License Agreement, the Company made an upfront payment to Antion of $3.5 million in return for a license to access Antion's technology in order to conduct research pursuant to the agreement. The upfront payment was fully recognized as research and development expense as the license had no foreseeable alternative future use. In addition, the Company made a $3.0 million investment in Antion's preferred stock and is expected to make an additional $3.0 million investment in Antion's preferred stock upon achievement of an agreed milestone. The Company accounts for its investment in Antion's preferred stock as an equity investment measured at cost less any impairment. In connection with this investment, a Company representative was appointed to Antion’s Board of Directors. Under the Antion Collaboration and License Agreement, Antion will be eligible to receive up to $35.3 million for four products upon achievement of certain development and regulatory milestones. For each additional product, Antion will be eligible to receive $2.0 million upon achievement of a regulatory milestone. Antion is also entitled to receive a low single-digit royalty on the Company’s sales of licensed products, subject to certain reductions. For the three and nine months ended September 30, 2022, the Company recorded $0.6 million and $4.5 million in research and development expenses related to the upfront payment and collaboration costs, of which $0.5 million is recorded in accrued and other liabilities as of September 30, 2022. The Company's total equity investment in Antion was $3.0 million as of September 30, 2022 and is recognized in other long-term assets in the condensed consolidated balance sheets.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases In August 2018, the Company entered into an operating lease agreement (HQ Lease) for office and laboratory space which consists of approximately 68,000 square feet located in South San Francisco, California. The lease term was 127 months beginning August 2018 through February 2029 with an option to extend the term for seven years which was not reasonably assured of exercise. The Company has made certain tenant improvements, including the addition of laboratory space, and has received $5.0 million of tenant improvement allowances. The rent payments began on March 1, 2019 after an abatement period. In December 2021, the Company amended its lease agreement to lease an additional 47,566 square feet of office and laboratory space in South San Francisco, California, as part of the same building as the Company’s current headquarters. The lease term commenced in April 2022 and is for a period of 120 months. The rent payments for the expansion premises began in August 2022 after an abatement period. The lease term for the existing premises was also extended and the lease for both the existing and expansion premises will expire on March 31, 2032 with an option to extend the term for eight years which is not reasonably assured of exercise. In October 2018, the Company entered into an operating lease agreement for office and laboratory space which consists of 14,943 square feet located in South San Francisco, California. The lease term was 124 months beginning November 2018 through February 2029, with an option to extend the term for another seven years which was not reasonably assured of exercise. The Company has made certain tenant improvements, including the upgrading of current office and laboratory space with a lease incentive allowance of $0.8 million. Rent payments began in November 2018. In December 2021, the Company amended its lease agreement to extend the term of the lease to be co-terminus with the HQ Lease. The lease term will expire March 31, 2032 with an option to extend the term for eight years which is not reasonably assured of exercise. In February 2019, the Company entered into a lease agreement for approximately 118,000 square feet of space to develop a cell therapy manufacturing facility in Newark, California. The lease term is 188 months beginning November 2020 through July 2036. Upon certain conditions, the Company has two ten-year options to extend the lease, both of which are not reasonably assured of exercise. The Company has received $3.0 million of tenant improvement allowances for costs related to the design and construction of certain Company improvements. The Company maintains letters of credit for the benefit of landlords which is disclosed as restricted cash in the condensed consolidated balance sheets. Restricted cash related to letters of credit due to landlords was $6.0 million as of September 30, 2022 and December 31, 2021. The balance sheet classification of our lease liabilities were as follows (in thousands): September 30, 2022 December 31, 2021 Operating lease liabilities Current portion included in accrued and other current liabilities $ 5,831 $ 3,200 Long-term portion of lease liabilities 96,706 69,929 Total operating lease liabilities $ 102,537 $ 73,129 The components of lease costs for operating leases, which were recognized in operating expenses, were as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2022 2021 2022 2021 Operating lease cost $ 3,177 $ 1,853 $ 8,476 $ 5,568 Variable lease cost 616 448 1,468 979 Total lease costs $ 3,793 $ 2,301 $ 9,944 $ 6,547 Cash paid for amounts included in the measurement of lease liabilities for the nine months ended September 30, 2022 was $2.6 million and was included in net cash used in operating activities in our condensed consolidated statements of cash flows. The undiscounted future lease payments under the lease agreements as of September 30, 2022 were as follows: Year ending December 31: (In thousands) 2022 (remaining 6 months) $ 2,943 2023 12,065 2024 12,464 2025 12,636 2026 12,819 2027 and thereafter 90,492 Total undiscounted lease payments 143,419 Less: Present value adjustment (40,882) Total $ 102,537 Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, we use our estimated incremental borrowing rate. The weighted average discount rate used to determine the operating lease liability was 6.19%. As of September 30, 2022, the weighted average remaining lease term for our operating leases is 10.21 years. Other Commitments In July 2020, the Company entered into a Solar Power Purchase and Energy Services Agreement for the installation and operation of a solar photovoltaic generating system and battery energy storage system at the Company's cell therapy manufacturing facility in Newark, California. The agreement has a term of 20 years and commenced in September 2022. The Company is obligated to pay for electricity generated from the system at an agreed rate for the duration of the agreement term. Termination of the agreement by the Company will result in a termination payment due of approximately $4.3 million. In connection with the agreement, the Company maintains a letter of credit for the benefit of the service provider in the amount of $4.3 million which is disclosed as restricted cash in the condensed consolidated balance sheets as of September 30, 2022. The Company has entered into certain license agreements for intellectual property which is used as part of our development and manufacturing processes. Each of these respective agreements are generally cancellable by the Company. These agreements require payment of annual license fees and may include conditional milestone payments for achievement of specific research, clinical and commercial events, and royalty payments. The timing and likelihood of any significant conditional milestone payments or royalty payments becoming due was not probable as of September 30, 2022. The Company enters into contracts in the normal course of business that includes arrangements with clinical research organizations, vendors for preclinical research and vendors for manufacturing. These agreements generally allow for cancellation with notice. As of September 30, 2022, the Company had non-cancellable purchase commitments of $0.4 million.

Equity Method Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 2022
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment	Equity Method Investments Notch Therapeutics In conjunction with the execution of the Notch Agreement (see Note 6), the Company also entered into a Share Purchase Agreement with the Company acquiring shares of Notch’s Series Seed convertible preferred stock for a total investment cost of $5.1 million which includes transaction costs of $0.1 million, resulting in a 25% ownership interest in Notch. In February 2021, the Company made a $15.9 million investment in Notch's Series A preferred stock. Immediately following this transaction, the Company's share in Notch was 20.7% on a voting interest basis. In October 2021, the Company made an additional $1.8 million investment in Notch's common stock. Immediately following this transaction, the Company's share in Notch was 23.0% on a voting interest basis. The Company’s total equity investment in Notch as of September 30, 2022 and December 31, 2021 was $14.0 million and $18.0 million, respectively, and the Company accounted for the investment using the equity method of accounting. During the three and nine months ended September 30, 2022 and 2021, the Company recognized its share of Notch's net loss under the other expenses caption within the condensed consolidated statement of operations. Allogene Overland In conjunction with the execution of the License Agreement with Allogene Overland (see Note 6), the Company also entered into a Share Purchase Agreement and Shareholders' Agreement with the joint venture company acquiring shares of Allogene Overland’s Seed Preferred Shares representing a 49% ownership interest in exchange for entering into a License Agreement which had a carrying value of zero. The Company accounts for its investment in Allogene Overland as an equity method investment at carrying value. The Company's total equity investment in Allogene Overland was zero as of September 30, 2022 and December 31, 2021. The Company’s equity investment in Allogene Overland as of September 30, 2022 and December 31, 2021 had a zero carryover basis. Therefore, the Company did not account for its share of losses incurred by Allogene Overland. See Note 6 for further details.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation In June 2018, the Company adopted its 2018 Equity Incentive Plan (Prior 2018 Plan). The Prior 2018 Plan provided for the Company to sell or issue common stock or restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the Company’s Board of Directors and consultants of the Company under terms and provisions established by the Company’s Board of Directors. In September 2018, the Board of Directors adopted a new amended and restated 2018 Equity Incentive Plan as a successor to and continuation of the Prior 2018 Plan, which became effective in October 2018 (the 2018 Plan), which authorized additional shares for issuance and provided for an automatic annual increase to the number of shares issuable under the 2018 Plan by an amount equal to 5% of the total number of shares of common stock outstanding on December 31st of the preceding calendar year. The term of any stock option granted under the 2018 Plan cannot exceed 10 years. The Company generally grants stock-based awards with service conditions only. 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. Options granted typically vest over a four-year period but may be granted with different vesting terms. Restricted Stock Units granted typically vest annually over a four-year period but may be granted with different vesting terms. As of September 30, 2022, there were 12,035,820 shares reserved by the Company under the 2018 Plan for the future issuance of equity awards. Stock Option Exchange program On June 21, 2022, the Company commenced an offer to exchange certain eligible options held by eligible employees of the Company for new options (the Exchange Offer). The Exchange Offer expired on July 19, 2022. Pursuant to the Exchange Offer, 199 eligible holders elected to exchange, and the Company accepted for cancellation, eligible options to purchase an aggregate of 3,666,600 shares of the Company’s common stock, representing approximately 93.5% of the total shares of common stock underlying the eligible options. On July 19, 2022, immediately following the expiration of the Exchange Offer, the Company granted new options to purchase 3,666,600 shares of common stock, pursuant to the terms of the Exchange Offer and the 2018 Plan. The exercise price of the new options granted pursuant to the Exchange Offer was $13.31 per share, which was the closing price of the common stock on the Nasdaq Global Select Market on the grant date of the new options. The new options are subject to a new three-year vesting schedule, vesting in equal annual installments over the vesting term. Each new option has a maximum term of seven years. The exchange of stock options was treated as a modification for accounting purposes. The incremental expense of $5.2 million for the new options was calculated using a lattice option pricing model. The incremental expense and the unamortized expense remaining on the exchanged options as of the modification date will be recognized over the new three-year service period. Stock Option Activity The following summarizes option activity under the 2018 Plan: Outstanding Options Number of Options Weighted- Average Exercise Price Weighted- Aggregate Intrinsic Value (in years) (in thousands) Balance, December 31, 2021 10,239,167 $ 21.10 7.68 $ 26,223 Granted 8,627,428 9.64 Exercised (174,451) 2.33 Forfeited (569,697) 24.41 Cancelled under the Option Exchange (3,666,600) 26.82 Granted under the Option Exchange 3,666,600 13.31 Balance, September 30, 2022 18,122,447 $ 12.99 8.05 $ 25,996 Exercisable, September 30, 2022 13,657,219 $ 13.04 8.29 $ 24,715 Vested and expected to vest, September 30, 2022 18,122,447 $ 12.99 8.05 $ 25,996 The aggregate intrinsic values of options outstanding, exercisable, vested and expected to vest were 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. For the nine months ended September 30, 2022, the estimated weighted-average grant-date fair value of employee options granted was $9.99 per share. As of September 30, 2022, there was $96.7 million of unrecognized stock-based compensation related to unvested stock options, which is expected to be recognized over a weighted-average period of 2 years, 324 days. The fair value of employee, consultant and director stock option awards was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions: Nine Months Ended September 30, 2022 2021 Expected term in years 5.25 - 6.08 5.27 - 6.08 Expected volatility 70.82% - 73.39% 69.73% - 70.80% Expected risk-free interest rate 1.61% - 3.49% 0.60% - 1.16% Expected dividend 0% 0% The fair value of the new options granted under the Option Exchange program was estimated at the date of grant using a lattice option pricing model with the following assumptions: expected volatility of 73.74%, expected risk-free rate of 3.06%, expected dividends of 0% and expected exercise barrier of 2.57. Expected term — The expected term represents the period that stock-based awards are expected to be outstanding. The expected term for option grants is determined using the simplified method. The simplified method deems the term to be the average of the time-to-vesting and the contractual life of the stock-based awards. Expected volatility — The Company uses an average historical stock price volatility of comparable public companies within the biotechnology and pharmaceutical industry that were deemed to be representative of future stock price trends as the Company does not have sufficient trading history for its common stock. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Risk-free interest rate —The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of option. Expected dividend —The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. Expected exercise barrier - The modified options are assumed to be exercised upon vesting and when the ratio of stock market price to exercise price reaches 2.57, or expiration, whichever is earlier. Restricted Stock Unit Activity The following summarizes restricted stock unit activity under the 2018 Plan: Outstanding Restricted Stock Units Restricted Stock Units Weighted- Weighted Average Remaining Vesting Life Aggregate Intrinsic Value (in years) (in thousands) Unvested December 31, 2021 4,261,108 $ 26.37 1.72 $ 63,576 Granted 3,316,499 9.74 1.89 Vested (991,967) 27.90 Forfeited (476,970) 22.24 Unvested September 30, 2022 6,108,670 $ 17.41 1.70 $ 65,974 Vested and expected to vest, September 30, 2022 6,108,670 $ 17.41 1.70 $ 65,974 As of September 30, 2022, there was $85.0 million of unrecognized stock-based compensation related to unvested restricted stock units, which is expected to be recognized over a weighted-average period of 2 years, 240 days. Total stock-based compensation related to stock options, restricted stock units, employee stock purchase plan and vesting of the founders’ common stock was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 11,016 $ 10,074 $ 35,068 $ 28,494 General and administrative 10,132 10,782 31,286 30,288 Total stock-based compensation $ 21,148 $ 20,856 $ 66,354 $ 58,782 Early Exercised Options The Company allows certain of its employees and its directors to exercise options granted under the Prior 2018 Plan and the 2018 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 Company’s 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 proceeds are initially recorded in accrued and other liabilities for the current portion, and other long-term liabilities for the non-current portion. The proceeds are reclassified to paid-in capital as the repurchase right lapses. During the nine months ended September 30, 2022 and 2021, zero and 293,594 options were early exercised. As of September 30, 2022 and December 31, 2021 there was $1.9 million and $2.9 million, respectively, recorded in accrued and other liabilities and $1.1 million and $2.5 million, respectively, recorded in other long-term liabilities related to shares held by employees and directors that were subject to repurchase. The underlying shares are shown as outstanding in the condensed consolidated financial statements since the exercise date but the shares which are subject to future vesting conditions are not included in the calculation of earnings per share.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Collaboration Revenue In December 2020, the Company entered into a license agreement with Allogene Overland, a corporate joint venture entity and related party (see Note 6). The license agreement was subsequently assigned to a wholly-owned subsidiary of Allogene Overland, Allogene Overland BioPharm (HK) Limited. On April 1, 2022, Allogene Overland HK assigned the License Agreement to Allogene Overland Biopharm (PRC) Co., Limited. During the three and nine months ended September 30, 2022, the Company recognized less than $0.1 million and $0.2 million of collaboration revenue under this arrangement, respectively. During the three and nine months ended September 30, 2021, the Company recognized less than $0.1 million and $38.4 million, respectively, of collaboration revenue under this arrangement. For the three and nine months ended September 30, 2022, the Company recorded $0.3 million and $0.6 million, respectively, of net cost recoveries under the terms of the license agreement as a reduction to research and development expenses. For the three and nine months ended September 30, 2021, the Company recorded zero net cost recoveries under the terms of the license agreement. Sublease Agreement In December 2018, the Company entered into a sublease with Bellco Capital LLC (Bellco) for 1,293 square feet of office space in Los Angeles, California for a three year term. On April 1, 2020, Bellco Capital Advisors Inc. assumed all rights, title, interests and obligations under the sublease from Bellco Capital LLC. In November 2021, the sublease was extended to June 30, 2025. The sublease was amended, effective in July 2022, to move to a nearby location, with office space of 737 square feet. The Company’s executive chairman, Arie Belldegrun, M.D., FACS, is a trustee of the Belldegrun Family Trust, which controls Bellco Capital Advisors Inc. The total right of use asset and associated liability recorded related to this related party lease was $0.2 million and $0.3 million at September 30, 2022 and December 31, 2021, respectively. Consulting Agreements In June 2018, the Company entered into a services agreement with Two River, LLC (Two River), a firm affiliated with the Company’s President and Chief Executive Officer, the Company’s Executive Chair of the board of directors, and a director of the Company to provide various managerial, clinical development, administrative, accounting and financial services to the Company. The costs incurred for services provided under this agreement were $0.1 million and $0.6 million for the three and nine months ended September 30, 2022, respectively. The costs incurred for services provided under this agreement were $0.2 million and $0.4 million for the three and nine months ended September 30, 2021, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe Company has a history of losses and expects to record a loss in 2022. The Company continues to maintain a full valuation allowance against its net deferred tax assets.

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 outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the period presented due to their anti-dilutive effect: September 30, 2022 2021 Stock options to purchase common stock 18,122,447 10,109,169 Restricted stock units subject to vesting 6,108,670 3,393,604 Expected shares to be purchased under Employee Stock Purchase Plan 750,317 276,253 Founders' shares of common stock subject to future vesting — 3,028,848 Early exercised stock options subject to future vesting 162,532 1,057,793 Total 25,143,966 17,865,667

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn October 6, 2022, the Company announced the initiation of the Phase 2 clinical trial of ALLO-501A (the ALPHA2 trial) in patients with relapsed/refractory large B-cell lymphoma. The Company is also in the process of initiating the EXPAND trial, which is intended to demonstrate the contribution of ALLO-647 to the lymphodepletion regimen. In accordance with the Servier Agreement, the Company is required to make a milestone payment of $8.0 million upon first dosing of the first patient in a Phase 2 clinical trial. The milestone payment is expected to be recognized in the fourth quarter.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated 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 SEC. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the Company’s opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of the results of operations and cash flows for the periods presented have been included. The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All material intercompany balances and transactions have been eliminated during consolidation. The condensed consolidated balance sheet as of September 30, 2022, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed consolidated statements of stockholders’ equity as of September 30, 2022 and 2021, the condensed consolidated 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 consolidated financial statements are unaudited. The results of operations for the three and nine months ended September 30, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, or for any other future annual or interim period. These condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and related notes for the year ended December 31, 2021, included in the Company’s Annual Report on Form 10-K filed with the SEC on February 23, 2022.
Use of Estimates	Use of EstimatesThe preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions made in the accompanying condensed consolidated financial statements include but are not limited to the fair value of stock options, fair value of investments, income tax uncertainties, and certain accruals. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.
Significant Accounting Policies	Significant Accounting Policies There have been no significant changes to the accounting policies during the three and nine months ended September 30, 2022, as compared to the significant accounting policies described in Note 1 of the “Notes to Financial Statements” in the Company’s audited financial statements included in its Annual Report.
Recently Adopted Accounting Pronouncements and Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements There have been no new accounting pronouncements issued or effective that are expected to have a material impact on the Company's condensed financial statements. Recent Accounting Pronouncements Not Yet Adopted The Company continues to monitor new accounting pronouncements issued by the FASB and does not believe any accounting pronouncements issued through the date of this report will have a material impact on the Company's condensed consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis and Level of Inputs Used in Such Measurements by Major Security Type	Financial assets 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 as of December 31, 2021 are presented in the following tables: September 30, 2022 Level 1 Level 2 Level 3 Fair Value (In thousands) Financial Assets: Money market funds (1) $ 19,225 $ — $ — $ 19,225 Commercial paper — 17,987 — 17,987 Corporate bonds — 168,517 — 168,517 U.S. treasury securities 332,334 — — 332,334 U.S. agency securities — 44,142 — 44,142 Total financial assets $ 351,559 $ 230,646 $ — $ 582,205 December 31, 2021 Level 1 Level 2 Level 3 Fair Value (In thousands) Financial Assets: Money market funds (1) $ 115,867 $ — $ — $ 115,867 Commercial paper — 58,976 — 58,976 Corporate bonds — 223,474 — 223,474 U.S. treasury securities 303,016 — — 303,016 U.S. agency securities — 50,701 — 50,701 Total financial assets $ 418,883 $ 333,151 $ — $ 752,034 (1) Included within cash and cash equivalents on the Company’s condensed consolidated balance sheets

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2022
Investments, All Other Investments [Abstract]
Schedule of Fair Value and Amortized Cost	The fair value and amortized cost of cash equivalents and available-for-sale securities by major security type as of September 30, 2022 and as of December 31, 2021 are presented in the following tables: September 30, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (In thousands) Money market funds $ 19,225 $ — $ — $ 19,225 Commercial paper 17,995 — (8) 17,987 Corporate bonds 172,278 — (3,761) 168,517 U.S. treasury securities 339,145 1 (6,812) 332,334 U.S. agency securities 46,076 — (1,934) 44,142 Total cash equivalents and investments $ 594,719 $ 1 $ (12,515) $ 582,205 Classified as: Cash equivalents $ 19,225 Short-term investments 477,872 Long-term investments 85,108 Total cash equivalents and investments $ 582,205 December 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (In thousands) Money market funds $ 115,867 $ — $ — $ 115,867 Commercial paper 58,981 2 (7) 58,976 Corporate bonds 224,092 29 (647) 223,474 U.S. treasury securities 304,142 2 (1,128) 303,016 U.S. agency securities 51,075 — (374) 50,701 Total cash equivalents and investments $ 754,157 $ 33 $ (2,156) $ 752,034 Classified as: Cash equivalents $ 115,867 Short-term investments 283,988 Long-term investments 352,179 Total cash equivalents and investments $ 752,034

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property and Equipment	Property and Equipment consist of the following: September 30, December 31, (In thousands) Leasehold improvements $ 108,412 $ 108,353 Laboratory equipment 31,443 29,666 Computer equipment and purchased software 5,033 4,373 Furniture and fixtures 3,976 3,920 Construction in progress 166 39 Total 149,030 146,351 Less: accumulated depreciation (34,588) (23,361) Total property and equipment, net $ 114,442 $ 122,990

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Lease Liabilities	The balance sheet classification of our lease liabilities were as follows (in thousands): September 30, 2022 December 31, 2021 Operating lease liabilities Current portion included in accrued and other current liabilities $ 5,831 $ 3,200 Long-term portion of lease liabilities 96,706 69,929 Total operating lease liabilities $ 102,537 $ 73,129
Schedule of Lease Costs	The components of lease costs for operating leases, which were recognized in operating expenses, were as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2022 2021 2022 2021 Operating lease cost $ 3,177 $ 1,853 $ 8,476 $ 5,568 Variable lease cost 616 448 1,468 979 Total lease costs $ 3,793 $ 2,301 $ 9,944 $ 6,547
Summary of Future Lease Payments Under Lease Liability	The undiscounted future lease payments under the lease agreements as of September 30, 2022 were as follows: Year ending December 31: (In thousands) 2022 (remaining 6 months) $ 2,943 2023 12,065 2024 12,464 2025 12,636 2026 12,819 2027 and thereafter 90,492 Total undiscounted lease payments 143,419 Less: Present value adjustment (40,882) Total $ 102,537

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity Under Plan	The following summarizes option activity under the 2018 Plan: Outstanding Options Number of Options Weighted- Average Exercise Price Weighted- Aggregate Intrinsic Value (in years) (in thousands) Balance, December 31, 2021 10,239,167 $ 21.10 7.68 $ 26,223 Granted 8,627,428 9.64 Exercised (174,451) 2.33 Forfeited (569,697) 24.41 Cancelled under the Option Exchange (3,666,600) 26.82 Granted under the Option Exchange 3,666,600 13.31 Balance, September 30, 2022 18,122,447 $ 12.99 8.05 $ 25,996 Exercisable, September 30, 2022 13,657,219 $ 13.04 8.29 $ 24,715 Vested and expected to vest, September 30, 2022 18,122,447 $ 12.99 8.05 $ 25,996
Schedule Stock Option Valuation Assumptions	The fair value of employee, consultant and director stock option awards was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions: Nine Months Ended September 30, 2022 2021 Expected term in years 5.25 - 6.08 5.27 - 6.08 Expected volatility 70.82% - 73.39% 69.73% - 70.80% Expected risk-free interest rate 1.61% - 3.49% 0.60% - 1.16% Expected dividend 0% 0%
Schedule of Restricted Stock Units Activity Under Plan	The following summarizes restricted stock unit activity under the 2018 Plan: Outstanding Restricted Stock Units Restricted Stock Units Weighted- Weighted Average Remaining Vesting Life Aggregate Intrinsic Value (in years) (in thousands) Unvested December 31, 2021 4,261,108 $ 26.37 1.72 $ 63,576 Granted 3,316,499 9.74 1.89 Vested (991,967) 27.90 Forfeited (476,970) 22.24 Unvested September 30, 2022 6,108,670 $ 17.41 1.70 $ 65,974 Vested and expected to vest, September 30, 2022 6,108,670 $ 17.41 1.70 $ 65,974
Schedule of Stock-Based Compensation Expense	Total stock-based compensation related to stock options, restricted stock units, employee stock purchase plan and vesting of the founders’ common stock was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 11,016 $ 10,074 $ 35,068 $ 28,494 General and administrative 10,132 10,782 31,286 30,288 Total stock-based compensation $ 21,148 $ 20,856 $ 66,354 $ 58,782

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Potentially Dilutive Shares	The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the period presented due to their anti-dilutive effect: September 30, 2022 2021 Stock options to purchase common stock 18,122,447 10,109,169 Restricted stock units subject to vesting 6,108,670 3,393,604 Expected shares to be purchased under Employee Stock Purchase Plan 750,317 276,253 Founders' shares of common stock subject to future vesting — 3,028,848 Early exercised stock options subject to future vesting 162,532 1,057,793 Total 25,143,966 17,865,667

Description of Business (Detail

Description of Business (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents and marketable securities	$ 637,300
Accumulated deficit	$ 1,141,133	$ 903,348

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - Fair Value, Measurements, Recurring - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	$ 582,205,000	$ 752,034,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Financial liabilities	$ 0	$ 0

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	$ 582,205,000	$ 752,034,000
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	19,225,000	115,867,000
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	17,987,000	58,976,000
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	168,517,000	223,474,000
U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	332,334,000	303,016,000
U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	44,142,000	50,701,000
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	351,559,000	418,883,000
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	19,225,000	115,867,000
Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	332,334,000	303,016,000
Level 1 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	230,646,000	333,151,000
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	17,987,000	58,976,000
Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	168,517,000	223,474,000
Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 2 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	44,142,000	50,701,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	0	0
Level 3 | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets	$ 0	$ 0

Financial Instruments - Cash Eq

Financial Instruments - Cash Equivalents, Restricted Cash and Investments, Classified as Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 594,719	$ 754,157
Unrealized Gains	1	33
Unrealized Losses	(12,515)	(2,156)
Fair Value	582,205	752,034
Cash equivalents	19,225	115,867
Short-term investments	477,872	283,988
Long-term investments	85,108	352,179
Total cash equivalents and investments	582,205	752,034
Money market funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	19,225	115,867
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	19,225	115,867
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,995	58,981
Unrealized Gains	0	2
Unrealized Losses	(8)	(7)
Fair Value	17,987	58,976
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	172,278	224,092
Unrealized Gains	0	29
Unrealized Losses	(3,761)	(647)
Fair Value	168,517	223,474
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	339,145	304,142
Unrealized Gains	1	2
Unrealized Losses	(6,812)	(1,128)
Fair Value	332,334	303,016
U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	46,076	51,075
Unrealized Gains	0	0
Unrealized Losses	(1,934)	(374)
Fair Value	$ 44,142	$ 50,701

Financial Instruments - Additio

Financial Instruments - Additional Information (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Investments, All Other Investments [Abstract]
Maximum remaining contractual maturities of available-for-sale securities (in years)	2 years
Net unrealized loss position	$ 153,700,000	$ 0
Accrued interest receivable from available-fore-sale investments	$ 1,500,000	$ 1,900,000

Balance Sheet Components (Detai

Balance Sheet Components (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 149,030	$ 146,351
Less: accumulated depreciation	(34,588)	(23,361)
Total property and equipment, net	114,442	122,990
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	108,412	108,353
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	31,443	29,666
Computer equipment and purchased software
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	5,033	4,373
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	3,976	3,920
Construction in progress
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 166	$ 39

License and Collaboration Agr_2

License and Collaboration Agreements (Details) € in Millions			1 Months Ended		3 Months Ended		9 Months Ended
	Dec. 14, 2020 USD ($)	Oct. 06, 2020 USD ($)	Oct. 31, 2021 USD ($)	Feb. 28, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 EUR (€)	Jan. 05, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Nov. 01, 2019 USD ($)
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development					$ 63,641,000	$ 58,720,000	$ 180,968,000	$ 166,193,000
Equity method investment					14,046,000		14,046,000				$ 18,005,000
Payments for additional investment in interest							0	15,938,000
Collaboration revenue - related party					49,000	49,000	196,000	38,438,000
Payments for investments							200,318,000	474,801,000
University Of Texas MD Anderson Cancer Center
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration agreement, upfront payment												$ 3,000,000
Collaboration agreement term		5 years
Committed funding		$ 15,000,000
Allogene Overland, Allogene Overland BioPharm (HK) Limited
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Net cost recoveries					300,000	0	600,000	0
Collaboration revenue - related party					100,000	100,000	200,000	38,400,000
Reduction to research and development expense						0		0
Research and development | University Of Texas MD Anderson Cancer Center
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration arrangement, expense					200,000	400,000	1,100,000	800,000
Notch Therapeutics, Inc.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Equity method investment													$ 5,000,000
Ownership percentage													25%
Payments for additional investment in interest			$ 1,800,000	$ 15,900,000
Notch Therapeutics, Inc. | Voting Interest
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Ownership percentage			23%	20.70%
Allogene Overland
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Equity method investment					0		0				0
Ownership percentage	49%
Allogene Overland | Overland Pharmaceuticals Inc.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Ownership percentage	51%
Corporate Joint Venture | Allogene Overland | Overland Pharmaceuticals Inc.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Upfront and quarterly cash payments	$ 117,000,000
Joint venture capital support payments	40,000,000
Corporate Joint Venture | Allogene Overland | Allogene Overland, Allogene Overland BioPharm (HK) Limited
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments	40,000,000
Collaboration agreement, upfront payment	$ 40,000,000
Antion Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration agreement, upfront payment										$ 3,500,000
Collaboration arrangement, expense					600,000		4,500,000
Antion Collaboration Agreement | Current Accrued and Other Liabilities
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration arrangement, expense					500,000		500,000
Antion Collaboration Agreement | Preferred Stock
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments for investments							3,000,000
Payments for investments upon milestone achievement							$ 3,000,000
Antion Collaboration Agreement, Milestone Achievement One
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payable										35,300,000
Antion Collaboration Agreement, Milestone Achievement Two
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payable										$ 2,000,000
Pfizer
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty obligation period from date of first sale							12 years
Pfizer | Asset Contribution Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							$ 325,000,000
Milestone payments					0	0	0	0
Pfizer | Asset Contribution Agreement | Minimum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							30,000,000
Pfizer | Asset Contribution Agreement | Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							60,000,000
Aggregate potential regulatory and development milestones							840,000,000
Cellectis | Research Collaboration and License Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum payments required per product against selected target							185,000,000
Cellectis | Pre-Clinical Development Milestone | Research Collaboration and License Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development					0	5,000,000	0	10,000,000
Cellectis | Development and Sales | Maximum | Research Collaboration and License Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							$ 2,800,000,000
Servier | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of development costs payable by the Company							60%
Percentage of development cost payable by collaboration partner							40%
Net cost recoveries					3,800,000	5,100,000	$ 20,400,000	13,200,000
Due from related parties					4,300,000		4,300,000				$ 4,100,000
Servier | Regulatory Milestone | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone receivable					42,000,000		42,000,000
Servier | Regulatory Milestone | Maximum | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							137,500,000
Servier | Sales Milestone | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone receivable					69,100,000		69,100,000		€ 70.5
Servier | Sales Milestone | Maximum | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							78,000,000
Notch Therapeutics, Inc. | Research and development
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration arrangement, expense					1,000,000	$ 800,000	2,800,000	$ 3,900,000
Notch Therapeutics, Inc. | Research Collaboration and License Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payable					$ 7,250,000		7,250,000
Notch Therapeutics, Inc. | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration agreement, upfront payment													$ 10,000,000
Notch Therapeutics, Inc. | Pre-Clinical Development Milestone | Maximum | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							4,000,000
Notch Therapeutics, Inc. | Clinical, Regulatory, and Commercial Milestone | Maximum | License and Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate potential milestone payments							$ 283,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended	9 Months Ended
	Feb. 28, 2019 ft² renewal	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($) ft²	Jul. 31, 2020 USD ($)	Oct. 31, 2018 USD ($) ft²	Aug. 31, 2018 ft²
Operating Leased Assets [Line Items]
Area of office and laboratory (in square feet) | ft²					14,943	68,000
Operating lease term					124 months	127 months
Operating lease, option to extend term (in years)					7 years	7 years
Tenant improvements		$ 5
Additional area of office and laboratory (in square feet) | ft²			47,566
Allowance for tenant improvements					$ 0.8
Letter of credit		6	$ 6
Cash paid for amounts included in measurement of lease liabilities		$ 2.6
Weighted average discount rate (as a percent)		6.19%
Weighted average remaining lease term (in years)		10 years 2 months 15 days
Agreement term				20 years
Termination payment				$ 4.3
Non-cancellable purchase commitments		$ 0.4
Lease One, Amended
Operating Leased Assets [Line Items]
Operating lease term			120 months
Operating lease, option to extend term (in years)			8 years
Lease Two
Operating Leased Assets [Line Items]
Operating lease, option to extend term (in years)			8 years
Letter of Credit
Operating Leased Assets [Line Items]
Letter of credit		4.3
Newark
Operating Leased Assets [Line Items]
Operating lease term	188 months
Operating lease, option to extend term (in years)	10 years
Area of operating lease (in square feet) | ft²	118,000
Number of options to extend lease | renewal	2
Tenant improvement allowance utilized to date		$ 3

Commitments and Contingencies_2

Commitments and Contingencies - Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued and other current liabilities	Accrued and other current liabilities
Current portion included in accrued and other current liabilities	$ 5,831	$ 3,200
Long-term portion of lease liabilities	96,706	69,929
Total operating lease liabilities	$ 102,537	$ 73,129

Commitments and Contingencies_3

Commitments and Contingencies - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 3,177	$ 1,853	$ 8,476	$ 5,568
Variable lease cost	616	448	1,468	979
Total lease costs	$ 3,793	$ 2,301	$ 9,944	$ 6,547

Commitments and Contingencies_4

Commitments and Contingencies - Undiscounted Future Lease Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
2022 (remaining 6 months)	$ 2,943
2023	12,065
2024	12,464
2025	12,636
2026	12,819
2027 and thereafter	90,492
Total undiscounted lease payments	143,419
Less: Present value adjustment	(40,882)
Total operating lease liabilities	$ 102,537	$ 73,129

Equity Method Investments (Deta

Equity Method Investments (Details) - USD ($)		1 Months Ended		9 Months Ended
	Nov. 01, 2019	Oct. 31, 2021	Feb. 28, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Dec. 14, 2020
Schedule of Equity Method Investments [Line Items]
Payments for additional investment in interest				$ 0	$ 15,938,000
Equity method investment				14,046,000		$ 18,005,000
Notch Therapeutics, Inc.
Schedule of Equity Method Investments [Line Items]
Payments to acquire interest in Notch	$ 5,100,000
Transaction cost	$ 100,000
Ownership percentage	25%
Payments for additional investment in interest		$ 1,800,000	$ 15,900,000
Equity method investment	$ 5,000,000
Notch Therapeutics, Inc. | Voting Interest
Schedule of Equity Method Investments [Line Items]
Ownership percentage		23%	20.70%
Allogene Overland
Schedule of Equity Method Investments [Line Items]
Ownership percentage							49%
Equity method investment				0		0
Carrying value				$ 0		$ 0	$ 0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Millions		9 Months Ended
	Jul. 19, 2022 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 shares	Jun. 21, 2022 employee shares	Dec. 31, 2021 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares as percentage of common shares outstanding		5%
Number of shares reserved for future issuance (in shares) | shares		12,035,820
Plan modification, incremental cost	$ 5.2
Expected dividend rate		0%
Expected exercise barrier (in dollars per share) | $ / shares		$ 2.57
Issuance of common stock upon exercise of stock options and vesting of RSUs (in shares) | shares		0	293,594
Accrued and other liabilities, related to shares held by employees and directors that were subject to repurchase		$ 1.9			$ 2.9
Other long term liabilities, related to shares held by employees and directors that were subject to repurchase		$ 1.1			$ 2.5
Stock options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years	4 years
Exchange offer, number of employees | employee				199
Exchange offer, number of options accepted for cancellation (in shares) | shares				3,666,600
Exchange offer, percentage of total shares outstanding				0.935
Number of options, options granted (in shares) | shares	3,666,600
Weighted average exercise price (in dollars per share) | $ / shares	$ 13.31
Expiration period	7 years
Grants in period, weighted average grant date fair value (in dollars per share) | $ / shares		$ 9.99
Unrecognized stock based compensation expense		$ 96.7
Unrecognized stock based compensation expense, weighted average recognition period (in years)		2 years 324 days
Expected volatility		73.74%
Expected risk-free rate		3.06%
Expected dividend rate		0%
Expected exercise barrier (in dollars per share) | $ / shares		$ 2.57
Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		4 years
Unrecognized stock based compensation expense		$ 85
Unrecognized stock based compensation expense, weighted average recognition period (in years)		2 years 240 days
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option grant period		10 years
Option exercise price as percentage of fair value of common stock on grate date		100%

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Number of Options
Number of options, options exercised (in shares)	0	(293,594)
2018 Plan
Number of Options
Number of options, beginning balance (in shares)	10,239,167
Number of options, options granted (in shares)	8,627,428
Number of options, options exercised (in shares)	(174,451)
Number of options, options forfeited (in shares)	(569,697)
Number of options, option exchange, options cancelled (in shares)	(3,666,600)
Number of options, option exchange, options granted (in shares)	3,666,600
Number of options, ending balance (in shares)	18,122,447		10,239,167
Number of options, exercisable (in shares)	13,657,219
Number of options, vested and expected to vest (in shares)	18,122,447
Weighted- Average Exercise Price
Weighted-average exercise price, beginning balance (in dollars per share)	$ 21.10
Weighted-average exercise price, options granted (in dollars per share)	9.64
Weighted-average exercise price, options exercised (in dollars per share)	2.33
Weighted-average exercise price, options forfeited (in dollars per share)	24.41
Weighted-average exercise price, option exchange options cancelled (in dollars per share)	26.82
Weighted-average exercise price, option exchange options granted (in dollars per share)	13.31
Weighted-average exercise price, ending balance (in dollars per share)	12.99		$ 21.10
Weighted-average exercise price, exercisable (in dollars per share)	13.04
Weighted-average exercise price, vested and expected to vest (in dollars per share)	$ 12.99
Weighted-average remaining contract term, outstanding (in years)	8 years 18 days		7 years 8 months 4 days
Weighted-average remaining contract term, exercisable (in years)	8 years 3 months 14 days
Weighted-average remaining contract term, vested and expected to vest (in years)	8 years 18 days
Aggregate intrinsic value, balance	$ 25,996		$ 26,223
Aggregate intrinsic value, exercisable	24,715
Aggregate intrinsic value, vested and expected to vest	$ 25,996

Stock-Based Compensation - Valu

Stock-Based Compensation - Valuation Assumptions (Details)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend rate	0%
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	70.82%	69.73%
Expected volatility, maximum	73.39%	70.80%
Expected risk-free interest rate, minimum	1.61%	0.60%
Expected risk-free interest rate, maximum	3.49%	1.16%
Expected dividend rate	0%	0%
2018 Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years	5 years 3 months	5 years 3 months 7 days
2018 Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years	6 years 29 days	6 years 29 days

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units Activity (Details) - Restricted Stock Unit - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Restricted Stock Units
Restricted stock units, unvested, beginning balance (in shares)	4,261,108
Restricted stock units, granted (in shares)	3,316,499
Restricted stock units, vested (in shares)	(991,967)
Restricted stock units, forfeited (in shares)	(476,970)
Restricted stock units, unvested, ending balance (in shares)	6,108,670	4,261,108
Restricted stock units, vested and expected to vest (in shares)	6,108,670
Weighted- Average Grant Date Fair Value per Share
Weighted-average fair value at date of grant per share, beginning balance (in dollars per share)	$ 26.37
Weighted-average fair value at date of grant per share, granted (in dollars per share)	9.74
Weighted-average fair value at date of grant per share, vested (in dollars per share)	27.90
Weighted-average fair value at date of grant per share, forfeited (in dollars per share)	22.24
Weighted-average fair value at date of grant per share, ending balance (in dollars per share)	17.41	$ 26.37
Weighted-average fair value at date of grant per share, vested and expected to vest (in dollars per share)	$ 17.41
Weighted average remaining vesting life, unvested (in years)	1 year 8 months 12 days	1 year 8 months 19 days
Weighted average remaining vesting life, granted (in years)	1 year 10 months 20 days
Weighted average remaining vesting life, vested and expected to vest (in years)	1 year 8 months 12 days
Aggregate intrinsic value, unvested	$ 65,974	$ 63,576
Aggregate intrinsic value, vested and expected to vest	$ 65,974

Stock-Based Compensation - Expe

Stock-Based Compensation - Expense (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, Compensation Cost [Line Items]
Total stock-based compensation	$ 21,148	$ 20,856	$ 66,354	$ 58,782
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	11,016	10,074	35,068	28,494
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 10,132	$ 10,782	$ 31,286	$ 30,288

Related Party Transactions (Det

Related Party Transactions (Details)	1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2022 ft²	Dec. 31, 2018 ft²	Aug. 31, 2018	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Related Party Transaction [Line Items]
Collaboration revenue - related party				$ 49,000	$ 49,000	$ 196,000	$ 38,438,000
Operating lease right-of-use asset				85,245,000		85,245,000		$ 58,030,000
Operating lease liability				102,537,000		102,537,000		73,129,000
Allogene Overland, Allogene Overland BioPharm (HK) Limited
Related Party Transaction [Line Items]
Collaboration revenue - related party				100,000	100,000	200,000	38,400,000
Net cost recoveries				300,000	0	600,000	0
Bellco | Sublease Agreement
Related Party Transaction [Line Items]
Area of office space (in square feet) | ft²	737	1,293
Sublease, term of contract (in years)		3 years
Operating lease right-of-use asset				200,000		200,000		300,000
Operating lease liability				200,000		200,000		300,000
Bellco | Consulting Agreements
Related Party Transaction [Line Items]
Related party costs				200,000	200,000	600,000	600,000
Bellco | Consulting Agreements | Payments Commencing January 2021
Related Party Transaction [Line Items]
Related party transaction monthly payment in arrears								$ 38,583
Bellco | Consulting Agreements | Payments Commencing January 2022
Related Party Transaction [Line Items]
Related party transaction monthly payment in arrears						40,217
Bellco | Consulting Agreements | Maximum
Related Party Transaction [Line Items]
Related party transaction compensation percentage			60%
Two River | Consulting Agreements
Related Party Transaction [Line Items]
Related party costs				$ 100,000	$ 200,000	$ 600,000	$ 400,000

Net Loss Per Share (Details)

Net Loss 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 shares excluded from calculation of diluted net loss per share (in shares)	25,143,966	17,865,667
Stock options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted net loss per share (in shares)	18,122,447	10,109,169
Restricted stock units subject to vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted net loss per share (in shares)	6,108,670	3,393,604
Expected shares to be purchased under Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted net loss per share (in shares)	750,317	276,253
Founders' shares of common stock subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted net loss per share (in shares)	0	3,028,848
Early exercised stock options subject to future vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted net loss per share (in shares)	162,532	1,057,793

Subsequent Events (Details)

Subsequent Events (Details) $ in Millions	Oct. 06, 2022 USD ($)
Subsequent Event
Subsequent Event [Line Items]
Collaborative arrangement, rights and obligations, milestone payment	$ 8