Onyx Pharmaceuticals

Onyx Pharmaceuticals Inc.

Company type	Public (former)
Industry	Biopharmaceuticals, Oncology therapeutics
Founded	1992 (1992)
Founder	Kevin J. Kinsella, Frank McCormick
Defunct	August 25, 2013 (2013-08-25)
Fate	Acquired by Amgen
Successor	Amgen
Headquarters	South San Francisco , United States
Area served	Worldwide
Key people	N. Anthony (Tony) Coles (CEO), Kevin J. Kinsella (Chairman), Frank McCormick (former Chief Scientific Officer)
Products	Sorafenib (Nexavar), Carfilzomib (Kyprolis), Regorafenib (Stivarga)
Owner	Amgen (since 2013)
Parent	Amgen

Onyx Pharmaceuticals Inc., based in South San Francisco, California, was a biopharmaceutical enterprise concentrating on oncology therapeutics. Established in 1992 by entrepreneurs Kevin J. Kinsella and Frank McCormick Ph.D., FRS, McCormick held the position of chief scientific officer until 1998, while Kinsella served as chairman. In 2009, Onyx expanded its product lineup by acquiring the biotech company Proteolix, Inc. for $276 million plus additional milestone payments. By early 2012, industry analyses identified Onyx as the leading biotechnology acquisition candidate, underscoring its robust drug pipeline and market presence. CEO N. Anthony (Tony) Coles highlighted the firm’s dedication to pioneering treatments and maintaining autonomy. Nevertheless, in August 2013, Amgen completed a $10.4 billion acquisition of Onyx, marking a pivotal moment in the company’s history.

The company’s initial capital was provided by biotechnology pioneer Chiron Corporation, which obtained a 43% ownership stake, alongside venture capital investors such as Avalon Ventures, Institutional Venture Partners, J. H. Whitney & Company, and Kleiner Perkins Caufield & Byers. McCormick transitioned from leading cancer research at Chiron to spearhead Onyx’s research initiatives as vice president of research. Samuel D. Colella, a partner at Institutional Venture Partners, acted as interim president during the company’s founding phase.

This overview emphasizes Onyx’s strategic management decisions, important acquisitions, and business expansion within the competitive biotech sector before its integration into Amgen's worldwide operations.

Products and development

Sorafenib, developed and co-marketed with Bayer under the brand name Nexavar, received FDA approval in the United States for treating advanced renal cell carcinoma in 2005 and for unresectable hepatocellular carcinoma in 2007. Additionally, it has undergone clinical evaluation for thyroid and breast cancers.

Carfilzomib (Kyprolis) gained FDA approval in June 2012 for patients with multiple myeloma who had previously received at least two treatment regimens, including bortezomib and immunomodulatory agents, with disease progression evident. It is also being investigated for other multiple myeloma stages. Frequently reported side effects include fatigue, anemia, nausea, thrombocytopenia, shortness of breath, diarrhea, and fever.

Regorafenib (Stivarga), developed by Bayer, holds FDA approval for treating metastatic colorectal cancer following prior therapies and for advanced gastrointestinal stromal tumor (GIST) after treatment with imatinib and sunitinib. Common adverse effects are fatigue, hand-foot skin reaction, diarrhea, decreased appetite, hypertension, mucositis, voice changes, infections, pain, weight loss, rash, fever, and nausea. Bayer and Onyx collaborate on Stivarga’s promotion within the US market; Onyx receives a 20% royalty on future global net sales.

In June 2013, Amgen Inc proposed an acquisition offer of $120 per share for Onyx Pharmaceuticals, resulting in approximately a 30% increase in Onyx’s stock price. Although Onyx declined this unsolicited proposal initially, it authorized its financial advisors to explore alternative buyers. The transaction was completed on August 25, 2013.

In July 2014, Onyx disclosed that a phase III clinical trial testing a combination of Sorafenib and Capecitabine failed to demonstrate improved progression-free survival in patients with advanced breast cancer.