Oncopeptides tanks, as FDA pulls Pepaxto US marketing authorization

Swedish biotech Oncopeptides (Nasdaq Stockholm: ONCO) saw its shares plunge 36% to 12.00 Swedish kronor yesterday, after it revealed that the US Food and Drug Administration (FDA) has requested a withdrawal of the US marketing authorization for its multiple myeloma drug Pepaxto (melphalan flufenamide).

Pepaxto was approved under the FDA’ accelerated approval scheme in March last year, which requires verification and description of clinical benefit in a confirmatory trial for continued approval. There has been a slew of drugs recently that have been excluded from the US market by the FDA on the failure of drugmakers to provide the necessary confirmations.

The request is based on the outcome of the confirmatory Phase III OCEAN study, which demonstrated an ITT overall survival HR of 1.1, but with significant survival result differences for both melflufen and the comparator drug pomalidomide for large relevant patient groups.