BPX-501 Proven to Reduce Cancer Recurrence Rates in AML Patients

Interim clinical data from the ongoing BP-004 trial suggest that BPX-501 reduces cancer recurrence rates in pediatric patients with acute myeloid leukemia (AML) and primary immunodeficiencies (PIDs).

According to the data, BPX-501 T cells may contribute to a durable anti-leukemic effect in patients with AML. 38 pediatric AML patients were enrolled in the study, and underwent a haploidentical hematopoietic stem cell transplant (haplo-HSCT) followed by treatment with BPX-501 in either their first (n=13) or second (n=25) complete response. Rates of relapse-free survival and overall survival (OS) were 91.5% and 97.3%, respectively.

Comparatively, historical data shows one-year rates reported in AML patients undergoing alternate donor HSCT is approximately 60% and 80%.

AML first presents in the bone marrow and rapidly spreads to the blood. It is characterized by the swift expansion of white blood cells, and the enflamed cells impede the creation and development of classic blood cells. BPX-501 is being developed as an adjunct T cell therapy incorporating CaspaCIDe technology, and administered after haplo-HSCT for the treatment of hematologic cancers and inherited blood diseases.

“The recurrence of cancer is one of the most serious risks to AML patients receiving a stem cell transplant. These impressive results in children with AML suggest that BPX-501 may be effectively reducing or eradicating residual cancer cells following a haplo-transplant procedure,” commented Neena Kapoor, M.D., Director of the Blood and Marrow Transplantation Program at Children’s Hospital of Los Angeles and an investigator in the BP-004 trial in a press release.

The drug, in development by Bellicum Pharmaceuticals, Inc., is designed to provide a safety net to eliminate alloreactive BPX-501 T cells in the event that irrepressible GvHD or other T-cell mediated complications transpire. This permits physicians to safely perform stem cell transplants by administering BPX-501 engineered T cells to speed immune reconstitution, provide control over viral infections, and enhance Graft-versus-leukemic effect without unacceptable GvHD risk.

“Delayed immune reconstitution can lead to severe infectious complications, a major cause of morbidity and mortality in PID patients who undergo a T-depleted haplo-HSCT,” continued Dr Kapoor. “BPX-501 donor T cells administered after a transplant support immune recovery in these patients, and the CaspaCIDe safety switch engineered into BPX-501 may provide a critical safety net to address the risk of uncontrolled GvHD from donor T cells.”

The ongoing BPX-501 clinical study is being conducted at several transplant centers throughout the U.S. and Europe. Based on these clinical data, Bellicum will continue to work with the investigators and the U.S. Food and Drug Administration (FDA) to develop a protocol for a potential U.S. registration study in pediatric patients.

Pending regulatory clearances, Bellicum intends to initiate the study by the end of 2018.

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