Drug Discovery Catch-22: A Healthy Dose of Written Description

To satisfy the written description requirement under 35 U.S.C. 112, a patent specification must describe the claimed invention in such sufficient detail that a person of skilled in the art (POSA) can reasonably conclude that the inventor had possession of the claimed invention. In Biogen International GmbH v. Mylan Pharmaceuticals Inc., at issue is whether the specification provides adequate written description for method of use claims to a specific dosage strength, 480 mg/day, of dimethyl fumarate (DMF480). On November 30, 2021, in a split decision, the Federal Circuit affirmed the district court decision finding the method claims of the ‘514 patent invalid for lack of written description.