Hagens Berman filed an antitrust lawsuit against Takeda and Par on behalf of a proposed class of direct purchasers of Amitiza and its generic equivalents regarding a patent infringement settlement, through which Takeda is alleged to have paid Par to delay the launch of its generic Amitiza product, allegedly resulting in hundreds of millions in overcharges to the proposed class.

Case Status
U.S. District Court for the District of Massachusetts
Case Number
1:21-cv-11057-GAO; 1:21-cv-11255-GAO
Takeda Pharmaceutical Company Limited
Takeda Pharmaceuticals U.S.A. Inc.
Par Pharmaceutical Inc.
File Date


The plaintiffs in the class-action lawsuit, FWK Holdings LLC and KPH Healthcare Services Inc., each filed lawsuits against drugmakers Takeda and Par on behalf of themselves and other direct purchasers of Amitiza and the drug’s generic counterparts.

The lawsuits allege that Takeda settled patent infringement litigation with Par Pharmaceuticals and paid off Par with an anticompetitive “reverse payment” in violation of federal antitrust laws, aptly named “reverse” because Takeda brought the patent suit, yet paid Teva in the end.


According to the complaint, the alleged reverse payment took the form of Takeda’s promise not to launch a competing generic version of Amitiza when Par eventually came to market. This no-authorized generic agreement is allegedly manifest through the royalty payment structure in the settlement, which makes it economically irrational for Takeda to launch its own generic product when Par is allowed to do so.

According to the complaint, in exchange, Par agreed to drop its patent challenge, forego launching at-risk, and agreed to delay coming to market for five and a half years. The Supreme Court forbids such large and unjustified reverse payments.

While attorneys believe that defendants attempted to conceal their unlawful agreement through an allegedly superficial reservation in the settlement agreement that Takeda may launch its own authorized generic product, recent authority in the District of Massachusetts rejects the argument that such a reservation can absolve anticompetitive conduct manifest through the royalty provisions in the agreement that contradict that reservation.

The complaints allege this no-AG (authorized generic) agreement was confirmed in 2021, when Par launched its generic Amitiza product and Takeda did not launch a competing authorized generic.


Hagens Berman is one of the most successful litigation law firms in the U.S. taking on pharmaceutical companies and has achieved total settlements valued at more than $320 billion on behalf of plaintiffs.


Defendants Move to Dismiss

Defendants moved to dismiss plaintiffs’ complaints. The plaintiffs have opposed that motion. Briefing on the matter is now complete and the parties await a decision. 

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