Bayer and Onyx Initiate Phase 3 Trial of Nexavar in Non-Small Cell Lung Cancer

WAYNE, N.J. and EMERYVILLE, Calif. — Bayer HealthCare Pharmaceuticals, Inc. and Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) today announced that the companies have begun enrolling patients in an international Phase 3 trial to evaluate Nexavar(R) (sorafenib) tablets in patients with non-squamous non-small cell lung cancer (NSCLC) who have failed two or three previous treatments.

“Nexavar has proven efficacy in liver cancer and kidney cancer and we are committed to researching Nexavar in a variety of other solid tumors,” said Dimitris Voliotis, MD, vice president, Nexavar Clinical Development, Bayer HealthCare Pharmaceuticals. “Based on the results of a signal generating Phase 2 study, Bayer and Onyx initiated this Phase 3 trial to evaluate Nexavar in non-small cell lung cancer.”

Phase 3 Trial Design

The MISSION (Monotherapy admInistration of Sorafenib in patientS wIth nOn-small cell luNg cancer) trial, is an international multicenter study that will enroll approximately 850 patients with advanced relapsed or refractory non-squamous NSCLC who have failed two or three previous treatments. Patients will be randomized to receive either Nexavar as single agent or placebo. In both treatment arms, best supportive care will be provided. The primary endpoint of this trial is overall survival, and secondary endpoints include progression-free survival and overall response rate. The safety and tolerability of the two treatment groups will also be compared.

The study will be conducted at more than 120 sites in North America, South America, Europe, Africa and the Asia-Pacific region, including Japan. For information about this study, please visit www.clinicaltrials.gov.

“As the leading cause of cancer deaths worldwide, lung cancer is a complex disease that requires new therapeutic options for patients,” said Laura Brege, executive vice president and chief operating officer at Onyx Pharmaceuticals. “We are committed to studying Nexavar to understand how it may play a role in the treatment paradigm of this difficult-to-treat disease.”

About Non-Small Cell Lung Cancer (NSCLC)

NSCLC accounts for 85-90 percent of diagnosed lung cancers(1) and is a disease in which malignant (cancer) cells form in the tissues of the lung. It is characterized by several types of lung cancers, each of which grow and spread in different ways, including: squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.(1)

Every year 1.4 million people worldwide will be diagnosed with lung cancer and 1.2 million will die from the disease.(2) Nearly 60 percent of Americans diagnosed with lung cancer die within one year of their diagnosis and 75 percent die within 2 years. These survival rates have not improved in the past 10 years.(3)

Nexavar’s Differentiated Mechanism

Nexavar, an oral anti-cancer therapy, is currently approved in more than 70 countries for liver cancer and in more than 80 countries for the treatment of patients with advanced kidney cancer. 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.

Nexavar is also being evaluated by the companies, international study groups, government agencies and individual investigators as a single agent or combination treatment in a wide range of cancers, including, breast cancer, colorectal cancer, lung cancer, ovarian cancer, and as an adjuvant therapy for kidney cancer and liver cancer.

Important Safety Considerations For Patients Taking Nexavar

Based on the currently approved U.S. package insert for the treatment of patients with unresectable hepatocellular carcinoma, 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. Bleeding with a fatal outcome from any site was reported in 2.4% for Nexavar and 4% in placebo. The incidence of treatment-emergent cardiac ischemia/infarction was 2.7% for Nexavar vs. 1.3% for placebo. Most common adverse events reported with Nexavar in patients with unresectable HCC were diarrhea, fatigue, abdominal pain, weight loss, anorexia, nausea and hand-foot skin reaction. Grade 3/4 adverse events were 45% for Nexavar vs. 32% 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 information about Nexavar including U.S. Nexavar prescribing information, visit www.nexavar.com or call 1.866.NEXAVAR (1.866.639.2827).

About Bayer HealthCare Pharmaceuticals Inc.

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 U.S., 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 Onyx Pharmaceuticals, Inc.

Onyx Pharmaceuticals, Inc. is a biopharmaceutical company committed to improving the lives of people with cancer. The company, in collaboration with Bayer HealthCare Pharmaceuticals, Inc., is developing and marketing Nexavar(R) (sorafenib) tablets, a small molecule drug. For more information about Onyx, visit the company’s website at www.onyx-pharm.com.

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 our annual and interim reports filed with the Frankfurt Stock Exchange. The company 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, safety, 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, 2008, 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(R) (sorafenib) tablets is a registered trademark of Bayer HealthCare Pharmaceuticals, Inc.

(1) Non-Small Cell Lung Cancer Detailed Guide from American Cancer Society. Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_4_7x_Lung_Cancer_-_Non-Small_Cell_Detailed_Guide.asp. Accessed April 9, 2009.

(2) 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 9, 2009.

(3) National Cancer Institute SEER data. Available at: http://seer.cancer.gov/statistics/. Accessed April 9, 2009