Amgen is the biggest biotech drug company in the world. Its products include Prolia for osteoporosis, Enbrel for rheumatoid arthritis and skin disorders, and Neulasta and Neupogen for fighting infection in cancer patients. The Thousand Oaks, Calif., company reported $17.27 billion in revenue in 2012. It said Onyx will start adding to its adjusted net income in 2015.
Onyx Pharmaceuticals Inc. makes two cancer drugs through a partnership with Bayer AG. Sales of Nexavar, a pill that is approved to treat liver and kidney cancer, totaled $861 million in 2012. Onyx received $288 million in revenue from those sales. Stivarga was approved in September as a treatment for colorectal cancer, and won additional approval in February for use against tumors of the intestinal tract that did not respond to other treatments.
In July the FDA approved Onyx's Kyprolis as a treatment for multiple myeloma, a type of blood cancer.
Multiple myeloma causes tumors to grow in the bone marrow, preventing the production of normal blood cells. The FDA approved Kyprolis for patients who have already been treated with at least two other multiple myeloma drugs, and Onyx is conducting other trials to win broader marketing approval. Onyx and Bayer are also testing Nexavar as a treatment for breast cancer.
The new offer comes at a 44 percent premium to Onyx's closing price on June 28, before reports of Amgen's initial bid. In the days after Amgen's first offer was made public, shares of the South San Francisco company climbed as high as $136.87. The stock closed at $116.96 Friday.
The Onyx drugs would add to Amgen's pipeline of new drugs. In the first half of 2014 Amgen expects to announce late-stage testing data for three experimental drugs. The products are being studied as treatments for skin cancer, recurrent ovarian cancer and high LDL, or bad cholesterol, that doesn't respond to pills such as Lipitor.
Onyx and Pfizer Inc. are also studying a drug called palbociclib as a treatment for breast cancer, and oprozomib, a potential multiple myeloma drug that is in early clinical testing.
Several other major pharmaceutical acquisitions have been announced in the last few months. In July, generic drug maker Perrigo Co. agreed to buy Ireland's Elan Corp. PLC for $8.6 billion. That deal will allow Perrigo to move to Ireland and cut its tax obligations while adding new royalties. In May generic drug company Actavis Inc. agreed to buy Warner Chilcott PLC for $8.5 billion in stock, creating the third-biggest specialty pharmaceutical company in the U.S. market.
Also in May, Valeant Pharmaceuticals International Inc. agreed to pay $8.7 billion to buy Bausch + Lomb in a massive expansion of Valeant's ophthalmology business. In April scientific instrument maker Thermo Fisher Scientific Inc. agreed to buy life science and medical research instrument maker Life Technologies Corp. for $13.6 billion.