Allogene Therapeutics selects lymphodepletion regimen for ALPHA3 study

Allogene Therapeutics (ALLO) announced that it has selected standard fludarabine and cyclophosphamide as the lymphodepletion regimen to be used in its ALPHA3 study evaluating cemacabtagene ansegedleucel in first-line consolidation for large B-cell lymphoma, LBCL. 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. 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.