A U.S. Patent Office board on Wednesday ruled that Biogen's (BIIB) - Get Report patent on its multiple sclerosis drug Tecfidera was valid, beating back a challenge from generic-drug maker Mylan (MYL) - Get Report.
Biogen shares at last check climbed 17% to $330.52 while Mylan was up 2.5% to $22.81.
Mylan had claimed that the active ingredient in Tecfidera,dimethyl fumarate, had been known for years and that the dosage form was predictable. The U.S. Patent Trial and Appeal Board ruled that Mylan had failed to prove its case.
In their decisions, the patent judges said that Mylan had not "demonstrated by a preponderance of the evidence the unpatentability of claims” it challenged.
Tecfidera is Biogen’s top-selling medicine. Last year, Tecfidera generated $4.43 billion, about 30%, of Biogen's total sales.
Biogen said tests indicated the drug didn’t work well at the 360-milligram level and had only a “modest” effect at 720 milligrams.
It was “stunning and unexpected” to learn that changing the dose to the in-between level of 480 milligrams “produces a strong, therapeutic effect,” Biogen lawyer Barbara McCurdy told the board, according to Bloomberg.
The review board agreed, saying there was “strong evidence of unexpected results.”
A Biogen spokesman said Tecfidera "set a new standard in the care of relapsing multiple sclerosis,” adding that "its well-established efficacy and safety profile is supported by more than 415,000 patients who have been treated to date.”
Mylan said in a statement that it disagreed with the board’s decision, saying it "plans to pursue all available options for appeal."
"Mylan is also challenging the validity of this patent in the District Court of West Virginia, with trial having started on Feb. 4 and is ongoing, which includes grounds different from those that were considered by the PTAB," the statement said
The statement noted that other abbreviated-new-drug-application filers are also challenging Biogen in Delaware.
Mylan "continues to believe, based on the law and the facts, that Biogen’s ‘514 patent is invalid and will continue its challenges in both the district court and the Federal Circuit to remove this patent from blocking generic competition to Tecfidera," the statement said.