CAR-T Deaths Cannot Be Good

Late yesterday afternoon, Matthew Herper broke the news that Juno Therapeutics had had their CAR-T leukemia trial put on hold after three patient deaths. That’s bad news no matter how you look at it, even for their competitors.

It’s too early to say for sure if Juno will be slowed in its path to market. In an interview, Bishop and Juno chief financial officer Steven Harr said that they think they understand why the deaths occurred, that they think they can get the trial back on track quickly, and that they do not think this will affect the development of the other 8 CART programs the company is pursuing.

Bishop says that the culprit appears to be a new drug, the chemotherapy fludarabine, that Juno recently added to the trial, called ROCKET. In the CART treatment, patients are first given a chemo cocktail that kills their existing T-cells. This gives the new T-cell, genetically re-engineered to attack cancer, room to grow. Juno has previously presented work showing that adding a drug called fludarabine to the chemotherapy makes the CART...