Oncopeptides gets EU nod for myeloma drug Pepaxti ahead of US adcomm

The European Commission has approved Oncopeptides' Pepaxti in combination with dexamethasone for multiple myeloma patients with so-called triple class refractory disease – in other words those who don't respond to all three of the major classes of treatment for the blood cancer.

The approval means that Pepaxti (melphalan flufenamide) can now be used as a rescue therapy for adults with multiple myeloma who have previously failed treatment with at least one proteasome inhibitor, one immunomodulatory agent, and one anti-CD38 monoclonal antibody.

The endorsement of the drug's efficacy and safety comes at a good time for the Swedish biotech, just a month before the drug, known as Pepaxto in the US, will have its safety reviewed by an FDA advisory committee after being withdrawn from sale there last year.

The peptide-drug conjugate got accelerated approval from the FDA in February 2021 as a fifth-line therapy for multiple myeloma based on data from the phase 2 HORIZON study, but Oncopeptides voluntarily withdrew the drug from sale a few months later.

Its phase 3 follow-up study – called OCEAN – showed superior progression-free survival (PFS) for Pepaxti plus dexamethasone compared to Bristol-Myers Squibb's Pomalyst (pomalidomide) plus dexamethasone in patients who received two to four prior lines of therapy.

However, overall survival favoured the Pomalyst arm by around 10%, leading the FDA to ask for a partial clinical hold on the study and eventually Oncopeptides' decision to pull the drug in October 2021, and shutter its business operations in the US.

In January, the biotech rescinded the letter requesting voluntary withdrawal of Pepaxto after "further review and analyses of the heterogenous overall survival data from…OCEAN and other relevant trials."

It said it would not market the drug until it had agreed with the FDA on the interpretation of the data – which will be discussed at an advisory committee meeting on 22 September.

EU approval of Pepaxti has been granted on the back of the HORIZON and OCEAN studies, giving a lift to the drug just before FDA advisors look at the data, and Oncopeptides says it now plans to launch the drug in Germany before the end of the year ahead of an EU-wide rollout.

It also provides a much-needed new treatment option for triple-refractory multiple myeloma, who have no defined treatment options – limited mainly to conventional chemotherapy, a salvage stem cell transplant or repeating prior treatments – and desultory survival chances.