2009 Press Releases

Carfilzomib Safety Data from Ongoing Phase 2b Pivotal Trial in Relapsed and Refractory Multiple Myeloma Show Promising Safety and Tolerability

Pivotal Trial Fully Enrolled – Full Data Anticipated in 2010

New Orleans, LA. — Dec. 06, 2009

Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced updated safety data from the pivotal Phase 2b 003-A1 study, known as the 003 trial, demonstrating that carfilzomib is well-tolerated in heavily pre-treated relapsed and refractory multiple myeloma patients. These data were presented today at the ASH/ASCO Joint Symposium at the 51st annual meeting of the American Society of Hematology (ASH) in New Orleans. Enrollment in this trial is complete (n=269), and full results, expected in 2010, could support a potential new drug application (NDA) filing by year-end 2010.

“These results show that carfilzomib is well-tolerated and can be administered at a full dose over a long period of time even in a very sick patient population for whom all available treatment options have been exhausted and who have multiple comorbidities,” said lead investigator Sundar Jagannath, M.D., chief of the Multiple Myeloma Program, Bone Marrow and Blood Stem Cell Transplantation at St. Vincent's Comprehensive Cancer Center in New York. “We look forward to the full data from this trial next year.”

Dr. Jagannath also presented results from the Phase 2 003-A0 study, which recruited patients whose myeloma had relapsed from two or more prior therapies and was refractory to their previous therapy. This study is the lead-in study for the current Phase 2b registrational trial in the same population. Data from this study was initially presented at the American Society for Clinical Oncology (ASCO) annual meeting in June 2009. Patients in the study had a median of five prior therapies. Previously presented efficacy data from 39 evaluable patients in the 003-A0 pilot study included an 18 percent overall response rate (partial response or better) and a 26 percent clinical benefit rate (minor response or better), median time to tumor progression of 5.1 months and a median of 7.4 months response duration.

Based on the emerging safety profile, the 003-A0 protocol was amended in 2008 to permit increased dosing of up to 27 mg/m2. The protocol was also expanded into the 003-A1 Phase 2b trial, enrolling 269 patients with relapsed and refractory myeloma and a dose escalation from 20 mg/m2 to 27 mg/m2 after one cycle. The primary endpoint for the Phase 2b 003-A1 pivotal study is overall response rate, and secondary endpoints include clinical benefit response, duration of response, progression-free survival, time-to-progression, overall survival and safety.

Dr. Jagannath presented new safety data on 141 patients in the 003-A1 trial, showing that carfilzomib was well tolerated at the 27 mg/m2 dose. Grade 3/4 hematologic events included anemia (13.5 percent), thrombocytopenia (16.3 percent), neutropenia (3.5 percent), and febrile neutropenia (0.7 percent). The rate of grade 3/4 peripheral neuropathy was 0.7 percent. The regimen was well tolerated with prolonged administration of more than 12 cycles (48 weeks) in approximately 10% of patients, and no clinically significant cumulative toxicities have been noted to date. Both portions of the trial are being conducted in collaboration with the Multiple Myeloma Research Consortium.

Investor Teleconference
Principal investigators will discuss data presentations surrounding carfilzomib in relapsed or refractory multiple myeloma, as featured at ASH. The webcast event will begin at 9:00 a.m. CT/10:00 a.m. ET on December 7, 2009. The live webcast will be available at:

http://www.onyx-pharm.com/view.cfm/32/Event-Calendar

or by dialing 847-413-3362 and using the passcode 25914947. A replay of the presentation will be available on the Onyx website or by dialing 630-652-3044 and using the passcode 25914947 later in the day. The replay will be available on the Onyx website through January 7, 2010.

About Carfilzomib
Carfilzomib is a selective, next generation proteasome inhibitor that has shown encouraging results in a broad clinical trial program in multiple myeloma. Carfilzomib is currently undergoing evaluation as a single agent in multiple Phase 2 and Phase 1 clinical trials in relapsed or refractory multiple myeloma. These trials include a Phase 2b monotherapy study in patients with relapsed, refractory multiple myeloma, the pivotal trial that could support a new drug application (NDA) filing by the end of 2010. Carfilzomib is also being evaluated in advanced solid tumors.

About Multiple Myeloma
Multiple myeloma (MM) 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 MM and approximately 20,000 new cases are diagnosed annuallyi. Worldwide, more than 180,000 people are living with MM and approximately 86,000 new cases are diagnosed annuallyii.

About Onyx Pharmaceuticals, Inc.
Onyx Pharmaceuticals, Inc. is a biopharmaceutical company committed to improving the lives of people with cancer. The company, in collaboration with Bayer HealthCare Pharmaceuticals, Inc., is developing and marketing Nexavar® (sorafenib) tablets, a small molecule drug that is currently approved for the treatment of liver cancer and advanced kidney cancer. Additionally, Nexavar is being investigated in several ongoing trials in a variety of tumor types. Beyond Nexavar, Onyx has established a development pipeline of anticancer compounds at various stages of clinical testing, including carfilzomib, a next-generation proteasome inhibitor, that is currently being evaluated in multiple clinical trials for the treatment of patients with relapsed or relapsed/refractory multiple myeloma and solid tumors. ONX 0801, a targeted alpha-folate inhibitor, is currently in Phase 1 testing. For more information about Onyx, visit the company's website at www.onyx-pharm.com.

Nexavar® (sorafenib) tablets is a registered trademark of Bayer HealthCare Pharmaceuticals.

Forward Looking Statements
This news release contains “forward-looking statements” of Onyx within the meaning of the federal securities laws. These forward-looking statements include without limitation, statements regarding the anticipated benefits of the acquisition of Proteolix and the timing, progress and results of the clinical development, safety, regulatory processes, commercialization efforts or commercial potential of carfilzomib. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including the risk that Proteolix’s operations will not be integrated successfully into Onyx’s, the risk that Onyx may not realize the anticipated benefits of the acquisition and risks related to the development and commercialization of pharmaceutical products. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Reference should be made to Onyx’s Annual Report on Form 10-K for the year ended December 31, 2008, filed with the Securities and Exchange Commission under the heading “Risk Factors” and Onyx’s Quarterly Reports on Form 10-Q for a more detailed description of such factors. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date of this release. Onyx undertakes no obligation to update publicly any forward-looking statements to reflect new information, events, or circumstances after the date of this release except as required by law.

 

 

iNational Cancer Institute, Surveillance Epidemiology and End Results, 2007 Facts and Figures
iiInternational Agency for Research on Cancer , GLOBOCAN 2002 database