Drug maker Pfizer is opposing a plaintiff’s request to have her case remanded back to state court in the Effexor products liability litigation, arguing that California plaintiffs have been joining drug distributor McKesson in order to destroy diversity jurisdiction and prevent manufacturers from keeping cases in federal court.

“Joining McKesson has become a popular tactic for destroying diversity and preventing manufacturer defendants from proceeding in federal court,” defense attorney Mark S. Cheffo, of Quinn Emanuel Urquhart & Sullivan in New York, wrote.

Federal courts can only retain jurisdiction over cases in which there is complete diversity in the citizenship of the parties.

McKesson is joined in nearly every pharmaceutical litigation, but “defendants have no record that plaintiffs have ever proceeded to trial against McKesson.”

The Effexor Multidistrict Litigation, in which plaintiffs allege birth defects were caused by the use of the antidepressant, is pending in front of U.S. District Judge Cynthia M. Rufe of the Eastern District of Pennsylvania.

While Rufe has remanded cases that the defendants removed “based on the fraudulent rejoinder of McKesson,” Pfizer said the remand should be denied this time because “first, plaintiffs’ factual allegations are not sufficient to support a claim against McKesson because they are solely based on McKesson’s alleged relationship with Pfizer, which is irrelevant because Pfizer had no involvement with Effexor … until the very end of the mother plaintiff’s pregnancy with the minor plaintiff. Second, the failure of plaintiffs in other cases to proceed against McKesson following remand, coupled with the deficient pleadings in this case, warrants early discovery of McKesson to determine the propriety of its joinder in this action.”

Pfizer also noted that during a status conference last fall, Rufe commented that she was thinking about ordering preliminary discovery on McKesson after seeing that McKesson was never held liable in her experience.

The fraudulent joinder doctrine kicks in if a plaintiff fails to state a cause of action against a defendant and ”the failure is obvious according to the settled rules of the state,’” court papers said.

The plaintiffs have had no transaction or relationship with McKesson, Pfizer said, and, moreover, a pharmaceutical distributor can’t be held liable for failure to warn under California law.