2. Enbrel
The companies: Amgen, Pfizer, Takeda
Worldwide sales: $8.776 billion

Enbrel was the first of its kind, a TNF (tumor necrosis factor) inhibitor to treat autoimmune diseases, and its distinction allowed it to become one of the best-selling drugs in the world. It was first approved by the FDA more than 15 years ago in 1998 for treating moderate to severe rheumatoid arthritis, but it has racked up four more approvals in the U.S. since then and the revenues to go with it. Amgen bought its developer, Immunex, in 2002 for about $16 billion, a deal that seemed incredible to some at the time, but that in retrospect was a bargain.

Its age and its success have made it a marked drug with biosimilar developers placing it at the top of their lists. Merck ($MRK) was among those who intended to knock it off when it went off patent in October 2012. Amgen ($AMGN) outmaneuvered them. In 2011, it won a new patent that could shield the drug for another 17 years, at least in the U.S. That put Merck off the hunt but didn't discourage Cipla, which announced the launch of an Enbrel biosimilar in India, a country with a laissez-faire attitude about patents. It is selling its version there at a 30% discount to Enbrel. As the discount indicates, the price difference between the original and the copies will not be anything like that found in small molecule generics, which will help those companies like Amgen with valuable biologics.

Even 15 years in, Enbrel continues to enjoy sales gains, growing 14% for Amgen in 2012 and another 7% last year. Most of Enbrel's revenues go to Amgen, but partner Pfizer ($PFE) sold it outside the U.S. In Japan, Pfizer partners with Takeda. Pfizer grossed about $1 billion last year, but its partnership with Amgen dissolved in October.

For more:
Pfizer, Amgen prepare to dissolve Enbrel partnership
Cipla steamrolls into Enbrel market with biosimilar of Amgen drug
Amgen's new Enbrel patent could delay biosims for 17 years
Enbrel beats rivals in rheumatologist survey

-- Eric Palmer (email | Twitter)


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