Biogen's Tecfidera patent contingency plan falls flat amid sputtering Aduhelm launch

Biogen’s contingency plan to keep Tecfidera generics at bay has fallen flat.

After a U.S. appeals court in November declined to resurrect a key patent on Biogen’s multiple sclerosis (MS) blockbuster dubbed '514, the company filed for a rehearing. Wednesday, the U.S. Court of Appeals for the Federal Circuit rejected (PDF) the biotech’s bid, leaving the door open for generics to continue chipping away at Biogen’s once-stalwart MS franchise.

Biogen’s dispute with Viatris—formerly Mylan—hinges on what’s known as “written description,” which asserts patent holders must sufficiently describe the technology they wish to patent.

Viatris originally argued that the claims of Biogen’s '514 patent were invalid “for lack of written description support in the specification,” court documents filed this week show.

Biogen’s '514 patent was originally set to expire in 2028, but in June 2020, U.S. District Judge Irene Keeley ruled in Mylan’s favor, invalidating the Tecfidera patent and putting years of monopoly sales at risk.

Biogen promised to appeal at the time. Nevertheless, Viatris moved forward with the launch of its Tecfidera copycat in August 2020. Viatris’ product is the first oral MS generic to hit the market. Multiple other generics outfits, such as Lupin and Glenmark, are waiting to launch their own versions of Biogen’s drug, Endpoints News points out.

In the wake of this week’s appeals court decision, Biogen has the option to appeal to the Supreme Court. Still, the damage from Tecfidera copycats is already taking its toll.

“Multiple Tecfidera generic entrants are now in the U.S. market and have deeply discounted prices compared to Tecfidera,” the biotech said in a securities filing last month. “The generic competition for Tecfidera has significantly reduced our Tecfidera revenue and is expected to continue to have a substantial and increasing negative impact on our U.S. Tecfidera revenue in the future.” 

In 2021, Tecfidera clinched $680.6 million in the U.S. and $1.27 billion abroad for total sales of $1.95 billion. It’s already apparent how big a bite U.S. generics have taken out of Biogen’s MS franchise, however. Back in 2020, Tecfidera generated $2.67 billion in the U.S. alone, with global sales for the year clocking in at $3.84 billion.

Meanwhile, the appeals court’s decision wasn’t unanimous. In a dissenting opinion, three judges said the rejection “let a panel majority opinion stand that imports extraneous considerations into the written description analysis and blurs the boundaries between the written description requirement and the other statutory requirements for patentability.

“In doing so, the court has contributed to the muddying of the written description requirement,” the judges contended. 

Biogen's Tecfidera woes come as the company's Alzheimer's disease med, Aduhelm, flounders. The drug has faced a safety controversy and early skepticism from payers. In its first three months on the market, Aduhelm reaped just $300,000. The drug followed that performance with a $1 million sales haul in the fourth quarter of 2021.