On August 1, 2025 Allogene Therapeutics, Inc. (Nasdaq: ALLO), a clinical-stage biotechnology company pioneering the development of allogeneic CAR T (AlloCAR T) products for cancer and autoimmune disease, reported that it has selected standard fludarabine and cyclophosphamide (FC) as the lymphodepletion regimen to be used in its ALPHA3 study evaluating cemacabtagene ansegedleucel (cema-cel) in first-line consolidation for large B-cell lymphoma (LBCL) (Press release, Allogene, AUG 1, 2025, View Source [SID1234654703]). This lymphodepletion regimen selection was made in conjunction with the ALPHA3 Data and Safety Monitoring Board (DSMB) and Steering Committee and following consultation with the U.S. Food and Drug Administration (FDA).

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The arm testing FC plus ALLO-647, an anti-CD52 mAb (FCA), is now closed to further enrollment. This decision, made ahead of the scheduled futility analysis, was prompted by a Grade 5 adverse event in the FC plus ALLO-647 arm that has been attributed to the use of ALLO-647. The event occurred on Day 54 post-infusion from hepatic failure, believed to have resulted from disseminated adenovirus infection in the setting of immune suppression. This event was deemed unrelated to cema-cel. Severe viral infections have been rare across Allogene’s clinical trials. However, when present, they have been attributed to immunosuppression due in part to ALLO-647. There have been no cases of adenoviral infection or hepatic failure in any participant treated with FC lymphodepletion across Allogene’s trials.

"The loss of a patient is always deeply saddening, and we extend our heartfelt condolences to the patient’s family," said David Chang, M.D., Ph.D., President, Chief Executive Officer, and Co-Founder of Allogene. "This event, which prompted an early review of the trial data, compelled us to make a decisive choice – one that may ultimately help bring this potentially life-saving therapy to patients more quickly. The ability to administer cema-cel following standard FC lymphodepletion in an outpatient setting will simplify study treatment and has the potential to accelerate trial enrollment and streamline regulatory review, ultimately transforming care for patients."

The adoption of standard FC in the ALPHA3 trial marks a key shift in Allogene’s clinical strategy. As a result, no trials open to enrollment or pipeline programs include ALLO-647. Instead, the Company is advancing its next-generation AlloCAR T product candidates using the proprietary Dagger Platform Technology, which is designed to minimize or potentially eliminate the need for standard lymphodepletion. This approach is showcased in the ALLO-316 TRAVERSE trial for advanced renal cell carcinoma and the ALLO-329 RESOLUTION trial for autoimmune diseases, both of which leverage the Dagger Technology to reduce reliance on traditional lymphodepletion strategies.

The amended ALPHA3 trial now proceeds as a randomized study with two arms, comparing cema-cel after standard FC lymphodepletion to observation, the current standard of care. Statistical design of the trial and the prespecified study conduct remain the same. The next milestone will be the futility analysis comparing MRD conversion and is expected to occur 1H 2026. To date, over 50 clinical sites are activated across the United States and Canada, including community cancer centers and major academic institutions.

Conference Call and Webcast Details
Allogene will host a live conference call and webcast today at 8:00 a.m. PT / 11:00 a.m. ET to discuss this recent update. If you would like the option to ask a question on the conference call, please use this link to register. Upon registering for the conference call, you will receive a personal PIN to access the call, which will identify you as the participant and allow you the option to ask a question. The listen-only webcast will be made available on the Company’s website at www.allogene.com under the Investors tab in the News and Events section. Following the live audio webcast, a replay will be available on the Company’s website for approximately 30 days.

About Cemacabtagene Ansegedleucel (cema-cel)
Cemacabtagene ansegedleucel, or cema-cel, is a next generation anti-CD19 AlloCAR T investigational product for the treatment of large B cell lymphoma (LBCL). The ALPHA3 pivotal Phase 2 trial in first line (1L) consolidation for the treatment of LBCL launched in June 2024. Allogene has oncology rights to cema-cel in the US, EU and UK with options for rights in China and Japan.

About the ALPHA3 Trial
Over 60,000 patients are expected to be treated for LBCL annually in the US, the EU and the UK. While first line (1L) R-CHOP or other chemoimmunotherapy is effective for most patients, approximately 30% who initially respond will relapse and require subsequent treatment. The current standard of care after 1L treatment has been simply to "watch and wait" to see if the disease relapses. The pivotal Phase 2 ALPHA3 study takes advantage of cema-cel as a one-time, "off-the-shelf" treatment that can be administered immediately upon discovery of MRD following six cycles of R-CHOP or other chemoimmunotherapy, positioning it to become the standard "7th cycle" of frontline treatment available to all eligible patients with MRD.