FDA Places Holds on Two Clinical Trials for Atezolizumab

The U.S. Food and Drug Administration (FDA) placed partial holds on two clinical trials evaluating the anti–PD-1 agent atezolizumab in patients with relapsed or refractory myeloma, following safety concerns about other PD-1 and PD-L1 inhibitors under investigation.

The partial clinical hold affects phase Ib and phase Ib/II trials of atezolizumab in combination with lenalidomide or pomalidomide for relapsed or refractory multiple myeloma. Patients currently enrolled who are receiving clinical benefit are allowed to continue in the trials, but no new enrollees will be accepted.

The FDA decided to place these trials on partial hold based on safety concerns seen in clinical trials of other PD-1 inhibitors in myeloma. In July 2017, the FDA ordered the discontinuation of three clinical trials of pembrolizumab after excessive deaths were reported. Durvalumab combination trials were recently placed on hold by the FDA for similar concerns regarding the combination of anti–PD-1/PDL-1 agents and immunomodulatory agents.

In a press release to investors, Roche, the manufacturers of atezolizumab, stated they have not seen evidence of increased death or serious events related to the combination treatment.

In August, the FDA’s Center for Drug Evaluation and Research Director Janet Woodcock, MD, released a statement reiterating the safety concerns associated with pembrolizumab, noting that “the agency is working with sponsors of other similar cancer drugs, known as PD-1/PD-L1 inhibitors, to examine other trials in which these drugs are being studied in combination with other drugs, known as immunomodulatory agents, and in which they’re being studied in combination with other classes of drugs in hematologic malignancies.”

Sources: Roche press release, September 15, 2017; FDA press release, August 31, 2017.