Bringing a new medical therapy to market is rarely a straightforward task, as a biotech company called Juno Therapeutics learned firsthand.  Juno specializes in CAR-T therapy, which uses genetic engineering to teach a patient’s own immune system to destroy cancer cells. Unfortunately, 3 of the 129 patients who had received this treatment in a clinical trial recently died from excessive brain swelling, prompting the FDA to halt the trial earlier this month.  Only three days later, however, the FDA lifted the hold.

A brief look into the mechanics of the clinical trial explains why Juno benefited from one of the shortest holds in FDA history.  Several patients who received CAR-T therapy were also given already-approved chemotherapy drugs in an attempt to increase the overall efficacy of the treatment.  The three patients who died were all given a drug called fludarabine, which had previously been implicated in cases of fatal brain swelling, so Juno simply proposed to stop administering it.  The FDA agreed that fludarabine was the most probable cause of death and allowed the trial to continue; if it had disagreed, the trial would have received much more scrutiny and may have been shut down.

Now that the dust has begun to settle, Juno’s roller coaster of a week appears to have been a net positive for CAR-T therapy: the FDA is confident enough in CAR-T to allow clinical trials from multiple companies to take place.  In a field where frontline therapies can kill patients, good news like this carries even more weight.

Acknowledgments: Many thanks to Enrique Garcia-Rivera, a graduate student in the Biological and Biomedical Sciences Program at Harvard University, for providing his expertise and commentary on the topic.

Managing Correspondent: Christopher Gerry

Media Coverage: Juno Halts Cancer Trial Using Gene-Altered Cells After 3 Deaths – The New York Times; Juno Therapeutics Cancer Trial Resumes, Pushing CAR-T Stocks Higher – Investor’s Business Daily