Enrollment Completed in Phase III Studies of Nexavar for Patients with Metastatic Melanoma and Liver Cancer

West Haven, CT and Emeryville, CA – May 03, 2006 – Bayer Pharmaceuticals Corporation (NYSE: BAY) and Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced the completion of patient enrollment in two randomized, double-blind Phase III clinical trials; one administering Nexavar® (sorafenib) tablets in combination with the chemotherapeutic agents carboplatin and paclitaxel in patients with advanced metastatic melanoma and another administering Nexavar as a single agent in patients with advanced hepatocellular carcinoma (HCC), or liver cancer.

“Therapy with Nexavar could potentially provide an important advancement in the treatment of these difficult diseases, and we are pleased to have reached these milestones,” said Henry Fuchs, M.D., executive vice president and chief medical officer of Onyx Pharmaceuticals. “While the studies are still ongoing and analyses will not commence until the pre-specified number of events are reached, we look forward to generating randomized data in these indications.”

Trial Designs
The company-sponsored melanoma trial is designed to evaluate the safety and efficacy of Nexavar when co-administered with chemotherapy, and has progression-free survival as its primary endpoint. Approximately 250 patients with disease progression following one previous systemic chemotherapeutic treatment (with either dacarbazine (DTIC) or temozolomide) were enrolled into the study. In addition to a standard dosing schedule of carboplatin (AUC 6) and paclitaxel (225 mg/m2), patients were randomized to receive either 400 mg of Nexavar twice daily or matching placebo. The melanoma study includes sites in the Americas, Europe, and Australia.

The Phase III study in patients with advanced HCC is designed to measure differences in overall survival, time to symptom progression and time to tumor progression of Nexavar versus placebo. Approximately 560 patients who had not received previous systemic treatment for their disease were randomized to receive 400 mg of oral Nexavar twice daily or matching placebo. The HCC study is being conducted in the Americas, Europe, and Australia/New Zealand.

About Melanoma
Cancer of the skin (nonmelanoma and melanoma skin cancers combined) is the most common type of cancer, accounting for more than 50 percent of all cancers. In some parts of the world, especially among Western countries, melanoma is becoming more common every year. In the United States, for example, the percentage of people who develop melanoma has more than doubled in the past 20 years. Melanoma accounts for about four percent of skin cancer cases but causes about 79 percent of skin cancer deaths. In 2002, about 160,000 people worldwide (about 53,000 Americans) were diagnosed with melanoma, and more than 40,000 of them (about 7,500 Americans) died from the disease. For more information on melanoma, visit the Melanoma International Foundation (MIF) web site at: www.melanomainternational.org.

About Hepatocellular Carcinoma
Hepatocellular carcinoma, also known as primary liver cancer, is the most common form of liver cancer and is responsible for 80 percent of the primary malignant liver tumors in adults. It is the fifth most common cancer in the world. In 2002, approximately 626,000 HCC cases were reported worldwide, with 15,000 cases in the United States and 53,600 in Europe. HCC is most prevalent in developing countries, particularly in East and South-east Asia, the Pacific Basin, and sub-Saharan Africa. Of the 626,000 cases worldwide, approximately 410,000 were reported in Eastern Asia (with 346,000 in China and 40,000 in Japan alone). HCC causes more than 600,000 deaths annually worldwide. The five-year relative survival rate is about seven percent.

About Nexavar
Nexavar is an oral multi-kinase inhibitor that targets both the tumor cell and tumor vasculature. In preclinical models, Nexavar targeted 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-2, VEGFR-3, PDGFR-?, KIT, and FLT-3.

Nexavar has been studied in more than 20 tumor types and in nearly 8,000 clinical trial patients. Nexavar is currently in Phase III clinical trials for the treatment of advanced hepatocellular carcinoma (HCC), or liver cancer, and metastatic melanoma, or skin cancer. A Phase III clinical trial in non-small cell lung cancer (NSCLC) was initiated in February 2006. In addition to company-sponsored trials, there are a variety of Nexavar studies being sponsored by government agencies, cooperative groups and individual investigators.

Important Safety Considerations for U.S. Patients Taking Nexavar
Based on the current, 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% for Nexavar vs. 8% for placebo and the incidence of treatment-emergent cardiac ischemia/infarction was 2.9% for Nexavar vs. 0.4% 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% for Nexavar vs. 28% 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 engaged in the development of novel cancer therapies that target the molecular basis of cancer. With its collaborators, the company is developing small molecule drugs, including Nexavar with Bayer Pharmaceuticals Corporation. For more information about Onyx’s pipeline and activities, visit the company’s web site at: www.onyx-pharm.com.

About Bayer Pharmaceuticals Corporation
Bayer Pharmaceuticals Corporation (www.bayerpharma.com) is part of the worldwide operations of Bayer HealthCare AG, a subsidiary of Bayer AG.

Bayer HealthCare AG, with sales of approximately 9.4 billion Euros in 2005, is one of the world’s leading, innovative companies in the healthcare and medical products industry. The company combines the global activities of the Animal Health, Consumer Care, Diabetes Care, Diagnostics and Pharmaceuticals divisions. Bayer Pharmaceuticals Corporation is part of the new Global Pharmaceutical Division, established January 1, 2006, which consists of the former Biological Products and Pharmaceutical Division and now comprises three business units: Hematology/Cardiology; Oncology and Primary Care. Bayer HealthCare AG employed 33,800 people worldwide in 2005.

Bayer HealthCare AG’s aim is to discover and manufacture innovative products that will improve human and animal health worldwide. The products enhance well-being and quality of life by diagnosing, preventing and treating disease.

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, 2005, 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.

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

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