2007 Press Releases

Bayer and Onyx Submit New European Marketing Authorization Application to EMEA for Nexavar to Treat Liver Cancer

Nexavar is First Ever Drug Therapy to Demonstrate Significant Survival Benefit in Liver Cancer

Wayne, NJ and Emeryville, CA — Jun. 19, 2007

Bayer HealthCare Pharmaceuticals, Inc. (NYSE: BAY) and Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced that a Marketing Authorization Application (MAA) has been submitted by Bayer to the European Medicines Agency (EMEA) in London for the approval to market Nexavar® (sorafenib) tablets within the European Union for the treatment of hepatocellular carcinoma (HCC), a cancer of the liver. Nexavar is currently approved in more than 50 countries for the treatment of advanced kidney cancer. The companies plan to file a supplemental New Drug Application with the U.S. Food and Drug Administration for Nexavar in the treatment of liver cancer this summer.

The MAA submission is based on positive data from the international, Phase 3, placebo-controlled Sorafenib HCC Assessment Randomized Protocol (SHARP) trial which demonstrated that Nexavar extended overall survival by 44 percent in patients with HCC (HR=0.69; p-value=0.0006) versus placebo. These results were presented on June 4, 2007 at the annual meeting of the American Society of Clinical Oncology. Currently, there are no EMEA-approved drug therapies that significantly extend survival of liver cancer patients.

"Despite recent progress in cancer treatment, death rates from liver cancer continue to increase, highlighting the critical need for new therapeutic options," said Susan Kelley, MD, Vice President, Therapeutic Area Oncology, Bayer HealthCare Pharmaceuticals. "Nexavar marks a significant advance for patients with liver cancer and their families because it is the first drug therapy ever to demonstrate a significant survival benefit in liver cancer and it provides this important clinical benefit with a manageable toxicity profile."

Bayer and Onyx halted the SHARP trial in February 2007 when an independent data monitoring committee determined that the overall survival endpoint had been met. There were no significant differences in serious adverse event rates between the Nexavar and placebo-treated groups, with the most commonly observed serious adverse events in patients receiving Nexavar being diarrhea and hand-foot skin reaction.

HCC, the most common form of liver cancer, is responsible for about 90 percent of the primary malignant liver tumors in adults.1,2 It is the fifth most common cancer in the world and the third leading cause of cancer-related deaths globally.3,4 Over 600,000 new cases of HCC are diagnosed globally each year4 (about 19,000 in the United States5 and 32,000 in the European Union6), and in 2002 approximately 600,000 people (about 13,000 Americans and 57,000 Europeans) died of HCC.7

"We are executing on our vision to change the way cancer is treatedTM. With Bayer, we have demonstrated that Nexavar significantly improves the lives of people living with liver cancer in addition to those living with kidney cancer," said Hollings C. Renton, president and CEO of Onyx. "We anticipate that the strong adoption of Nexavar in liver cancer will help fuel our robust development program, which includes clinical trials studying Nexavar alone and in combination with other therapies across many different cancer types, including melanoma, non-small cell lung and breast cancer."

Nexavar's Differentiated Mechanism
Nexavar targets both the tumor cell and tumor vasculature and is the only oral multi-kinase inhibitor that does not require patients to interrupt their treatment schedule.

In preclinical studies, Nexavar has been shown to target members of two classes of kinases known to be involved in both cell proliferation (growth) and angiogenesis (blood supply) - two important processes that enable cancer growth. These kinases included Raf kinase, VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-B, KIT, FLT-3 and RET. Preclinical models have also demonstrated that Raf/MEK/ERK has a role in HCC; therefore blocking signaling through Raf-1 may offer therapeutic benefits in HCC.

Important Safety Considerations for U.S. Patients Taking Nexavar
Based on the currently approved package insert for the treatment of patients with advanced kidney cancer, hypertension may occur early in the course of therapy and blood pressure should be monitored weekly during the first six weeks of therapy and treated as needed. Incidence of bleeding regardless of causality was 15 percent for Nexavar vs. 8 percent for placebo and the incidence of treatment-emergent cardiac ischemia/infarction was 2.9 percent for Nexavar vs. 0.4 percent for placebo. Most common treatment-emergent adverse events with Nexavar were diarrhea, rash/desquamation, fatigue, hand-foot skin reaction, alopecia, and nausea. Grade 3/4 adverse events were 38 percent for Nexavar vs. 28 percent for placebo. Women of child-bearing potential should be advised to avoid becoming pregnant and advised against breast-feeding. In cases of any severe or persistent side effects, temporary treatment interruption, dose modification or permanent discontinuation should be considered.

For U.S. Nexavar prescribing information, visit www.nexavar.com or call 1.866.NEXAVAR (1.866.639.2827).

About Onyx Pharmaceuticals, Inc.
Onyx Pharmaceuticals, Inc. is a biopharmaceutical company developing innovative therapies that target the molecular mechanisms that cause cancer. The company is developing Nexavar®, a small molecule drug, with Bayer Pharmaceuticals Corporation. Nexavar is approved for the treatment of advanced kidney cancer in more than 50 countries. For more information about Onyx's pipeline and activities, visit the company's web site at: www.onyx-pharm.com.

About Bayer HealthCare
Bayer HealthCare Pharmaceuticals Inc. is the U.S.-based pharmaceuticals unit of Bayer HealthCare LLC, a division of Bayer AG. One of the world's leading, innovative companies in the healthcare and medical products industry, Bayer HealthCare combines the global activities of the Animal Health, Consumer Care, Diabetes Care, and Pharmaceuticals divisions. In the US, Bayer HealthCare Pharmaceuticals comprises the following business units: Women's Healthcare, Diagnostic Imaging, Specialized Therapeutics, Hematology/Cardiology and Oncology. The company's aim is to discover and manufacture products that will improve human health worldwide by diagnosing, preventing and treating diseases.

About Bayer Schering Pharma AG, Germany
Bayer Schering Pharma is a worldwide leading specialty pharmaceutical company. Its research and business activities are focused on the following areas: Diagnostic Imaging, Hematology/Cardiology, Oncology, Primary Care, Specialized Therapeutics and Women's Healthcare. With innovative products, Bayer Schering Pharma aims for leading positions in specialized markets worldwide. Using new ideas, Bayer Schering Pharma aims to make a contribution to medical progress and strives to improve quality of life.

Forward Looking Statements
This news release contains forward-looking statements based on current assumptions and forecasts made by Bayer Group management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in Bayer's public reports filed with the Frankfurt Stock Exchange and with the U.S. Securities and Exchange Commission (including its Form 20-F). Bayer assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments.

This news release also contains "forward-looking statements" of Onyx within the meaning of the federal securities laws. These forward-looking statements include without limitation, statements regarding the timing, progress and results of the clinical development, regulatory processes, and commercialization efforts of Nexavar. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated. Reference should be made to Onyx's Annual Report on Form 10-K for the year ended December 31, 2006, 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.

Nexavar® (sorafenib) tablets is a registered trademark of Bayer Pharmaceuticals Corporation.
"Change the way cancer is treated" is a registered trademark of Onyx Pharmaceuticals.

References
1 World Health Organization. Hepatitis B. Available at: http://www.who.int/csr/disease/hepatitis/whocdscsrlyo20022/en/. Accessed April 10, 2007.
2 Penn State Milton S. Hershey Medical Center College of Medicine. Malignant Hepatoma. Available at: http://www.hmc.psu.edu/healthinfo/m/malignanthepatoma.htm. Accessed April 10, 2007.
3 World Health Organization. Estimates by WHO Region: Incidence. Available at: http://www.who.int/healthinfo/statistics/gbdwhoregionincidence2002.xls. Accessed April 10, 2007.
4 International Agency for Cancer Research. GLOBOCAN 2002. Available at: http://www-dep.iarc.fr. Accessed April 23, 2007.
5 Jemal A et al. CA Cancer J Clin. 2007;57:43-66.
6 International Agency for Cancer Research. EUCAN 1998. Available at: http://www-dep.iarc.fr/eucan/eucan.htm. Accessed April 26, 2007.
7 Ferlay J, et al., GLOBOCAN 2002. Cancer Incidence, Mortality and Prevalence Worldwide. IARC CancerBase No.5, Version 2.0. IARCPress, Lyon, 2004. Available at: http://www-dep.iarc.fr. Accessed April 10, 2007.