Safety Study of Gene Modified Donor T-cells Following TCRαβ+ Depleted Stem Cell Transplant

This study will evaluate pediatric patients with malignant or non-malignant blood cell disorders who are having a blood stem cell transplant depleted of T cell receptor (TCR) alfa and beta cells that comes from a partially matched family donor. The study will assess whether immune cells, called T cells, from the family donor, that are specially grown in the laboratory and given back to the patient along with the stem cell transplant can help the immune system recover faster after transplant. As a safety measure these T cells have been programmed with a self-destruct switch so that they can be destroyed if they start to react against tissues (Graft versus host disease).

This is a Phase I/II study evaluating the safety and feasibility of BPX-501 T cells infused after partially mismatched, related, TCR alpha beta T cell depleted hematopoietic stem cell transplant (HSCT) in pediatric patients. The purpose of this clinical trial is to determine whether BPX-501 infusion can enhance immune reconstitution in those patients with hematologic disorders, with the potential for reducing the severity and duration severe acute graft versus host disease (GvHD). The trial will also evaluate the treatment of GvHD by the infusion of dimerizer drug (AP1903/rimiducid) in those subjects who present with GVHD who progress or do not respond to standard of care treatment.