Onyx Pharmaceuticals Announces Data Presentations Highlighting Carfilzomib and Oprozomib at 54th American Society of Hematology Annual Meeting

SOUTH SAN FRANCISCO, CA--(Marketwire - Nov 6, 2012) - Onyx Pharmaceuticals, Inc. (NASDAQ: ONXX) today announced the presentation of several studies evaluating carfilzomib, a selective, irreversible proteasome inhibitor, and oprozomib, an investigational oral proteasome inhibitor, previously known as ONX0912, at the 54^th American Society of Hematology (ASH) Annual Meeting and Exposition on December 8-11, 2012 at the Georgia World Congress Center in Atlanta, GA.

"The results being presented at ASH add to the depth and breadth of clinical experience for carfilzomib in a range of multiple myeloma disease settings, and begin to build our clinical understanding of oprozomib," said Barbara Klencke, M.D., Senior Vice President of Clinical Development at Onyx Pharmaceuticals. "We are encouraged by the data to be presented and the ongoing investigator and company-sponsored studies that will expand our knowledge of the appropriate use of carfilzomib. We remain committed to further studying our proteasome inhibitor therapies in multiple myeloma, other hematologic malignancies and, potentially, solid tumors."

Carfilzomib data highlights include

Phase II Study of Infusional Carfilzomib in Patients with Relapsed or Refractory Multiple Myeloma

• Dr. Nikoletta Lendvai, Memorial Sloan-Kettering Cancer Center

• Tuesday, December 11, 8:30 - 8:45 a.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation: Clinical issues in myeloma and amyloidosis patients: novel agent and novel agent-based combinations

• Abstract # 947

Results from the Phase II Dose Expansion of Cyclophosphamide, Carfilzomib, Thalidomide and Dexamethasone (CYCLONE) in Patients with Newly Diagnosed Multiple Myeloma

• Dr. Joseph Mikhael, Mayo Clinic

• Monday, December 10, 10:30 - 10:45 a.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation II

• Abstract # 445

Carfilzomib Combined with Thalidomide and Dexamethasone (CTD) Is an Highly Effective Induction and Consolidation Treatment in Newly Diagnosed Patients with Multiple Myeloma (MM) Who Are Transplant Candidate

• Dr. Pieter Sonneveld, Erasmus Medical Center, Rotterdam, Netherlands

• Monday, December 10, 7:30 - 7:45 a.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation: Treatment options for newly diagnosed myeloma patients

• Abstract # 333

Carfilzomib, Cyclophosphamide and Dexamethasone (CCd) for Newly Diagnosed Multiple Myeloma (MM) Patients

• Dr. Antonio Palumbo, University of Torino, Italy

• Monday, December 10, 5:15 - 5:30 p.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation III

• Abstract # 730

Phase II Clinical and Correlative Study of Carfilzomib, Lenalidomide, and Dexamethasone (CRd) in Newly Diagnosed Multiple Myeloma (MM) Patients

• Dr. Ola Landgren, National Cancer Institute (NCI)

• Monday, December 10, 5:45 - 6:00 p.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation III

• Abstract # 732

A Multi-Center Phase I/II Trial of Carfilzomib and Pomalidomide with Dexamethasone (Car-Pom-d) in Patients with Relapsed/Refractory Multiple Myeloma

• Dr. Jatin Shah, The University of Texas MD Anderson Cancer Center

• Sunday, December 9, 12:15 - 12:30 p.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation: Phase I-II trials in Relapsed and Relapsed-Refractory myeloma patients

• Abstract # 74

Cardiac Event Rates in Patients with Newly Diagnosed and Relapsed Multiple Myeloma in US Clinical Practice

• Dr. Kristin Kistler, United BioSource Corporation

• Sunday, December 9, 6:00 - 8:00 p.m., Hall B1-B2

• Poster Session: Myeloma - Biology and Pathophysiology, excluding Therapy: Poster II

• Abstract #2916

A Phase Ib Study of 30-minute Infusion Carfilzomib 20/45 and 20/56 mg/m2 plus 40 mg Weekly Dexamethasone in Patients with Relapsed and/or Refractory (R/R) Multiple Myeloma

• Dr. Ashraf Badros, University of Maryland Medical Center

• Monday, December 10, 6:00 - 8:00 p.m., Hall B1-B2

• Poster Session: Myeloma - Therapy, excluding Transplantation: Poster III

• Abstract # 4036

Cardiac and Pulmonary Safety Profile of Single-agent Carfilzomib from Four Phase II Studies in Patients with Relapsed and/or Refractory Multiple Myeloma

• Dr. Sagar Lonial, Winship Cancer Institute of Emory University

• Monday, December 10, 6:00 - 8:00 p.m., Hall B1-B2

• Poster Session: Myeloma: Therapy, excluding Transplantation: Poster III

• Abstract # 4037

A Phase II Study of Prolonged Carfilzomib Therapy in Patients with Multiple Myeloma Previously Enrolled in Carfilzomib Phase 1 and 2 Clinical Trials

• Dr. David Siegel, Hackensack University Medical Center

• Sunday, December 9, 6:00 - 8:00 p.m., Hall B1-B2

• Poster Session: Myeloma: Therapy, excluding Transplantation: Poster II

• Abstract # 2962

Oprozomib data highlights include

A Phase Ib Dose-escalation Study of Split-dose Oprozomib (ONX0912) in Patients with Hematologic Malignancies

• Dr. Michael Savona, Tennessee Oncology

• Sunday, December 9, 5:30 - 5:45 p.m., Thomas Murphy Ballroom 2-3

• Oral Session: Myeloma - Therapy, excluding Transplantation I

• Abstract # 203

Important Indication and Safety Information for carfilzomib
On July 20, 2012, the U.S. Food and Drug Administration (FDA) granted accelerated approval of Kyprolis™ (carfilzomib) for Injection for the treatment of patients with multiple myeloma who have received at least two prior therapies including bortezomib and an immunomodulatory agent (IMiD), and have demonstrated disease progression on or within 60 days of completion of the last therapy. Approval was based on response rate. Clinical benefit, such as improvement in survival or symptoms, has not been verified.

Safety data have been evaluated in 526 patients with relapsed and/or refractory multiple myeloma who received single-agent Kyprolis. There were 37 deaths in the phase 2 studies, or 7% of patients. The most common causes of death, other than disease progression, were cardiac (5 patients), end-organ failure (4 patients), and infection (4 patients). Important warnings and precautions include cardiac arrest, congestive heart failure, myocardial ischemia; pulmonary hypertension, pulmonary complications, infusion reactions, tumor lysis syndrome, thrombocytopenia, hepatic toxicity and embryo-fetal toxicity.

Death due to cardiac arrest has occurred within a day of Kyprolis administration. Patients with New York Heart Association Class III and IV heart failure, myocardial infarction in the preceding 6 months, and conduction abnormalities uncontrolled by medications were not eligible for the clinical trials. These patients may be at greater risk for cardiac complications.

Pulmonary arterial hypertension (PAH) was reported in 2% of patients treated with Kyprolis and was Grade 3 or greater in less than 1% of patients. Dyspnea was reported in 35% of patients enrolled in clinical trials. Grade 3 dyspnea occurred in 5%; no Grade 4 events, and 1 death (Grade 5) was reported.

Infusion reactions, characterized by a spectrum of systemic symptoms including fever, chills, arthralgia, myalgia, facial flushing, facial edema, vomiting, weakness, shortness of breath, hypotension, syncope, chest tightness, or angina can occur immediately following or up to 24 hours after administration of Kyprolis. Administration of dexamethasone prior to Kyprolis reduces the incidence and severity of reactions. Tumor lysis syndrome (TLS) occurred following Kyprolis administration in < 1% of patients. Patients with multiple myeloma and a high tumor burden should be considered to be at greater risk for TLS.

Thrombocytopenia following Kyprolis administration resulted in a dose reduction in 1% of patients and discontinuation of treatment with Kyprolis in < 1% of patients.

Cases of hepatic failure, including fatal cases, have been reported (< 1%). Kyprolis can cause elevations of serum transaminases and bilirubin.

There are no adequate and well-controlled studies in pregnant women using Kyprolis. Females of reproductive potential should be advised to avoid becoming pregnant while being treated with Kyprolis.

The most common serious adverse reactions were pneumonia, acute renal failure, pyrexia, and congestive heart failure. The most common adverse reactions (incidence of 30% or greater) observed in clinical trials of patients with multiple myeloma were fatigue, anemia, nausea, thrombocytopenia, dyspnea, diarrhea, and pyrexia. Serious adverse reactions were reported in 45% of patients.

Full prescribing information is available at http://www.kyprolis.com.

About Multiple Myeloma
Multiple myeloma is the second most common hematologic cancer and results from an abnormality of plasma cells, usually in the bone marrow. In the United States, more than 50,000 people are living with multiple myeloma and approximately 20,000 new cases are diagnosed annually.¹ Worldwide, more than 220,000 people are living with multiple myeloma and approximately 100,000 new cases are diagnosed annually.²

About Onyx Pharmaceuticals, Inc.
Based in South San Francisco, California, Onyx Pharmaceuticals, Inc. is a global biopharmaceutical company engaged in the development and commercialization of innovative therapies for improving the lives of people with cancer. The company is focused on developing novel medicines that target key molecular pathways. For more information about Onyx, visit the company's website at www.onyx.com.

Forward-Looking Statements
This news release contains "forward-looking statements" of Onyx within the meaning of the federal securities laws. These forward-looking statements include without limitation, statements regarding the progress and results of the clinical development, safety, regulatory processes, commercialization efforts or commercial potential of Kyprolis (carfilzomib) or oprozomib. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including risks related to the development and commercialization of pharmaceutical products. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Reference should be made to Onyx's Annual Report on Form 10-K for the year ended December 31, 2011, 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.

¹ American Cancer Society, Cancer Facts & Figures 2012

² National Analysts & Kantar Health Market Research