Two patient deaths in a Juno Therapeutics Inc. mid-stage clinical trial, coming on the heels of patient deaths in the same trial this summer, have caused Juno to put the trial on hold and re-evaluate its next steps.
The news, as with the last set of patient deaths, hit the company’s stock hard, with shares plummeting 26.7% in morning trade Wednesday.
The company’s JCAR015 drug is intended for relapsed or refractory acute lymphoblastic leukemia, which spreads and progresses quickly. Patients whose cancers come back after treatment have few to no options.
Both patients received treatment last week, developed a brain trauma called cerebral edema earlier this week and have subsequently died, Juno said, noting that it is a “rare but potentially fatal complication” of this type of cancer therapy.
After patients in the trial died this summer, Juno attributed the deaths to the chemotherapy drug fludarabine in combination with its JCAR015 drug. The trial restarted in early August without fludarabine as part of the chemotherapy regimen, which the company said it still thinks was the correct move.
“We noted at that time that more than one factor may have contributed to these events,” with fludarabine being “the most likely and most appropriately modifiable factor,” said Mark Gilbert, Juno’s chief medical officer. “We did not expect the removal of fludarabine to eliminate entirely the risk of neurotoxicity or cerebral edema.”
See: Juno Therapeutics plummets 30% in pre-market trade after two patient deaths
Juno said it’s too early to know what happens next with the trial, a decision that has to be made along with the Food and Drug Administration and the Data and Safety Monitoring Board, an independent expert advisory group.
Related: Analysts say Juno’s stock tumbles shouldn’t spill over to Bluebird, Kite Pharma shares
“All options remain on the table,” including moving forward with the trial, beginning a new study, or ending the program, said Hans Bishop, Juno’s chief executive officer, president and director. He emphasized that these patients “have virtually no other options and have a highly lethal disease.”
The drug is part of a class of CAR-T therapies, a buzzed-about space which a recent Leerink report described as having positive “but very incremental” research results.
Juno said its other product candidates targeting the B Cell Specific Antigen CD19 won’t be affected.
Shares have dropped 50.2% year-to-date, compared with a 7.6% rise in the S&P 500SPX, -0.28% Shares of Bluebird Bio Inc. BLUE, -5.43% and Kite Pharma Inc.KITE, -2.16% also dropped in morning trade Wednesday, though analysts said the companies — which are developing a similar class of cancer treatment — should recover.