Drugmaker Celgene has agreed to pay $55 million to settle a class action lawsuit accusing it of violating antitrust laws by interfering with the development of generic versions of two of its cancer drugs.

Plaintiffs in the class action, a group of labor unions and other end payers, moved Wednesday for preliminary approval of the settlement. The suit claimed Celgene repeatedly hiked the prices of its drugs Thalomid and Revlimid while pursuing an anti-competitive scheme against at least 11 makers of generic drugs. The settlement was reached after negotiations with mediator Jed Melnick of JAMS in New York.