Bellicum Pharmaceuticals, Inc., a clinical stage biopharmaceutical company focused on discovering and developing novel cellular immunotherapies for cancers and orphan inherited blood disorders, has announced the presentation of interim data from the lead site in the ongoing BP-004 Phase 1/2 clinical trial during the 57th Annual Meeting of the American Society of Hematology (ASH) in Orlando, Florida. Pediatric patients in the study with a variety of genetic diseases achieved disease-free outcomes following a haploidentical, T cell-depleted hematopoietic stem cell transplant (HSCT) followed by an add-back of BPX-501 donor T cells. The study is designed to evaluate whether this regimen is safe and improves immune reconstitution, infection control and overall outcomes.

Initial outcomes were reported from the 39 pediatric patients who have received the BPX-501 product (of a total of 49 enrolled) at the European trial site as of November 30. Twenty of these children had non-malignant genetic diseases including Fanconi anemia (5), beta thalassemia (4), severe combined immunodeficiency (SCID or "bubble boy" disease) (5), Wiskott-Aldrich Syndrome (3) and others. Nineteen additional patients had blood cancers, with acute lymphoblastic leukemia being the most common. (The cohort with blood cancers requires longer-term endpoints and will be reported on in more detail at a later date.)

"These interim results present strong evidence that the addition of BPX-501 modified donor T cells provides important immune support and improves outcomes in patients undergoing a T-depleted haploidentical stem cell transplant," said lead investigator Dr. Franco Locatelli, Director, Department of Pediatric Hematology and Oncology, IRCCS Ospedale Pediatrico Bambino Gesù. "Historically, haplo-transplants had to be given without T cells to avoid Graft versus Host Disease, increasing the risk of deadly infections and delayed immune recovery, and relapse in patients with malignant disease. An approach that addresses these risks without elevating the GvHD risk could shift the standard of care, making haplo-sourced transplants - almost always available from a family member - an attractive option for patients. I am very happy for the patients and the families who have benefited from participation in this BPX-501 clinical trial."

The presented data show that treatment with BPX-501 is safe and well tolerated for patients with non-malignant and malignant diseases, and provides several important immune benefits compared to the clinical site's historical controls. Highlights include:

  • Safety: No adverse events associated with infusion of BPX-501 were reported. The occurrence and severity of GvHD in study subjects was generally consistent with the historical control group. There were seven instances of Grade 1 or 2 GvHD which all resolved without requiring activation of the CaspaCIDe® safety switch with rimiducid.
  • Survival: There was no transplant-related mortality (TRM) in the 37 study patients with a minimum of 30 days follow-up. In particular, for non-malignant patients, this lack of TRM (0/18) compares favorably with 9% TRM in the historical non-malignant control patients (3/33). TRM, when it occurs, typically happens early in the post-transplant period in non-malignant transplant patients, primarily due to infection.
  • Immune Reconstitution: Non-malignant patients in the trial achieved a mean improvement of approximately 40 fewer days to reach a T-cell count of 500 cells/ul, showing immune recovery was significantly faster than historical controls.
  • Time in Hospital: Non-malignant patients in the trial were discharged significantly faster from the hospital, 21 days sooner on average following HSCT, compared to historical controls. The number of patients re-hospitalized was also substantially reduced.

"It's exciting to see the progress and outcomes from this BPX-501 study that we initiated just a year ago," said Annemarie Moseley, Ph.D., M.D. Chief Operating Officer and Executive Vice President of Clinical Development at Bellicum. "We are making preparations for dialogue with the regulators in Europe and the U.S. in the first half of 2016, with the goal of defining the path to regulatory approval initially for non-malignant pediatric diseases. We look forward to the further evaluation of BPX-501 in different transplant settings, and in accumulating longer-term data to assess relevant clinical outcomes in the malignant setting."