Hemogenyx shares details of CAR-T clinical hold

July 11, 2023

London-based Hemogenyx Pharmaceuticals has shared the details of an FDA clinical hold letter received last month for the company's IND for its CAR-T candidate for the treatment of acute myeloid leukemia.

The review letter contains a detailed description of the agency's rationale for the decision to put the IND for the company's lead candidate, HEMO-CAR-T, on hold. The hold relates to a splicing that occurs during the manufacturing process of the lentivirus that is used to produce CAR-T cells. According to Hemogenyx, the company has "identified the source of the splicing deficiency and has already developed a method to eliminate it," and the lentivirus is currently being remanufactured. 

Hemogenyx said the letter also contained several suggestions on how to improve the safety of HEMO-CAR-T — but that those suggestions are not contributing to the hold and can be dealt with readily.  

Hemogenyx has submitted the IND for the phase 1 clinical trial of HEMO-CAR-T back in May, and revealed the hold, lacking details, a month later. The candidate targets AML, the most common type of acute leukemia in adults. Current standard of care is chemotherapy, but AML has poor survival rates. and is currently treated using chemotherapy. Hemogenyx claims that HEMO-CAR-T is  potentially a "more benign and effective form of therapy."

To date, the FDA has only approved six CAR-T therapies. It is not unusual for candidates to run into clinical holds as the agency proceeds with caution. In recent news, the FDA placed a hold on Arcellx's IND for its multiple myeloma CAR-T, following a patient death in a mid-stage trial. Massachusetts-based 2seventy bio paused an early stage trial of its CAR T-cell therapy in acute myeloid leukemia, following the death of a young patient.