Analyzing patent validity requires consideration of the circumstances at the time of the patent's filing. For example, when deciding whether patent claims are invalid as anticipated or obvious, one must look at the available prior art and knowledge of a person of ordinary skill in the art available at the time of the patent's earliest effective filing date. The recent decision In re ENTRESTO is a reminder that this timing perspective also applies to written description and enablement analyses.
In re ENTRESTO1 is a recent decision of the U.S. Court of Appeals for Federal Circuit ("Federal Circuit" or "CAFC") relating to a number of consolidated patent infringement actions filed by Novartis Pharmaceuticals against several generic drug manufacturers ("the Generics") in response to the Generics' filing of Abbreviated New Drug Applications ("ANDA") seeking approval to market and sell generic versions of Novartis's highly profitable and patented drug ENTRESTO', which was developed in the early 2000s for treating heart failure.
This case illustrates a common dilemma pharmaceutical companies face: the conflict between early patent filing and lengthy drug development. While filing a patent application early can secure a competitive advantage by preempting rivals, it often takes many years of further development and testing before a drug receives market approval from the U.S. Food and Drug Administration. During the course of developing ENTRESTO', Novartis filed multiple patent applications directed to incremental improvements made over the general concept of combining two types of drugs for reducing blood vessel constriction to prevent and treat heart failure. US Patent 8,101,659 ("the '659 Patent") is an earlier-filed patent in Novartis's patent portfolio covering ENTRESTO'. Having an effective filing date of January 17, 2002, the '659 Patent's sole independent...
