Onyx Pharmaceuticals announces delay in NDA filing for carfilzomib

Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced that it will delay its New Drug Application (NDA) filing for carfilzomib based on a recent meeting with the Chemistry, Manufacturing and Controls (CMC) review division of the U.S. Food and Drug Administration (FDA).  The FDA has requested additional CMC information related to commercial-scale manufacturing of carfilzomib.  Onyx had previously anticipated filing an NDA by the end of 2010 for accelerated approval of carfilzomib and now expects that its NDA filing for accelerated approval could occur as early as mid-year 2011.

The clinical profile of carfilzomib has not changed, and no new safety signals have been observed. The Phase 3 trials are on schedule and actively enrolling patients, and this change is not expected to impact any of the carfilzomib trials or other development plans.

In preparation for commercial-scale production, the company made manufacturing process enhancements in the production of carfilzomib, which are customary when migrating from clinical to commercial-scale manufacturing.  In a recently completed manufacturing-scale run, the company observed minor variations that are believed to be primarily related to equipment temperature variances.  In response to FDA's request, Onyx is providing the agency with additional CMC information.  Onyx has additional data and is generating more information to share as part of the ongoing dialogue with the CMC review division in preparation for an NDA filing.

"We are confident in the clinical and preclinical data package supporting the carfilzomib NDA and in our manufacturing strategy," said N. Anthony Coles, M.D., president and chief executive officer of Onyx. "We believe that by providing this supportive data, we will strengthen our NDA package, thus enabling us to bring carfilzomib to patients with multiple myeloma as quickly as possible."

The complete data set from the Phase 2b 003-A1 clinical trial of carfilzomib in patients with relapsed and refractory multiple myeloma, along with new data on carfilzomib from additional studies, will be presented at the American Society of Hematology Annual Meeting in December 2010.