After trials halted, FDA issues warning on off-label use of the drug.
After a string of recent approvals, the FDA has issued an alert on the use of Keytruda (pembrolizumab) for the treatment of multiple myeloma-a treatment for which it is not approved.
Currently, Keytruda is indicated for: melanoma, lung cancer, head and neck cancer, classical Hodgkin lymphoma, urothelial carcinoma, and microsatellite instability-high (MSI-H) Cancer. In the last year alone, the drug has received six separate approvals.
However, the seventh approval remains elusive for the drug. A series of recent trials looked into the use of Keytruda in patients with multiple myeloma, but those were halted after safety concerns in late June/early July. As part of the alert, the FDA released information from those drug trials.
In one trial of 249 patients, there were 29 deaths of patients taking Keytruda compared with 21 in the control group, a 50% greater risk of death. In that same trial, the objective response rate was 34% for those taking Keytruda compared to 40% in the control group, along with an 18% increase in severe toxicity and a 23% increase in serious adverse events.
In a second trial of 301 patients, there were 19 deaths for patients on Keytruda compared with 9 in the control group. There was just a 2% difference in objective response rates between the Keytruda and control groups (64% vs 62%, respectively), but a 22% increase in severe toxicity and a 15% increase in serious adverse events.
The alert does not apply to patients taking Keytruda for its approved indications, only for the possible combination of Keytruda and dexamethasone and an immunomodulatory agent (lenalidomide or pomalidomide) for the treatment of patients with multiple myeloma.
Janet Woodcock, MD, Director for the FDA Center for Drug Evaluation and Research said in a statement that the alert “underscores the importance of why new therapies are thoroughly studied to ensure the benefits of taking them outweigh the risks to patients, and we will continue to aggressively monitor clinical trials to ensure patients are protected when safety concerns arise.”