Sandoz sued by Sanofi to Protect Ambien Patent

Sanofi-Aventis filed a law suit on Friday against Sandoz, a subsidiary of Novartis AG, to keep Sandoz away from marketing its generic version of insomnia drug Ambien CR.

Sandoz recently filed an ANDA with the USFDA to market a generic extended-release pill containing zolpidem tartrate, the active ingredient in Ambien, before Sanofi's patent on the drug, U.S. Patent Number 6,514,531, expires, Sanofi says in a complaint filed in the U.S. District Court for the District of New Jersey.

The '531 patent, issued to Sanofi in 2003, describes a “controlled-release dosage forms of zolpidem or salts thereof adapted to release zolpidem over a predetermined time period.”

Sandoz claimed in its ANDA that the '531 patent is invalid, according to Sanofi's complaint.

“By filing the ANDA ... for the purpose of obtaining approval to engage in the commercial manufacture, use or sale of its proposed zolpidem tartrate extended release tablets before the expiration of the '531 patent, Sandoz has committed an act of infringement,” Sanofi said.

“Further, the commercial manufacture, use, offer for sale, sale and/or importation of tablets made under that ANDA will also infringe one or more claims of the '531 patent,” it said.

Sanofi has asked the court to enjoin Sandoz from selling a generic version of
Ambien until the '531 patent expires and to award monetary damages for any other
acts of infringement it might find.

Sanofi has also moved to protect the market for Ambien, which currently has no competitors, from generic competition by other companies.

Last June, the company sued Mutual Pharmaceutical Company Inc., United Research Laboratories Inc. and their parent company Pharmaceutical Holdings Corp., which had also filed an ANDA to make generic versions of Ambien. Those suits are still pending in the District of New Jersey.

In addition, Sanofi filed suit in February 2007 against Dutch pharmaceutical company Synthon Holding BV over an ANDA Synthon submitted in a bid for FDA approval to market generic Ambien in the U.S.

As in the suits against Sandoz and Mutual, Sanofi asserted the '531 patent in
its suit against Synthon.

Ambien, which was approved for sale in the United States in the early 1990s, is
one of Sanofi's biggest sellers, generating $1.9 billion in sales during the
first nine months of 2006.