Can a generic drug maker be held liable for failure-to-warn claims because its version of a popular drug gained U.S. Food and Drug Administration recognition as the industry standard?

That’s the theory plaintiffs lawyers in Atlanta have been pushing in a wrongful death suit against generic manufacturer Mylan and brand name giant Pfizer. The plaintiffs argued that because Mylan’s maximum strength anti-seizure drug, phenytoin, had become the “reference listed drug” in a particular dosage class, they should be able to avoid dismissal under the U.S. Supreme Court’s decision last June in Pliva v. Mensing. In Mensing, as we’ve reported, the Justices ruled 5-4 that state law tort claims against generics are preempted because generics must follow federal labeling guidelines approved for brand-name manufacturers.

The theory didn’t go over well with Atlanta federal district court senior judge Marvin Shoob. In a 39-page opinion issued last Thursday, he rejected the plaintiffs’ arguments and dismissed most of their claims against Mylan and Pfizer. [Hat tip: FDA Law Blog.]

The plaintiffs originally filed their claims in Fulton County state court in January 2011, and the case was removed to federal court in September. They accused Mylan and Pfizer of causing the death of George Frazier Jr. by designing and manufacturing a defective product and failing to warn of the side effects of phenytoin. The plaintiffs–Frazier’s estate, widow, and children– alleged in their complaint that Frazier died in March 2008 after having an adverse reaction to Mylan’s generic phenytoin. Pfizer markets phenytoin under the brand name Dilantin.

DLA Piper and Tucker Ellis & West represent Pfizer. Mylan is represented by Nelson Mullins & Scarborough. The plaintiffs are represented by Childers, Schlueter & Smith.

Mylan argued in its motion to dismiss that Frazier had taken the 100 mg version of phenytoin, whereas only Mylan’s 300 mg version had been recognized by the FDA as the reference listed drug. The company asserted that it was required by Mensing to follow labeling requirements for Pfizer’s Dilantin, and that changing its label would make it “impossible for Mylan to comply with the requirements imposed by the supreme law of the land.”

The plaintiffs countered in their response to Mylan’s motion to dismiss that “[t]he Mensing Court did not address and, therefore, does not preempt any claims arising against a generic manufacturer that is an RLD holder of another drug product with the same active ingredient, like Mylan is in the present case.”

Judge Shoob ultimately agreed with the defense that, because the FDA considered each strength of a drug separately, Mylan did not have to change the label on the 100 mg product to conform to requirements for the 300 mg product. “FDA designated 300-mg as the RLD for the 300-mg strength dosage of phenytoin, not for 100-mg phenytoin,” he concluded. Judge Shoob also wrote that plaintiffs did not cite any authority for the proposition that Mylan now had the same rights and obligations as a brand name manufacturer simply because it made a RLD version of the phenytoin. The plaintiffs claims against Mylan, he ruled, were preempted under Mensing.

It wasn’t all bad news for the plaintiffs, though. Judge Shoob ruled that claims against Pfizer for wrongful death, pain and suffering and joint and several liability could proceed.

This latest skirmish between the plaintiffs’ bar and generic drug manufacturers over the limits of the Mensing decision comes on the heels of an eventful November, when both sides claimed at least partial victories. Several companies, including Teva Pharmaceuticals USA, Inc., Mylan, Inc., and Barr Pharmaceuticals succeeded in persuading a federal judge in Newark, N.J. to dismiss failure-to-warn claims brought by approximately 100 plaintiffs in the Fosamax MDL. Teva and Sandoz came up short that same month, however, when a Philadelphia Common Pleas Court judge allowed 2,000 suits over the heartburn drug Reglan to continue, holding that Mensing was limited to labeling claims only.

Pfizer lawyer Ann Byrd of DLA Piper did not respond to requests for comment. Stephen Brooks of Nelson Mullins, who represents Mylan, referred us to his co-counsel Matthew Wendler of Pietragallo Gordon Alfano Bosick & Raspanti, who was unavailable to comment. Plaintiffs lawyer Andrew Childers of Childers & Schleuter also did not respond to requests for comment.