FDA Withdraws Approval for Pepaxto Due to Ineffectiveness, Safety Concerns

Federal drug regulators have officially withdrawn approval of the multiple myeloma drug Pepaxto, indicating that it has not shown to be safe or effective in treating blood cancer.

The U.S. Food and Drug Administration (FDA) announced its final decision to withdraw approval of Oncopeptides AB’s Pepaxto multiple myeloma cancer drug in a press release issued on February 23. The decision came after the agency determined the drug did not meet clinical trial goals.

Pepaxto (melphalan flufenamide) was given accelerated approval by the FDA in February 2021, for use with low-dose dexamethasone to treat patients with reoccurring or treatment-resistant multiple myeloma, after prior therapies failed. As a post-approval requirement, the agency required the manufacturer, Oncopeptides AB, to conduct a post-marketing clinical trial known as OCEAN.

Just months after its approval, the FDA issued a Pepaxto safety alert in July 2021, warning that findings of the OCEAN clinical trial linked the drug to an increased risk of death.

The clinical trial’s findings indicated the median overall survival rate among patients taking Pepaxto was 19.7 months, compared to 25 months among those using the control treatment, pomalidomide. During the study, 48% of Pepaxto patients died.

As a result of the higher than expected mortality rate seen among those taking Pepaxto, the FDA ordered the manufacturer to suspend further enrollment in the study and all other ongoing clinical trials.

According to the FDA press release, an Oncologic Drugs Advisory Committee (ODAC) meeting was held to discuss the OCEAN trial findings in September 2022, and the ODAC voted 14 to 2 that the drug did not show favorable treatment results. The FDA notified Oncopeptides of its proposal to withdraw Pepaxto from the U.S. market in August 2023, and the manufacturer attempted to appeal the decision.

In response to the appeal, the FDA reviewed data submitted by Oncopeptides and issued a final decision to withdraw Pepaxto from the market, indicating that the OCEAN study findings do not show the drug is safe or effective in treating patients with multiple myeloma.

The decision to withdraw Pepaxto is effective immediately, and the FDA indicates it plans to issue a Federal Register notice later, announcing its decision to remove Pepaxto from its list of approved drugs.

The manufacturer indicates it will thoroughly assess the FDA’s decision in a press release issued on February 23, and will focus on selling the drug in Europe, where it has full marketing authority under the name Pepaxti.