Last week, the U.S. Court of Appeals for the Federal Circuit issued a precedential opinion in Allergan USA, Inc. v. MSN Laboratories Private Ltd, No. 2024-1061 (Aug. 13, 2024), reversing the district court’s invalidity findings.
Allergan sells the drug Viberzi comprised of eluxadoline, which mitigates symptoms of IBS. Sun sought FDA approval to sell a generic substitute to Viberzi and, as required, Sun statutorily certified that Allergan’s ’356 patent is invalid or not infringed by Sun’s generic product. Allergan filed suit alleging Sun’s product would infringe claim 40 of the ’356 patent. Allergan amended its complaint to include claims for infringement of other, later-filed and later-issued Allergan patents in the ’356 patent family. In a bench trial, Sun argued claim 40 of the ’356 patent was invalid for obviousness-type double patenting (“ODP”) and the asserted claims of the other patents were invalid for lack of written description support for a formulation that does not include a glidant. The district court agreed with both arguments and entered final judgment of invalidity of all asserted claims. Allergan appealed.
The Federal Circuit reversed. On the issue of ODP, the Court held, as a matter of law, a first-filed, first-issued, later-expiring claim cannot be invalidated by a later-filed, later-issued, earlier-expiring claim having a common priority date. The Court explained that the purpose of the prohibition against ODP is to prevent unjustified time extensions of patent exclusivity. Here, the ’356 patent does not extend or prolong the monopoly on eluxadoline. Rather as the first-filed, first-issued patent in its family, the ’356 patent (with its patent term adjustments) sets the maximum period of exclusivity for the claimed subject matter and patentably indistinct variants. The Court rejected Sun’s assertion that the Court held otherwise in Cellect, noting Cellect did not address under what circumstances a claim can properly serve as an ODP reference. On the issue of written description, the Court held the district court clearly erred in concluding there was no support for a formulation that does not include a glidant. As written, the Court opined, the specification contemplates at least two embodiments in which a glidant is not required. Moreover, the specification attributes no particular function or significance to the presence of a glidant that would suggest it is essential or otherwise necessary to the invention. Judge Dyk dissented-in-part, explaining he found no clear error in the district court’s written description finding.
Coauthored by Rachel Zimmerman Scobie & Henry Adebisi.
