Shares of Juno Therapeutics Inc. (JUNO) were up more than 25% in after-hours trading on Tuesday after the biopharmaceutical company said the Food and Drug Administration had removed the clinical hold on the Phase 2 clinical trial of JCAR015, aimed at adult patients with relapsed or refractory B cell acute lymphoblastic leukemia.

The announcement that Juno will resume the trial came five days after the Seattle company said the FDA had halted the trial after two patient deaths, which followed the recent addition of fludarabine to the pre-conditioning regimen. News of the clinical hold sent the company's shares diving. The stock closed at $27.81 on July 8, down nearly 32%.

On a conference call on July 7, Juno said the safety issues tied to JCAR015 hadn't been observed in the rest of its cellular therapy pipeline.

On Tuesday, Juno said that under the revised protocol, the trial will continue enrollment using JCAR015 with cyclophosphamide pre-conditioning only.

Shares were changing hands at $34.90 in after-hours trading on Tuesday.

Juno started a Phase 2 trial of JCAR015 in the third quarter of 2015.

The company is developing cell-based cancer immunotherapies based on its chimeric antigen receptor and high-affinity T cell receptor technologies.