FDA Lets Juno Jump Back Into T-Cell Trial, Minus One Chemo Drug

Xconomy Seattle — 

The FDA has allowed Juno Therapeutics to resume a high profile clinical trial of a cutting-edge cancer therapy less than a week after the trial was halted, Juno (NASDAQ: JUNO) announced this afternoon. The news has bumped its share price 25 percent in after-hours trading Tuesday.

The Seattle biotech firm revealed last week the recent deaths of two patients. They were receiving an experimental treatment, JCAR015, that used their own modified T cells to fight acute lymphoblastic leukemia. One more patient had died in May. All three deaths were from swelling in the brain.

Juno last week attributed the swelling to fludarabine, one of two chemotherapies that Juno was adding to the T cell treatment regimen for preconditioning. Preconditioning is the practice of dosing patients with potent chemotherapies before reintroducing the patient’s own modified T cells back into his or her body to attack the cancer.

Juno said today it could resume without fludarabine but would continue to precondition patients with cyclophosphamide, the second chemotherapy. In an interview on CNBC, Juno CEO Hans Bishop said that if the company could replicate the cyclophosphamide-only results that New York’s Memorial Sloan Kettering Cancer Center produced in a Phase 1 trial—with about 35 percent of patients reaching a long-lasting remission—it would be “an important advance” for patients who have exhausted all other options. The Phase 2 trial, dubbed “ROCKET,” is studying JCAR015 in adults who have relapsed or whose cancer has resisted treatment.

Bishop said Juno hoped to do better with another treatment, JCAR017, that’s not as far along.

Until the hold, Juno had hoped to present the study’s data to the FDA and receive a marketing approval decision in 2017. Those plans were likely delayed, Bishop said last week. It’s unclear if the company still expects a delay.