FDA warns public over Keytruda myeloma combo risks in wake of Merck trial deaths

Last month, following deaths in two Keytruda trials, the FDA halted the pair of Merck studies. And now, it’s warning the public, health care professionals, clinical investigators and others about what’s at stake.

Thursday, the agency issued a statement detailing the risks associated with pairing Keytruda with chemotherapy dexamethasone and either Celgene’s Revlimid or Pomalyst as treatment for multiple myeloma. Docs and patients using any of the meds should report any adverse events or side effects to the FDA, regulators said.

In a statement, Merck stressed that Keytruda is not approved for multiple myeloma and that the FDA's communication doesn't apply to patients taking the med for its approved uses, including those in lung cancer, melanoma and head and neck cancer.

"Merck will continue to work with the FDA to evaluate the data from these studies. Patient safety remains Merck’s primary concern," a spokeswoman added.

RELATED: Trial deaths frustrate Merck's bid to pair Keytruda with Celgene's myeloma stars

The FDA first jumped into the situation in June, halting enrollment for trials Keynote-183 and Keynote-185 after receiving trial-death info from an independent data-monitoring committee. The following month, after a data review that signaled the Keytruda regimens in question increased patients’ risk of death, the agency discontinued the studies altogether.

As regulators noted, researchers are currently examining Keytruda in other studies, and other PD-1/PD-L1 cancer drug combos are going on, too.

The FDA will be working directly with sponsors of Keytruda and other PD-1/PD-L1 cancer drugs, as well as clinical investigators conducting clinical trials in patients with multiple myeloma, to determine the extent of the safety issue,” the agency said in a statement, noting that it would “communicate any new information to the public as soon as it is able.”

RELATED: Keytruda fail 'small beans' for Merck, bigger riddle for immuno-oncology scorekeepers

Myeloma isn’t the only arena in which Keytruda hit a July snag. Late in the month, the high-flying therapy missed its survival mark in a head and neck cancer trial, a performance that confounded industry watchers.

The therapy still has the lead in the all-important lung cancer space, though, and that's not likely to change any time soon. Merck boasts both solo and combo approvals for Keytruda in the frontline setting, and its rivals' attempts to score those nods have both fallen short.