Mylan looks to become first to market generic ulcerative proctitis drug

PITTSBURGH — Mylan is challenging a patent on a drug used to treat ulcerative proctitis, the generic drug maker said Thursday.

Mylan said it had filed a regulatory approval application with the Food and Drug Administration for melamine rectal suppositories in the 1,000-mg strength. The drug is a generic version of Canasa, which had sales of about $153 million during the 12-month period that ended in March, according to IMS Health.

Mylan's application contained a Paragraph IV certification, a legal assertion that patents covering the drug are invalid, unenforceable or not in danger of infringement. In response to the filing, Aptalis, the company that makes Canasa, filed a patent-infringement suit against Mylan in the U.S. District Court for the District of New Jersey.

Under regulations governing generic drugs, Mylan expects to be eligible for 180 days of market exclusivity after the FDA approves the drug.