Sharing Active Moiety With an FDA-Approved Product Is Not Enough to Be Considered an Approved Product for the Purposes of Patent Term Extension Under 35 U.S.C. § 156

| Serah Friedman, Ph.D.Kendall Loebbaka


Before Lourie, Moore, and Chen.  Appeal from the U.S. District Court for the District of Delaware

Summary: If a claimed product is not the active ingredient of an FDA-approved product, or an ester or salt of that active ingredient, there is no patent term extension available under the Hatch-Waxman Act (35 U.S.C. § 156).

Biogen obtained a patent and FDA approval for dialkyl fumarates (DMF) to treat multiple sclerosis, marketed as Tecfidera®.  During administration, DMF metabolizes to monomethyl fumurate (MMF).  Banner sought to market an MMF pill to treat multiple sclerosis.  Biogen sued Banner for patent infringement.  Banner moved for a judgment of non-infringement, arguing that § 156(b)(2) limits the scope of the patent at issue to methods of using the approved product, which is limited to DMF, its salts, or its esters.  MMF is not a salt or ester of DMF.  Biogen argued that § 156(b)(2) does not limit extension of a method of treatment to uses of the approved product (DMF), but to uses within the original scope of the claims (which includes MMF).  Additionally, Biogen argued that § 156 encompasses any compound that shares an “active moiety” with an approved product, which would include MMF.  The District Court rejected Biogen’s arguments and granted a judgment of non-infringement.

The Federal Circuit affirmed the District Court.  The Federal Circuit held that § 156(b)(2) limits the scope of the patent extension to “any use approved for the product,” and further, for method of treatment patents, to uses also “claimed by the patent.”  The Federal Circuit noted that 156(f) defines a “product,” as “the active ingredient of… a new drug… including any salt or ester of the active ingredient.”  The Federal Circuit held that this definition of “product” has a plain and ordinary meaning that is not coextensive with “active moiety.”  Since MMF is not the active ingredient of the approved product or the ester or salt of that active ingredient, the patent term extension under § 156 does not extend to the use of MMF. 

Editor: Paul Stewart