Onyx Pharmaceuticals has received a fast-track designation from the US Food and Drug Administration (FDA) for its multiple myeloma drug carfilzomib and has begun a rolling submission of its new drug application (NDA) for the product.

Fast-track status, which is reserved for drugs that have the potential to treat serious diseases and fill unmet medical needs, allows for a rolling submission and review of the marketing application, as well as more frequent feedback from the FDA. Onyx said it has submitted the non-clinical section of its application and aims to complete the full submission by the middle of this year.

Onyx had originally planned to submit a full NDA by the end of 2010. However, the company ran into a delay when the FDA requested additional information about manufacturing plans after tests revealed variations in carfilzomib being produced using newly implemented manufacturing processes.

The company said at that time it was revising its timeline to predict that the product could be commercially available in 2012, but the fast-track designation could now help put things back on schedule for an earlier approval and launch.

Carfilzomib also has US orphan drug status for the multiple myeloma indication, which was granted by the FDA in 2008. The orphan drug designation, which is designed to encourage the development of drugs for diseases affecting fewer than 200,000 Americans, carries potential benefits including grant funding for clinical trials, tax breaks, and seven years of US market exclusivity.

The drug is a proteasome inhibitor being developed for the treatment of patients with relapsed and refractory multiple myeloma. The company presented positive clinical results during the American Society of Hematology meeting in December 2010.

Onyx acquired carfilzomib in 2009 when it purchased the cancer drug development company Proteolix for $276m. The drug, which had completed phase I trials at the time, was Proteolix's lead product.