Biogen obtained a patent for treatment of Multiple Sclerosis (MS) using DMF, a fumaric-acid ester compound, at a specific dose of 480 mg/day (DMF480) under the brand name Tecfidera.

The patent specification was found to “cast[] a wide net for a myriad of neurological disorders, including neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson’s disease, Alzheimer’s disease, and Huntington’s disease; demyelinating neurological diseases, such as various forms of MS and at least twenty-eight other disorders related to demyelination; polyneuritis; and mitochondrial disorders with demyelination.” The specification only disclosed a single DMF-dosage paragraph with an overall DMF dosage range of 100–1,000 mg/day. The one and only reference to DMF480 in the entire specification was at the bottom end of the spectrum of a DMF 480–720 mg/day range. Subsequent testing revealed that dosages of DMF120 and DMF360 were ineffective in treating MS, but dosages of DMF480 and DMF720 were effective.

The district court found after a bench trial that the specification did not reasonably convey that the inventors had “actually invented” a method of treating MS with a therapeutically effective dose of DMF480 as of the patent’s filing date. Further, the district court found that Biogen’s witness testimony was “neither credible nor persuasive.”

The majority of the Federal Circuit panel, Judges Reyna and Hughes, affirmed the district court. The majority dismissed Biogen’s “anchoring” argument based on the disclosed 480-720 mg/day range, stating that “[n]ot only does the specification anchor an ineffective dose, it also expands the purported range of therapeutic efficacy from DMF100 and DMF200 (doses that a skilled artisan would expect to be ineffective) to DMF1,000 (a dose well above the therapeutically effective DMF720 mg/day dose)” and that reciting “several DMF doses in the 100–1,000 mg/day range as ‘effective’ without even identifying a target disease is further indicative that the inventors were not in possession of a complete and final invention” when they filed their patent application. Further, the majority deferred to district court’s credibility findings. The dissent, Chief Judge O’Malley, felt that the district court legally erred by conflating therapeutic and clinical efficacy and would have remanded the case to the district court for further consideration.