In the largest purchase of a cancer-focused biopharmaceutical company since Roche bought Genentech in 2009, Amgen, of Thousand Oaks, CA, will buy Onyx Pharmaceuticals, of South San Francisco, CA, for $10.4 billion.

Amgen, of Thousand Oaks, CA, will buy Onyx Pharmaceuticals, of South San Francisco, CA, for $10.4 billion. The acquisition will be the largest purchase of a cancer-focused biopharmaceutical company since Roche bought Genentech in 2009 for $46.8 billion.

As Amgen looked to bolster its oncology portfolio, Onyx's star attraction was the proteasome inhibitor Kyprolis (carfilzomib), approved by the U.S. Food and Drug Administration (FDA) in 2012 for treating patients with multiple myeloma who have received at least two prior therapies. Five phase III trials are under way studying Kyprolis for patients with the disease. Amgen expects rapid revenue growth for the injected drug, whose U.S. patents extend until at least 2025. Eun Yang, PhD, an analyst with Jefferies, predicts that Kyprolis will post global sales of $1.2 billion next year.

Most of Onyx's current earnings are drawn from Nexavar (sorafenib), which inhibits multiple kinases thought to be involved in both cell proliferation and angiogenesis. Onyx is partnered with Bayer HealthCare Pharmaceuticals on the drug, which has been approved by the FDA for unresectable hepatocellular carcinoma and advanced renal cell carcinoma. Onyx also partners with Bayer on Stivarga (regorafenib), another multikinase inhibitor, which is approved for certain patients with metastatic colorectal cancer or advanced gastrointestinal stromal tumor.

Additionally, Onyx receives royalties on Pfizer's palbociclib (PD-0332991), an inhibitor of cyclin-dependent kinases 4 and 6 that has received Breakthrough Therapy designation by the FDA for the potential treatment of patients with ER+, HER2- breast cancer. Onyx also has reported positive early trial results for its oral proteasome inhibitor oprozomib.

Onyx was formed in 1992 to develop virus-based therapeutics for cancer. The firm went public in 1996, acquired Kyprolis in 2009 by buying Proteolix, and raised about $350 million in its most recent stock offering, earlier this year. It posted $153 million in revenue with a loss of $53.2 million for the quarter ended June 30, 2013.

Amgen reported $17.3 billion in sales and $4.3 billion in net income in 2012. That year the company bought the human genetics pioneer deCODE Genetics, of Reykjavik, Iceland, and Micromet, of Rockville, MD, whose blinatumomab (AMG 103) has demonstrated promising results in a phase II trial in B-precursor acute lymphoblastic leukemia.

©2013 American Association for Cancer Research.
2013