IRVINE, Calif.—Allergan has dropped its lawsuit against Valeant Pharmaceuticals International Inc. and Pershing Square Management that was filed in response to Pershing Square’s purchase of Allergan stock just prior to Valeant’s unsuccessful bid for Allergan last year.

The unsuccessful merger of Valeant and Allergan was backed by Pershing Square chief William Ackman, who Allergan accused of insider trading. Allergan sought to prevent Pershing Square’s shares from being voted in a shareholder vote on the proposed Valeant takeover. However, the vote never took place because Allergan was bought by Actavis. Sources say there were no fees as part of the settlement and none of the parties are admitting fault.