Three cases of encephalopathy deemed as possibly related to BPX 501 halts trial.

Bellicum Pharmaceuticals announced that the Company has received notice from the FDA that U.S. studies of BPX 501 in Graft vs. Host Disease have been placed on a clinical hold following three cases of encephalopathy deemed as possibly related to BPX 501. Bellicum is awaiting formal communications from the FDA to determine the requirements for resuming studies, and will be working closely with the FDA to address their questions. The FDA clinical hold does not affect the ongoing BP-004 registration trial in Europe.

Encephalopathy has been reported in the allogeneic stem cell transplant literature. Risk factors for encephalitis/encephalopathy after allogeneic stem cell transplants include prolonged immunodeficiency, selected medications, infections, and inflammatory processes such as graft versus host disease. Bellicum has treated more than 240 patients with BPX 501 cells on three allogeneic haploidentical stem cell transplantation protocols. These three cases are complex, with a number of potential confounding factors—including, in certain of the cases, prior failed transplants, prior history of immunodeficiency, concurrent infection, and administration of rimiducid in combination with other medications. Bellicum is working with FDA to evaluate the risk of encephalopathy in patients receiving BPX 501.