‘This is a humbling experience,’ Juno CEO says
FDA has temporarily halted a Juno Therapeutics clinical study that used genetically engineered cells to treat cancer after three participants died, the company announced on Thursday.
The patients, all in their 20s, died from swelling in the brain. Two of the patients died two weeks ago, while the third died
Juno’s study used a CAR-T therapy called JCAR015 to extract the immune system T cells of adult patients with advanced acute lymphoblastic leukemia and genetically engineer the cells to attack their cancers. Patients took chemotherapy drugs to kill off their own T cells so that the genetically engineered cells could be reinfused into their bloodstreams.
Initially, Juno used only the chemotherapy drug cyclophosphamide in the study. But recently, it added another chemotherapy drug, fludarabine, to the treatment.
All three of the deaths were among the six or seven patients who have received both chemotherapy drugs, the New York Times reports. According to Juno, there have been no deaths among the 14 patients who received only cyclophosphamide, and company executives believe the problems resulted from an adverse react.
The company has asked FDA to allow the trial to proceed without using fludarabine. It is unclear whether FDA will allow the trial to proceed, with or without the chemotherapy drug. For now, FDA has put a clinical hold on the study, which prevents patients from being enrolled.
Hans Bishop, Juno’s CEO, said, “This is a humbling experience,” adding, “Clearly these therapies are potent, that’s why they offer the potential for cures. We’re still learning to use them in the safest, most efficacious way.”
A ‘setback to one of the most exciting pursuits in oncology’
Early studies using CAR-T therapy have showed promising results, and the deaths represent a “setback to one of the most exciting pursuits in oncology,” Andrew Pollack writes in the New York Times.
In other early-stage clinical trials, CAR-T therapies eliminated all traces of lymphoma and leukemia in 40 to 90 percent of patients who had no other treatment options. But the therapy also can cause a dangerous buildup of toxins from the killed tumor cells that can provoke severe, sometimes fatal side effects, including the brain swelling that killed the three study participants. Typically, steroids and other treatments are used to control the inflammation.
Otis Brawley, CMO of the American Cancer Society, said the clinical hold “is a big deal” but that the seemingly clear connection between the deaths and fludarabine may help Juno “get this back on track” (Pollack, New York Times, 7/7; Beasley, Reuters, 7/7; Herper, Forbes, 7/7).