EMERYVILLE, Calif., July 26 /PRNewswire-FirstCall/ -- Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced positive top-line results from the Phase 2b 003-A1 study of single-agent carfilzomib, a selective, next generation proteasome inhibitor, in patients with relapsed and refractory multiple myeloma. In an independent review of the data, carfilzomib achieved an overall response rate (partial response or greater) of 24 percent and a median duration of response of 7.4 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. The clinical benefit rate (minimal response or greater) in the study population was 36 percent. Carfilzomib was well-tolerated and there were no new or unexpected toxicities observed. Full results of the trial will be presented at an upcoming scientific meeting. Based on these results, Onyx is continuing discussions with the U.S. Food and Drug Administration (FDA) regarding next steps in filing a new drug application (NDA) for carfilzomib, which the company expects to submit by year-end 2010 for potential accelerated approval in the U.S.
"Despite recent advances in treating multiple myeloma, all patients eventually relapse. The unmet medical need remains great, as the outlook for patients with relapsed and refractory disease is grim," said Michael G. Kauffman, M.D., Ph.D., Chief Medical Officer of Onyx Pharmaceuticals. "According to a study from the International Myeloma Working Group, patients, such as those enrolled in the 003-A1 study, can expect to respond to therapy only 11 percent of the time and survive f