A former drug distributor filed a class action lawsuit against Novartis and Par Pharmaceuticals Friday, accusing the drugmakers of a pay-for-delay scheme to block generic competition for Novartis’ blood pressure drug Exforge (amlodipine and valsartan).

In 2011, the complaint by FWK Holdings claims, Par agreed not to compete in the market Novartis had cornered with Exforge until Sept. 30, 2014, two years after Novartis’ patent expired, while Novartis agreed not to introduce an authorized generic for Exforge for six months after that date. Without this arrangement, the lawsuit claims, one or more generics for Exforge could have been on the market as early as September 2012 and cheaper generics would have comprised most sales.

“Defendants’ anticompetitive Agreement caused harm to the direct purchasers of Exforge by causing them to pay artificially-inflated prices for Exforge and generic versions of Exforge. Plaintiff, and all others similarly situated, were injured and sustained damages in the form of overcharges for branded and generic forms of Exforge as a direct result of Novartis’s and Par’s unlawful Agreement,” the complaint states.