Updated results from the Phase IIb 003-A1 study of single-agent carfilzomib, a next generation proteasome inhibitor, in patients with relapsed and refractory multiple myeloma,shows that overall survival in “best responding patients” is trending in excess of 20 Months.
Multiple myeloma is the second most common hematologic cancer and results from an abnormality of plasma cells, usually in the bone marrow. In the United States, more than 50,000 people are living with multiple myeloma and approximately 20,000 new cases are diagnosed annually. Worldwide, more than 180,000 people are living with multiple myeloma and approximately 86,000 new cases are diagnosed annually.
Carfilzomib achieved a clinical benefit rate (CBR) with a minimal response or greater in the study population of 37% with a duration of response (DOR) of 8.3 months.
The full data set of the Pahse IIb 003-A1 results will be 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.
The primary endpoint, overall response rate (ORR), defined as partial response, was 24% with a median duration of response (DOR) of 7.8 months. Patients entered the study after receiving a median of 5 prior lines of therapy, which corresponds 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.
Based on the results, Onyx Pharmaceuticals, Inc, the manufacturer of the trial drug, 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%), anemia (24%), lymphopenia (20%), and neutropenia (11%).
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.
For more information:
 National Cancer Institute, Surveillance Epidemiology and End Results, 2007 Facts and Figures
 International Agency for Research on Cancer, GLOBOCAN 2002 database.