Updated Overall Survival Analysis Presented on Nexavar Phase III Trial

Abstract # 4524

Atlanta, GA — Jun. 05, 2006

Bayer Pharmaceuticals Corporation (NYSE: BAY) and Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today reported that Dr. Tim Eisen provided an update on the Nexavar® (sorafenib)
tablets Phase III trial in patients with advanced renal cell carcinoma (RCC), or kidney cancer, during the 42nd Annual Meeting of the American Society of Clinical Oncology (ASCO) in Atlanta, GA.  Dr. Eisen is the consultant medical oncologist at The Royal Marsden Hospital in London, United Kingdom.  The updated analysis confirmed that overall survival was longer for Nexavar than for placebo patients.

The updated data showed a continued improvement in overall survival (OS) of 19.3 months for Nexavar patients versus 15.9 months for placebo patients (p=0.015, hazard ratio 0.77) despite the fact that 48% of placebo patients “crossed over” to Nexavar.  Dr. Eisen also reported OS of 19.3 months for Nexavar vs.14.3 months for placebo (p=0.010, hazard ratio 0.74) after censoring the placebo patients.  These data, while they did not reach the pre-specified result required to stop the OS analysis early, suggest a favorable survival trend for patients who received Nexavar.  In April 2005, the trial was unblinded and patients who were receiving placebo could “cross over” to treatment with Nexavar based on the clinical and statistical significance of a definitive analysis of progression free survival.  The final analysis of OS is planned when 540 events are observed.

“Consistent with the original interim analysis, patients receiving Nexavar lived longer than patients receiving placebo, despite almost 50% of placebo patients crossing over to Nexavar,” said Dr. Eisen.  “These data are encouraging and should be considered preliminary pending the final analysis,” said Dr. Eisen.

Quality of Life (QOL) Data (Abstract #4534)
An evaluation of health-related quality of life and symptoms of the Phase III patient population was also presented today.  In the study, Nexavar demonstrated a clinical benefit (as evidenced by Progression Free Survival) without adversely impacting overall quality of life, and had a positive impact on individual symptoms, such as cough, fevers, “shortness of breath”, “worry that condition will worsen” and “ability to enjoy life.”

“Quality of life is such an important issue for kidney cancer patients as many of them do not have evident disease symptoms,” said Bill Bro, president of the Kidney Cancer Association.  “Today, patients are focused on treating their disease without compromising the way they live.  They want to be able to manage their cancer in a way that doesn’t limit their daily activities.”

Phase III Summary
More than 900 patients with advanced RCC, who had previously failed one prior systemic therapy, were randomized one-to-one to receive either 400 mg Nexavar or placebo twice a day.  The primary endpoint of the study is overall survival, with progression-free survival (PFS), overall response rate, quality of life, and safety also being assessed.  PFS measures the length of time that a patient lives without evident tumor growth or death.

In April 2005, the companies unblinded the trial and announced that patients enrolled in the Phase III kidney cancer trial who were receiving placebo could “cross over” to drug treatment based on the clinical and statistical significance of the definitive analysis of PFS data.  Overall
survival results presented at ASCO 2006 were based on an analysis of 367 survival events (patient deaths) that had occurred by November 30, 2005.

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-B, KIT, and FLT-3.

Nexavar has been studied in more than 20 tumor types and in more than 8,000 clinical trial patients.  It has demonstrated combinability with multiple anticancer agents, and 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.

About Kidney Cancer
Renal cell carcinoma is the most common form of kidney cancer.  Nearly 208,000 people worldwide are diagnosed (about 37,000 Americans) with renal cell carcinoma each year and more than 102,000 of them die (about 12,000 Americans) from the disease annually.  For more information on renal cell carcinoma, visit the Kidney Cancer Association (KCA) web site at:

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 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.

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

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