Nature of the Business	12 Months Ended
Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of The Business	1. Nature of the Business Organization Arcellx, Inc. (Arcellx or the Company) was incorporated in Delaware in December 2014 and is headquartered in Redwood City, California. The Company is a clinical-stage biopharmaceutical company reimagining cell therapy through the development of innovative therapies for patients with cancer and other incurable diseases. Public Offerings On February 8, 2022, the Company closed its initial public offering of 9,487,500 shares of its common stock, including the exercise in full by the underwriters of their option to purchase 1,237,500 additional shares of its common stock, at a public offering price of $15.00 per share. The Company received net proceeds of $127.3 million, after deducting underwriting discounts and commissions of and other offering expenses paid by the Company of approximately $15.0 million. On June 21, 2022, the Company closed a follow-on public offering of 8,050,000 shares of its common stock, including the exercise in full by the underwriters of their option to purchase 1,050,000 additional shares of its common stock, at a public offering price of $16.00 per share. The Company received net proceeds of $120.7 million after deducting underwriting discounts and commissions and other offering expenses paid by the Company of approximately $8.1 million. Liquidity The Company has not commercialized any of its drug candidates and planned commercial operations have not commenced. The Company expects to incur additional operating losses and negative operating cash flows for the foreseeable future as it continues development of drug candidates, including preclinical and clinical testing and regulatory approval prior to commercialization. The Company has not generated any revenue to date from product sales and does not expect to generate any revenues from product sales in the foreseeable future. The Company plans to seek additional funding through public or private equity offerings or debt financings. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into other arrangements on favorable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be required to delay, reduce or eliminate research and development programs, product portfolio expansion or future commercialization efforts, which could adversely affect its business prospects. The Company has incurred significant operating losses since inception and has an accumulated deficit of $389.5 million as of December 31, 2023. The Company has relied on its ability to fund its operations through private and public equity financings, and its recent collaboration and license agreement with Kite Pharma, Inc. (Kite), a Gilead Sciences, Inc. (Gilead) company. In January 2023, the Company received in the aggregate $325.0 million in cash which consisted of $100.0 million related to a private placement from the sale of the Company’s common stock to Gilead and a $225.0 million non-refundable, upfront payment related to the closing of its Collaboration and License Agreement (Kite Collaboration Agreement) with Kite. On December 28, 2023, the Company received in the aggregate $285.0 million in cash which consisted of $200.0 million related to a private placement from the sale of the Company’s common stock to Gilead and a $85.0 million non-refundable, upfront payment related to the closing of its amendment to the Kite Collaboration Agreement with Kite. See Note 8 Collaboration Agreement. As of December 31, 2023, the Company had $729.2 million of cash, cash equivalents and marketable securities, which management believes will be sufficient to meet the Company’s anticipated operating and capital expenditure requirements for at least twelve months following the date of issuance of these financial statements.

Nature of the Business

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Nature of the Business

Organization

Arcellx, Inc. (Arcellx or the Company) was incorporated in Delaware in December 2014 and is headquartered in Redwood City, California. The Company is a clinical-stage biopharmaceutical company reimagining cell therapy through the development of innovative therapies for patients with cancer and other incurable diseases.

Public Offerings

On February 8, 2022, the Company closed its initial public offering of 9,487,500 shares of its common stock, including the exercise in full by the underwriters of their option to purchase 1,237,500 additional shares of its common stock, at a public offering price of $15.00 per share. The Company received net proceeds of $127.3 million, after deducting underwriting discounts and commissions of and other offering expenses paid by the Company of approximately $15.0 million.

On June 21, 2022, the Company closed a follow-on public offering of 8,050,000 shares of its common stock, including the exercise in full by the underwriters of their option to purchase 1,050,000 additional shares of its common stock, at a public offering price of $16.00 per share. The Company received net proceeds of $120.7 million after deducting underwriting discounts and commissions and other offering expenses paid by the Company of approximately $8.1 million.

Liquidity

The Company has not commercialized any of its drug candidates and planned commercial operations have not commenced. The Company expects to incur additional operating losses and negative operating cash flows for the foreseeable future as it continues development of drug candidates, including preclinical and clinical testing and regulatory approval prior to commercialization. The Company has not generated any revenue to date from product sales and does not expect to generate any revenues from product sales in the foreseeable future. The Company plans to seek additional funding through public or private equity offerings or debt financings. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into other arrangements on favorable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be required to delay, reduce or eliminate research and development programs, product portfolio expansion or future commercialization efforts, which could adversely affect its business prospects.

The Company has incurred significant operating losses since inception and has an accumulated deficit of $389.5 million as of December 31, 2023. The Company has relied on its ability to fund its operations through private and public equity financings, and its recent collaboration and license agreement with Kite Pharma, Inc. (Kite), a Gilead Sciences, Inc. (Gilead) company. In January 2023, the Company received in the aggregate $325.0 million in cash which consisted of $100.0 million related to a private placement from the sale of the Company’s common stock to Gilead and a $225.0 million non-refundable, upfront payment related to the closing of its Collaboration and License Agreement (Kite Collaboration Agreement) with Kite. On December 28, 2023, the Company received in the aggregate $285.0 million in cash which consisted of $200.0 million related to a private placement from the sale of the Company’s common stock to Gilead and a $85.0 million non-refundable, upfront payment related to the closing of its amendment to the Kite Collaboration Agreement with Kite. See Note 8 Collaboration Agreement.

As of December 31, 2023, the Company had $729.2 million of cash, cash equivalents and marketable securities, which management believes will be sufficient to meet the Company’s anticipated operating and capital expenditure requirements for at least twelve months following the date of issuance of these financial statements.