2007 Press Releases

Bayer and Onyx Submit Supplemental New Drug Application for Nexavar to Treat Liver Cancer

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

WAYNE, N.J. and EMERYVILLE, Calif. — Jun. 27, 2007

Bayer HealthCare Pharmaceuticals Inc. (NYSE: BAY) and Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced that a Supplemental New Drug Application (sNDA) for Nexavar® (sorafenib) tablets has been submitted to the U.S. Food and Drug Administration (FDA) for the treatment of patients with hepatocellular carcinoma (HCC), the most common form of liver cancer. Nexavar is currently approved in more than 50 countries for the treatment of advanced kidney cancer. The companies also confirmed that they are planning a company- sponsored Phase 3 study of Nexavar in the adjuvant treatment of HCC following the complete removal of early stage liver cancer.

The sNDA 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=0.0006) versus placebo. There were no significant differences in serious adverse event rates between the Nexavar and placebo-treated groups with the most commonly observed adverse events in patients receiving Nexavar being diarrhea and hand-foot skin reaction. Currently, there are no FDA-approved drug therapies that significantly extend survival of patients with liver cancer.

"These results are particularly meaningful considering that death rates from liver cancer continue to increase," said Susan Kelley, M.D., vice president, Therapeutic Area Oncology, Bayer HealthCare Pharmaceuticals. "After more than 100 clinical studies of many agents over three decades, Nexavar is the first drug therapy to demonstrate a significant survival benefit for patients with HCC, and, if approved, may fulfill a serious unmet need with a manageable toxicity profile."

HCC, the most common form of liver cancer, is responsible for about 90 percent of the primary liver cancers in adults.(1,2) It is the fifth most common cancer in the world(3) and the third leading cause of cancer-related deaths globally.(4) Over 600,000 cases of HCC are diagnosed globally each year(4) (about 19,000 in the United States(5) and 32,000 in the European Union(6)) and in 2002 approximately 600,000 people (about 13,000 Americans and 57,000 Europeans) died of HCC.(7)

"This filing exemplifies our commitment to providing valuable therapeutic options for significant unmet needs in cancer treatment," said Hank Fuchs, M.D., executive vice president and chief medical officer of Onyx. "We believe that Nexavar will become the reference standard of care in HCC, and will help advance our 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. 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% 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 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.

References
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