US drug advisers have overwhelmingly given their backing to Onyx Pharmaceuticals' multiple myeloma drug Kyprolis.

The US Food and Drug Administration's Oncologic Drugs Advisory Committee  have voted 11-0 (with one abstention) to recommend approval of Kyprolis (carfilzomib). Onyx filed the drug for the treatment of patients with relapsed and refractory multiple myeloma who have received at least two prior lines of therapy that included a proteasome inhibitor, such as Takeda/Johnson & Johnson's Velcade (bortezomib), the same class as Kyprolis, and an immunomodulatory agent.

The Kyprolis New Drug Application is based primarily on a Phase IIb trial which evaluated 266 heavily-pretreated patients who had received at least two prior therapies, including Velcade and either thalidomide or Celgene's Revlimid (lenalidomide). About 22% of people taking the Onyx drug had some response which lasted for just under eight months.

Earlier this week, FDA staffers expressed concern about the toxicity of Kyprolis but panel member Michael Menefee of the Mayo Clinic said "I do think this drug is beneficial to this patient population given the limited therapeutic options available".

The vote was described as "a great day for the myeloma community" by the International Myeloma Foundation. The non-profit organisation noted the "powerful and emotional statements" made by patients who testified during the public comment portion of the meeting which "emphasised the unmet need and the blunt reality that without new drugs thousands of relapsing myeloma patients would die without access".

The IMF notes that the panel "seemed persuaded by the arguments and - with remarkably few questions - voted to support approval", noting that this "bodes well for upcoming reviews of additional new agents such as pomalidomide", from Celgene. It added that "the ODAC approval acknowledges that there is an unmet need, and that new options are essential and crucial to keep myeloma patients alive while we search for the cure".