Juno Therapeutics (JUNO) announced that the U.S. Food and Drug Administration (FDA) has placed a clinical hold on the Phase II clinical trial of JCAR015 in adult patients with relapsed or refractory B cell acute lymphoblastic leukemia (r/r ALL), known as the “ROCKET” trial.

The clinical hold was initiated after patients’ death last week, which followed a recent addition of fludarabine to the pre-conditioning regimen.

Juno has proposed to the FDA to continue the ROCKET trial using JCAR015 with cyclophosphamide pre-conditioning alone. In response, the FDA has requested that Juno submit, as . . .