2009 Press Releases

Onyx Pharmaceuticals to Webcast Analyst Briefing on Development Program

Emeryville, CA. — Dec. 10, 2009

Onyx Pharmaceuticals, Inc. (NASDAQ: ONXX) today announced that it will host an Analyst Briefing on December 17, 2009 at 8:30 a.m. ET.

The briefing, hosted by Onyx management, will provide an overview of its development program and feature presentations on multiple tumor types by external clinical investigators and members of management.

The live webcast, to begin at 8:30 a.m. ET, will be available on the Onyx website at:

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

A replay of the webcast will be available on the Onyx website through December 31, 2009.

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, and ONX 0801, a targeted alpha-folate inhibitor, 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.