In Coalition for Affordable Drugs V LLC v. Biogen MA Inc., the PTAB denied an obviousness challenge of a patent covering methods of treating multiple sclerosis using a particular dosage of known fumarate drugs.  The patent at issue—U.S. Patent No. 8,399,514—is listed in the Orange Book for Biogen’s Tecfidera^® product.

The claims of the ’514 patent require administering about 480 mg per day of dimethyl fumarate (DMF), monomethyl fumarate, or a combination thereof.  In support of its obviousness challenge, Petitioner relied on Kappos, a prior art reference describing the administration of DMF in doses of 120 mg, 360 mg, and 720 mg per day.  Kappos found that the 120 mg and 360 mg doses did not demonstrate significant efficacy in treating MS and concluded that DMF exhibits dose-dependent efficacy.

The Board agreed with Petitioner that one of skill in the art would have had ample reason to use routine experimentation to determine optimum dosing.  Further, based on the reported side-effects of fumarates, one skilled in the art would have been motivated to examine doses between 360 mg and 720 mg per day to identify an effective dose with fewer side effects.  The Board also concluded that one of skill in the art would have had a reasonable expectation of success in determining therapeutically effective doses.

Despite these findings, the Board determined that the Petitioner failed to demonstrate that the claims were obvious in light of Biogen’s showing of unexpected results. Biogen’s experts explained that a dose of 480 mg per day was similarly efficacious to 720 mg per day, and that this was unexpected because one of skill in the art would expect the efficacy of a 480 mg dose to be more similar to that of a 360 mg dose, which is not effective.  The Board found that the Petitioner did not effectively address this showing and held that this showing overcame the prima facie obviousness of the claims.

Secondary considerations have not been found sufficient to overcome many claims that are prima facie obvious, but this case suggests that unexpected results may fall into a category of its own.