The upcoming antitrust trial over Cephalon's alleged reverse-payment settlements with generic drug companies needs to be bifurcated at the liability phase, a federal judge has ruled.

U.S. District Court Judge Mitchell Goldberg of the Eastern District of Pennsylvania determined that the liability portion of the trial will need to be split into violation and causation phases in order to allow jurors to hear key evidence about the validity of the pharmaceutical patent underlying the case without prejudicing the defendants.

The trial stems from claims that brand-name drugmaker Cephalon entered into settlements with four generic drug companies regarding its patent for the drug Provigil. The plaintiffs, which include generic drugmaker Apotex Inc. and a group of pharmaceutical retailers, claim the settlements were only entered into to delay competing generic versions of Provigil from getting to market sooner. Jury selection is set to begin Monday.