FDA grants accelerated approval to Onyx's Kyprolis for treatment of multiple myeloma

Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced that the U.S. Food and Drug Administration (FDA) has granted accelerated approval of Kyprolis™ (carfilzomib) for Injection, a proteasome inhibitor, indicated for the treatment of patients with multiple myeloma who have received at least two prior therapies, including bortezomib and an immunomodulatory agent, and have demonstrated disease progression on or within 60 days of completion of the last therapy. The indication for Kyprolis is based on response rate. Currently, no data are available for Kyprolis that demonstrate an improvement in progression-free survival or overall survival.

"Today's approval is a significant milestone for Onyx and, most importantly, for patients with advanced myeloma who have few treatment options available to them," said N. Anthony Coles, M.D., President and Chief Executive Officer of Onyx Pharmaceuticals. "We deeply appreciate the hundreds of patients who participated in the Kyprolis clinical studies that led to this accelerated approval, and recognize the many clinicians across the country and researchers here at Onyx for their dedication in bringing this promising new medicine to patients. We are committed to continuing the clinical development of Kyprolis across earlier stages of multiple myeloma treatment."

The approval was based on the results of the Phase 2b 003-A1 study, a single-arm, multicenter clinical trial that enrolled 266 patients with multiple myeloma who had received a median of five prior anti-myeloma regimens. The primary efficacy endpoint was overall response (ORR) and determined by an Independent Review Committee using the International Myeloma Working Group (IMWG) criteria.  ORR was 22.9% and median response duration was 7.8 months.

Safety data were evaluated in 526 patients with relapsed and/or refractory multiple myeloma who received single-agent carfilzomib.  There were 37 deaths on study, or 7% of patients.  The most common causes of death, other than disease progression, were cardiac (5 patients), end-organ failure (4 patients), and infection (4 patients). Important warnings and precautions include cardiac arrest, congestive heart failure, myocardial ischemia; pulmonary hypertension, pulmonary complications, infusion reactions, infusion reactions, tumor lysis syndrome, thrombocytopenia, hepatic toxicity and embryo-fetal toxicity. The most common serious adverse reactions were pneumonia, acute renal failure, pyrexia, and congestive heart failure.  The most common adverse reactions (incidence of 30% or greater) observed in clinical trials of patients with multiple myeloma were fatigue, anemia, nausea, thrombocytopenia, dyspnea, diarrhea, and pyrexia.  Serious adverse reactions were reported in 45% of patients. 

"This approval provides a new treatment option for the significant unmet need that exists in patients with multiple myeloma who have progressed after use of available treatments," said Dr. David Siegel, Chief of the Division of Multiple Myeloma at John Theurer Cancer Center at Hackensack University Medical Center. "The single-agent activity of Kyprolis provides clinicians the opportunity to help these patients who until now had no effective options."