Pfizer is facing at least three class action lawsuits alleging that the company went to extraordinary, fraudulent lengths to maintain exclusivity over its multibillion dollar arthritis pain drug Celebrex and keep generic competitors off the market.

The suits, filed last week by a pair of union health funds and a wholesaler, allege that Pfizer deceived the U.S. Patent and Trademark Office in filing new and updated patents on Celebrex (celecoxib) and then pursued sham litigation against ANDA filers to prevent competition at least until the end of this year.

Those actions kept Celebrex at supracompetitive prices that cost thousands or perhaps millions of patients in the U.S. untold sums of money, according to the complaint by the American Federation of State, County and Municipal Employees’ Health and Welfare Fund. Also launching lawsuits are American Sales Company and the United Food and Commercial Workers Unions’ Midwest Health Benefits Fund.

The suits contend that Pfizer filed patent addendums that were merely restatements of existing art to deter generics makers and force them to agree to delays of products that satisfied Pfizer. As a result, last month Mylan settled a lawsuit with Pfizer over a Celebrex generic, with plans to launch by December. Teva won approval, and controversial exclusivity, a few days earlier.

Pfizer flatly rejected the accusations, saying it is “confident that the procurement and enforcement of … Celebrex patents were at all times proper and lawful.”

Celebrex earned Pfizer more than $2 billion last year. — Bryan Koenig

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.