Allogene’s CAR T trials halted due to safety concerns

Published: 8 October 2021

Following the report of a chromosomal abnormality in ALLO-501A CAR T cells in a patient treated in the ALPHA2 study, The FDA has placed a hold on all of the company’s AlloCAR T clinical trials.

After infusion of ALLO-501A, a patient with stage IV transformed follicular lymphoma and c-myc rearrangement, who had been through several prior lines of treatment, developed grade 1 cytokine release syndrome and grade 2 immune effector cell-associated neurotoxicity syndrome. The patient went on to develop progressive pancytopenia, and a bone marrow biopsy showed aplastic anemia and the presence of ALLO-501A CAR T cells with the chromosomal abnormality.

The clinical significance of the finding is currently unclear, but in response, the FDA has halted all of Allogene’s AlloCAR T clinical trials. Of most concern is the possibility that the chromosomal abnormalities discovered could cause cancer.

In a press release, Allogene announced it expects to provide additional updates in the coming weeks following consultation with the FDA. At the time of writing, Allogene has dosed over 100 patients with its gene-edited AlloCAR T products.

“Patient safety is our highest priority, and we are committed to working closely with the FDA to evaluate any potential clinical implications of this finding, and determine next steps for advancing ALLO-501A and our clinical programs,” said Rafael Amado, Executive Vice President of Research and Development and Chief Medical Officer, in a press release. “As a leading developer of allogeneic cell therapies, we recognize our added responsibility to fully assess all aspects of our therapies to advance the field. We are grateful for the partnership with the patient community, clinical investigators, our Scientific Advisory Board, and the FDA as we work diligently toward understanding the clinical significance of this finding and to support the development of allogeneic CAR T therapy for cancer.”