Positive results from Onyx's carfilzomib Phase 2b 003-A1 study in relapsed and refractory multiple myeloma

Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced updated results from the Phase 2b 003-A1 study of single-agent carfilzomib, a next generation proteasome inhibitor, in patients with relapsed and refractory multiple myeloma. Carfilzomib achieved a clinical benefit rate (CBR) (minimal response or greater) in the study population of 37 percent with a duration of response (DOR) of 8.3 months.  The primary endpoint, overall response rate (ORR) (defined as partial response or greater) was 24 percent with a median duration of response (DOR) of 7.8 months.  Patients entered the study after receiving a median of five prior lines of therapy (corresponding to a median of 13 anti-myeloma agents). The median overall survival (OS) for all patients in the study, regardless of response to drug, was 15.6 months. Overall survival for the best responding patients (partial response or greater) is continuing to mature (subject to additional patient observations) and is currently 20.7 months.  These data are being presented at the upcoming 47th American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago by David Siegel, M.D., Ph.D., Division Chief for Myeloma at John Theurer Cancer Center at Hackensack University Medical Center, June 3 – 7, 2011.

Based on the full 003-A1 results, Onyx intends to submit a New Drug Application (NDA) filing for accelerated approval in the July/August timeframe.

"As expected, studies mature and results are updated with minor variability in data observed," said Ted Love, M.D., Executive Vice President, R&D and Technical Operations.  "We are particularly pleased to see the overall survival trend improving for the best responding patients.  Onyx looks forward to filing an NDA in the July to August timeframe based on the positive findings in the 003-A1 study of carfilzomib in relapsed and refractory multiple myeloma."

The most common Grade 3/4 adverse events were thrombocytopenia (29 percent), anemia (24 percent), lymphopenia (20 percent), and neutropenia (11 percent).  

Two hundred and sixty-six patients with relapsed and refractory multiple myeloma were enrolled in the study, and 257 patients were evaluable for response. The primary endpoint was ORR. Secondary endpoints included CBR, DOR, OS, and safety.

SOURCE Onyx Pharmaceuticals, Inc.