Bayer and Onyx Announce Pivotal Nexavar® Kidney Cancer Study Published in New England Journal of Medicine

WEST HAVEN, Conn. and EMERYVILLE, Calif. — Jan. 10, 2007

Bayer Pharmaceuticals Corporation (NYSE: BAY) and Onyx Pharmaceuticals,
Inc. (Nasdaq: ONXX) today announced that the New England Journal of Medicine
has published their pivotal Phase III trial demonstrating that Nexavar®
(sorafenib) tablets doubled median progression-free survival (PFS) in patients
with advanced renal cell carcinoma (RCC), or kidney cancer. The data, as
assessed by independent radiologic review, are from the Treatment Approaches
in Renal Cancer Global Evaluation Trial (TARGET) — the largest randomized
controlled trial ever conducted in advanced RCC.

“Historically, patients with kidney cancer have had limited treatment
options and there has been a particularly critical need for new therapies to
help patients with advanced disease,” said co-principal investigator Ronald
Bukowski, M.D., Director of the Experimental Therapeutics Program of The
Cleveland Clinic Taussig Cancer Center in Cleveland, OH. “This landmark study
demonstrated the efficacy, tolerability and clinical benefit of Nexavar, which
has rapidly become a valuable weapon against this devastating disease.”
Based on these data, Nexavar was granted U.S. Food and Drug Administration
(FDA) approval for the treatment of patients with advanced RCC, or kidney
cancer, on December 20, 2005. Since then, Nexavar has been approved in nearly
50 countries.

“Nexavar was the first new drug approved for patients with advanced kidney
cancer in over a decade,” said Bill Bro, President and Chief Executive Officer
of the Kidney Cancer Association (KCA). “With the advent of targeted
therapies such as Nexavar, there has been remarkable change — patients are
experiencing improved outcomes without the toxic effects traditionally
associated with chemotherapy.”

Phase III Summary
More than 900 patients with advanced RCC were randomized
one-to-one to receive either 400 mg Nexavar or placebo orally twice a day in
this randomized, multi-national, placebo-controlled Phase III study. The
endpoints of the study are overall survival (OS), PFS, overall response rate
and safety. PFS measures the length of time that a patient lives without
evident tumor growth or death.

PFS doubled to a median of 5.5 months in patients receiving Nexavar
compared to 2.8 months for patients receiving placebo (p < 0.001). This
represented a 56% reduction in the risk of progression (hazard ratio 0.44; 95%
CI, 0.35 to 0.55) for patients on Nexavar versus placebo. All patient
subgroups examined benefited regardless of performance status or risk group,
including patients who had not received conventional treatment with biologics,
such as interleukin-2 or interferon-alpha.

In May 2005, due to the clinical and statistical significance of the PFS
data, the companies unblinded the trial and announced that patients who were
receiving placebo were allowed to “cross over” to drug treatment. The first OS
analysis conducted immediately before cross-over found a 39% improvement in OS
for Nexavar patients (hazard ratio 0.72, p=0.018). A further OS analysis
performed six months following cross over was based on 367 survival events
(patient deaths) that had occurred by November 30, 2005. Results showed a
continued trend toward improved survival, with a 23% reduction in the risk of
death (19.3 months for Nexavar patients versus 15.9 months for placebo
patients; hazard ratio 0.77, p=0.02), despite the fact that nearly half of
placebo patients had “crossed over” to Nexavar. Patients continue to be
followed and a final survival analysis will be available in the first half of
2007. The Phase III data published in NEJM have previously been communicated
at international scientific congresses.

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-1, VEGFR-2, VEGFR-3,

Nexavar is currently approved in nearly 50 countries, including the United
States and in the European Union, for the treatment of patients with advanced
kidney cancer. In addition, Nexavar is being evaluated by the companies,
international study groups, government agencies or individual investigators as
a single agent or combination treatment in a wide range of cancers, including
adjuvant RCC, advanced liver cancer, metastatic melanoma, non-small cell lung
cancer and breast cancer.

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 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:

About Bayer Pharmaceuticals Corporation
Bayer Pharmaceuticals Corporation ( is part of
the worldwide operations of Bayer HealthCare AG, a subsidiary of Bayer AG.
Bayer HealthCare is one of the world’s leading, innovative companies in the
healthcare and medical products industry and is based in Leverkusen, Germany.
Bayer HealthCare generated sales amounting to some 9.4 billion euros and
employed 33,800 people worldwide in 2005.

The company combines the global activities of the Animal Health, Consumer
Care, Diabetes Care, and Pharmaceuticals divisions. The new Pharmaceuticals
division was established on January 1, 2006, and comprises the former
Biological Products and Pharmaceutical divisions. Bayer HealthCare
Pharmaceuticals now has three business units: Hematology/Cardiology, Oncology
and Primary Care.

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

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

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® is a registered trademark of Bayer AG, Germany.

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