Last week, Allergan (NYSE:AGN) said that it filed lawsuits against Imprimis Pharmaceuticals (NSDQ:IMMY), Prescriber’s Choice and Sincerus Florida, claiming that the companies manufacture, sell and promote unapproved new drugs.

The pharmaceutical giant filed suit in the U.S. District Court for the Central District of California. Today, Imprimis fired back at Allergan, denying the allegations and saying that it plans to ‘aggressively defend itself against Allergan’s frivolous lawsuit.’

“Biopharmaceutical companies like Allergan have a duty to put the safety of their patients first. This commitment is the cornerstone of our manufacturing, marketing and advertising of our FDA-approved products,” Allergan said in prepared remarks. “Today, we have brought suit against companies that we believe stand in stark contrast to that commitment. Imprimis Pharmaceuticals, Inc., Prescriber’s Choice, Inc., and Sincerus Florida, LLC do not follow the established compounding regulations, engage in false and misleading advertising, and ultimately, put patients and physicians at risk by selling unapproved new drugs.”

“Allergan’s illegal, abusive, and anticompetitive actions aimed at maintaining its obscenely high drug prices reveal its true socially unconscious values,” Imprimis CEO Mark Baum countered in a press release. “Despite Allergan’s misuse of its massive resources against a lawful competitor, Imprimis is winning support where it counts the most: among the nation’s leading ophthalmologists, and the patients that together we serve.”

Imprimis characterized Allergan as a ‘well-known professional litigant’, pointing towards issues like ongoing investigations into the company’s marketing and drug pricing practices.

Imprimis also described Allergan’s latest move to sell patents for its Restasis drug to a Native American tribe as an attempt to ‘thwart the US legal system and avoid lower-cost generic competition’.

Last week, Allergan said it transferred the patent rights for its opthalmic formulation of cyclosporine to the St. Regis Mohawk Tribe. Patented intellectual property owned by the tribe is protected from inter partes review challenges thanks to the tribe’s sovereign immunity – and it just so happens that last December, the U.S. Patent Office granted an inter partes review of Allergan’s Restasis patents.

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