Exhibit 99.1

CARGO Therapeutics Reports Business Updates and Third Quarter 2023 Results

SAN MATEO, Calif., December 13, 2023 – CARGO Therapeutics, Inc. (Nasdaq: CRGX), a clinical-stage biotechnology company positioned to advance next generation, potentially curative cell therapies for cancer patients, today reported business updates and its financial results for the third quarter ended September 30, 2023.

“This year has been transformational for our company. We experienced growth across our business, including expanding our leadership team, commencing a Phase 2 clinical trial of CRG-022, and becoming a publicly traded company,” said Gina Chapman, President and Chief Executive Officer of CARGO. “While CAR T-cell therapies have changed the treatment landscape for patients with LBCL, patients whose disease relapses or is refractory to CD19 CAR T-cell therapy face a median survival of less than 6 months. We continue to believe that CRG-022 has the potential to alter the treatment paradigm for patients whose disease has relapsed or is refractory to CD19 CAR T. We are very pleased to have started our Phase 2 clinical trial which represents a key milestone as we work toward our goal of developing and delivering potentially curative therapies to more patients.”

Third Quarter and Subsequent Highlights

Phase 2 Clinical Trial of CRG-022 CAR T-Cell Therapy in Patients with Relapsed or Refractory (R/R) Large B-cell Lymphoma (LBCL): CARGO announced that it has dosed the first seven patients in its potentially pivotal Phase 2 multicenter clinical trial (NCT05972720) after successfully manufacturing CRG-022, the Company’s autologous CD22 chimeric antigen receptor (CAR) T-cell product candidate. CD22 is a common B-cell antigen widely expressed in the vast majority of B-cell malignancies, including LBCL. The clinical trial is an open-label, multicenter Phase 2 clinical trial evaluating the efficacy and safety of CRG-022 in patients with R/R LBCL whose disease has progressed after CD19-directed CAR T-cell therapy, an area of high unmet need.

Phase 1 Clinical Trial Updates: During the American Society of Hematology (ASH) 2023 Annual Meeting in early December, Stanford shared updated data from its ongoing Phase 1 clinical trial in patients with LBCL that was R/R to CD19 CAR T-cell therapy (NCT04088890). The update reflects a recent data cut-off as of November 4, 2023. The previous data cut-off was May 3, 2023. The updated data that was shared included:

Other Corporate Highlights

Third Quarter 2023 Financial Results

Upcoming Events

CARGO will participate in the 42nd Annual J.P. Morgan Healthcare Conference, taking place January 8-11, 2024, in San Francisco, California. Gina Chapman, President and Chief Executive Officer, is scheduled to present on Monday, January 8, at 9:45 AM PT.

About Large B-Cell Lymphoma (LBCL)

Lymphoma that affects B lymphocytes are called B-cell lymphomas. B-cells make antibodies to fight infections and are an important part of the human immune system. B-cell lymphomas account for approximately 85% of non-Hodgkin lymphomas (NHL) in the United States. LBCL is an aggressive (fast-growing) lymphoma that occurs most commonly in people over the age of 60, though it can occur in childhood.

About CRG-022

CRG-022 is CARGO’s investigational cell therapy that is composed of autologous T-cells transduced with a lentiviral vector (m971-BBZ) expressing a CD22-targeting CAR. CD22 is a transmembrane protein expressed on normal B-cells and B-cell malignancies. Results of an ongoing Phase 1 clinical trial in adults demonstrate the safety and antitumor activity of CRG-022 in patients with LBCL whose disease is relapsed or refractory (R/R) to CD19 CAR T-cell therapy. Based on Phase 1 results, Stanford University was granted Breakthrough Therapy Designation from the FDA for the treatment of adult LBCL patients whose disease is R/R after CD19-directed CAR T-cell therapy. CRG-022 has a unique design which is associated with efficacy in the clinic that has not been seen with other CD22 CAR Ts. CARGO believes that CRG-022 has the potential to safely and effectively treat LBCL, including patients for whom prior CD19 CAR T-cell therapies have failed.

About CARGO Therapeutics

CARGO Therapeutics, Inc. is a clinical-stage biotechnology company positioned to advance next generation, potentially curative cell therapies for cancer patients. CARGO’s programs, platform technologies, and manufacturing strategy are designed to directly address the limitations of approved cell therapies, including limited durability of effect, safety concerns and unreliable supply. CARGO is currently evaluating its lead program, CRG-022, an autologous CD22 chimeric antigen receptor (CAR) T-cell therapy candidate, in a potentially pivotal Phase 2 clinical trial in patients with large B-cell lymphoma (LBCL) whose disease relapsed or was refractory (R/R) to CD19 CAR T-cell therapy. CARGO also plans to evaluate CRG-022 in patients at earlier stages of disease, including LBCL and other hematologic malignancies. Beyond its lead program, CARGO is leveraging its proprietary cell engineering platform technologies to develop a pipeline of programs that incorporate multiple transgene therapeutic “cargo” designed to enhance CAR T-cell persistence and trafficking to tumor lesions, as well as to help safeguard against tumor resistance and T-cell exhaustion. CARGO’s founders are pioneers and world-class experts in CAR T-cell therapy, and its team has significant experience and success developing, manufacturing, launching and commercializing oncology and cell therapy products. For more information, please visit the CARGO Therapeutics website at https://cargo-tx.com/.

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Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In some cases, you can identify forward-looking statements by terminology such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “design,” “due,” “estimate,” “expect,” “goal,” “intend,” “may,” “objective,” “plan,” “positioned,” “potential,” “predict,” “seek,” “should,” “target,” “will,” “would” and other similar expressions that are predictions of or indicate future events and future trends, or the negative of these terms or other comparable terminology. All statements other than statements of historical facts contained in this press release are forward-looking statements. These forward-looking statements include, but are not limited to, statements about: advancement of CARGO’s clinical programs; the potential benefits from treatment with CD19 CAR T-cell therapies; timing of data reports including the release of interim data from the Company’s ongoing Phase 2 clinical trial of CRG-022; and the implementation of CARGO’s strategic plans for its business and product candidates, including additional indications which the company may pursue; and whether the Company’s cash and cash equivalents will be able to fund operations through 2025. Forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including, but not limited to, risks and uncertainties related to: the company’s ability to obtain necessary capital to fund its clinical programs; the early stages of clinical development of the company’s product candidates; the company’s ability to obtain regulatory approval of and successfully commercialize its product candidates; any undesirable side effects or other properties of the company’s product candidates; the company’s reliance on third-party suppliers and manufacturers, including CROs; the outcomes of any future collaboration agreements; and the company’s ability to adequately maintain intellectual property rights for its product candidates. These and other risks are described in greater detail under the section titled Risk Factors” contained in the company’s prospectus filed with the Securities and Exchange Commission (SEC) on November 13, 2023, pursuant to Rule 424(b) under the Securities Act and the company’s other filings with the SEC. Any forward-looking statements that the company makes in this press release are made pursuant to the Private Securities Litigation Reform Act of 1995, as amended, and speak only as of the date of this press release. Except as required by law, the company undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.

CARGO Therapeutics, Inc.

Condensed Consolidated Statement of Operations

(Unaudited)

CARGO Therapeutics, Inc.

Condensed Consolidated Balance Sheets

(Unaudited)

Media Contact:

Maura Gavaghan

maura@redhousecomms.com

Investor Contact:

Laurence Watts

laurence@gilmartinir.com