The FDA has issued a rare warning about the multiple myeloma drug Pepaxto (melphalan flufenamide), saying a recent confirmatory trial showed an increased risk of death.

The confirmatory OCEAN trial was evaluating Pepaxto with dexamethasone to treat patients with multiple myeloma, said FDA. The drug’s manufacturer, Oncopeptides AB, was required to conduct the trial as a postapproval requirement under the accelerated approval program.

The FDA noted that there were 117 deaths, representing 48 percent of 246 participants in the melphalan flufenamide arm of the OCEAN trial, compared with 108 deaths, representing 43 percent of the 249 patients in the pomalidomide control arm.

Due to the detrimental effect on overall survival in the confirmatory trial, the FDA said it is requiring the manufacturer suspend enrollment in the trial. The agency has also suspended enrollment in other ongoing Pepaxto clinical trials.