After nearly a decade of mass tort litigation in New Jersey, Roche Holding AG won an appeals court ruling on Monday that could help the company stamp out claims that it didn’t adequately warn the public of side effects associated with its acne treatment Accutane.

An intermediate appeals court in Trenton reversed a 2010 verdict that Roche should pay $2.1 million to California resident Gillian Gaghan, who developed inflammatory bowel disease after using Accutane to treat her severe acne. Gaghan’s doctor had testified that he would have prescribed the drug even if Roche’s warning label had contained all the disclosures proposed by Gaghan’s lawyers. Based on that testimony, the appeals court decided the case in favor of Roche on the grounds that Gaghan couldn’t possibly show that the allegedly inadequate warnings caused her IBD.

The decision is likely worth a lot more than $2.1 million to Roche, which is represented on appeal by Paul Schmidt and Michael Imbroscio of Covington & Burling and Michelle Bufano of Gibbons PC. Proximate causation has been a central issue in the roughly 8,000 Accutane cases consolidated before a state court judge in Atlantic City. Roche now has more leverage if it decides to strike a comprehensive settlement. And Monday’s victory could help the company reverse unfavorable verdicts in four bellwether cases that are now pending before the same appeals court, including a monster $25 million verdict from 2010.

Monday’s ruling, issued by the Superior Court of New Jersey’s Appellate Division, also affirms defense verdicts in two Accutane cases tried in parallel with the Gaghan case. The plaintiff in one of those cases is the actor James Marshall, known for small roles in Twin Peaks and A Few Good Men. Marshall argued unsuccessfully at a 2011 trial that taking Accutane caused IBD that destroyed his once-promising career. Fellow actor Martin Sheen had testified during the trial that Marshall was destined for great things until his career was sidetracked by health problems in the 1990s.

The Gaghan verdict isn’t the first Accutane plaintiffs victory to go up in smoke on appeal. In 2007, a state court jury in Florida returned a $7 million verdict against Roche in one of the few Accutane cases not consolidated into the mass tort litigation in New Jersey. The Florida District Court of Appeal, First District reversed that verdict in 2009 on causation grounds, based on testimony from the plaintiff’s doctor that he too would have prescribed Accutane even if the drug caused IBS in rare cases.

“From the beginning of this litigation, Roche has pressed the common-sense principle that a plaintiff can’t prevail if his or her doctor understood the risk from our warnings and would still prescribe Accutane, a principle that will fundamentally reshape the issues in this litigation,” Roche spokesperson Tara Iannuccillo said in a statement on Monday.

Covington & Burling’s Schmidt argued the appeal for Roche. In addition to Covington & Burling, Roche was represented at trial by Orlando Richmond Sr. of Butler Snow, Russell Hewit of Dughi, Hewit & Domalewski, Cedric Evans of Bowman & Brooke and Colleen Hennessey of Peabody & Arnold.

The plaintiffs firms driving the Accutane litigation include Seeger Weiss, Hook & Bolton and Beggs & Lane. David Buchanan of Seeger Weiss, who argued the New Jersey appeal for the plaintiffs, didn’t immediately return a call seeking comment.

Note: This story was updated on Aug. 5 to clarify and add details concerning Roche’s trial and appellate counsel.