Juno Therapeutics said Wednesday it has suspended a Phase II clinical trial of a cancer drug after two patients suffered cerebral edema earlier this week, leaving one dead and the other not expected to recover. The company’s ‘Rocket’ trial for B cell acute lymphoblastic leukemia is testing a drug it calls JCAR015.
These drugs work by extracting T cells from patients and then equipping them with chimeric antigen receptors, which then zero in on cancer cells. This first generation of CAR-Ts, which is likely to be eclipsed by early-stage efforts, has been known to trigger harsh side effects.
The cause of death in these patients was cerebral edema, or swelling in the brain. Cerebral edema was the same condition that killed three patients earlier this year and forced the company to stop the trial in this summer. Juno, at that time, had blamed the deadly reaction on one of the chemotherapy drugs that it was using to “precondition,” or prepare the patients for JCAR015. The FDA allowed Juno to restart the trial in short order, however, without the chemo drug, called fludarabine.
Juno said it has notified the Food and Drug Administration of the voluntary hold and is working with the agency and the Data and Safety Monitoring Board to determine next steps. Juno’s trials and plans for its other product candidates are not affected, the company said in a prepared statement.