Drug: Aciphex
Generic: Rabeprazole
Company: Eisai, Johnson & Johnson ($JNJ)
Patent expiration date: May 8, 2013
Estimated Global Sales 2012: $1.93 billion

The scoop: Eisai's heartburn medication Aciphex generated close to $1.1 billion in sales for the Japanese company last year and more  than  $860 million for partner Johnson & Johnson. As one of only about half a dozen drugs Eisai sells in the U.S., losing its patent is a big hit. In 2007 it held off generic competition from Dr. Reddy's and Teva ($TEVA). It also made a run at producing an extended release version but dropped that effort in 2011 after receiving a Complete Response Letter from the FDA. Sales have already been dropping off, at least for Johnson & Johnson, which reported a 10% decline for the first 9 months of this fiscal year, to $649 million. Eisai in October snagged FDA approval for blockbuster hopeful Fycompa, its new epilepsy drug, which should take away some of the pain of losing the Aciphex patent next year.

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Eisai snags FDA nod for blockbuster hopeful Fycompa
For Eisai in China, the sales rep's the thing

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