A class can’t be decertified unless there are substantial changes to the facts of a case, nor can it be decertified once a partial ruling has been made as to the merits of the case, an attorney for a class suing over the off-label marketing of epilepsy and neuralgia drug Neurontin argued before the Pennsylvania Superior Court in Philadelphia Wednesday.

John K. Weston of Sacks & Weston in Jenkintown, Pa., represents the former class led by Gregory Clark and Linda Meashey in Clark v. Pfizer Inc. He argued Philadelphia Common Pleas Court Judge Mark I. Bernstein improperly decertified the class in February — a month before trial. Weston said depositions of a sampling of Pennsylvania doctors who said they prescribed the drug for off-label uses but weren’t influenced to do so by any Pfizer marketing campaign were not enough to overturn the class. He said it doesn’t matter if the doctors said they weren’t affected by such a campaign because that is an issue for the jury to decide.