The “ROCKET” trial for adult patients with relapsed or refractory B cell acute lymphoblastic leukemia (r/r ALL), was put on hold last Wednesday following the deaths of two patients.
As Outsourcing-Pharma.com previously reported, the company submitted a “Complete Response to the Clinical Hold,” earlier this week, which proposed that Juno be able to continue the trial without fludarabine.
Under the revised protocol, the trial will continue enrollment using JCAR015 with only cyclophosphamide pre-conditioning.
Dr. Mark Osborn, Assistant Professor, Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, commented:
“These events show the potential risks for CAR-T therapies utilizing vectors that mediate sustained expression that may be magnified in combinatorial chemotherapy regimens.”
Moving forward, Osborn said that improved cellular therapies with optimized vector doses, expression patterns, and cooperative activity in the presence of chemo therapeutic agents “will aid in mitigating side effects and achieving complete responses.”
Dr. Stephan Grupp, Novotny Professor of Pediatrics, University of Pennsylvania Perelman School of Medicine told us, "many patients have gotten fludarabine as part of their preconditioning regimen for CAR T cells, so I doubt this event calls the use of this drug into broad question.
"Unless there are clinical events like this on other trials, I think the trend will be to continue to use it," he added.
Grupp also said that he doesn't think the issue is likely to have a significant impact on the development of the CAR-T field. "I think the rapid lifting of the hold suggests this as well," he added.