Onyx Pharmaceuticals announced positive complete results from the Phase 2b (003-A1) study of single-agent carfilzomib in patients with relapsed and refractory multiple myeloma. The 003-A1 study was an open-label, single-arm trial. It evaluated 266 heavily-pretreated patients with relapsed and refractory multiple myeloma whose disease was refractory to their last treatment regimen and who had received at least two prior therapies, including bortezomib, either thalidomide or lenalidomide, an alkylating agent, glucocorticoids and an anthracycline. Refractory disease was defined as less than or equal to 25% response or progression during therapy, or progression within 60 days after completion of therapy. Patients received carfilzomib at 20mg/m2 for the first cycle followed by 27mg/m2 thereafter for up to 12 cycles. Patients who completed the 12 cycles were eligible to enter an extension study. Responses and progression were determined according to the International Myeloma Working Group (IMWG) criteria.

Carfilzomib achieved an overall response rate (ORR) (partial response or greater) of 24.1% and a median duration of response (DOR) of 8.3 months in patients who entered the study after receiving a median of five prior lines of therapy (corresponding to a median of 13 anti-myeloma agents) and whose disease was refractory to their last therapeutic regimen. In addition, patients enrolled in the study had progressive disease upon entering the trial. The clinical benefit rate (CBR) (minimal response or greater) in the study population was 34.2%.  The median overall survival (OS) was 15.5 months. Overall survival for responding patients (greater than or equal to minimal response) has not yet been reached; however, based on current data is expected to exceed 19 months

Carfilzomib is a selective, next-generation proteasome inhibitor that is being investigated in a broad clinical trial program in multiple myeloma.

For more information call (510) 597-6500 or visit www.onyx-pharm.com.