Safety Study of Gene Modified Donor T-Cells in Adults With Advanced Hematologic Malignancies

The objective is to evaluate the safety of two planned infusions of BPX-501 after partially mismatched, related HSCT with post-transplant cyclophosphamide and to evaluate the safety and efficacy of the treatment of dimerizer drug, rimiducid (AP1903), to subjects who received BPX-501 and have uncontrolled GvHD. Assuming no toxicity, enrollment will proceed sequentially for the initial 9 patients (following the 3+3 design), who will be followed for 100 days, prior to enrolling the subsequent 31 patients. Toxicity may increase the number of initial group of patients). As multiple dose levels may be administered among the first 9 (or more) patients, toxicity will be assessed on the cohort with the maximum tolerated dose (MTD). The Medical Monitoring committee will review the data with the investigators and determine whether to proceed and or implement any changes to the protocol BPX-501 contains genetically modified donor T cells that have an inducible safety switch iCasp9 suicide gene. In the event of acute GvHD, administration of rimiducid dimerizes and activates caspase 9; this activates downstream caspases, obligating cellular apoptosis within 24 hours.