Federal Circuit Remands to PTAB to Further Consider Pfizer's Motion to Amend Claims

March 13, 2024

In a recent ruling regarding Pfizer's pneumococcal vaccine patent (U.S. Patent No. 9,492,559), the Federal Circuit upheld most of the Patent Trial and Appeal Board’s (PTAB) decision to invalidate portions of Pfizer's ‘559 patent as obvious. The PTAB’s invalidation of the ‘559 patent occurred over five IPRs by Merck Sharp & Dohme Corp., Sanofi Pasteur Inc. and SK Chemicals Co.

In particular, the Federal Circuit affirmed the PTAB’s conclusion that claims 1-45 are unpatentable. The Federal Circuit also affirmed the PTAB’s denial of Pfizer’s contingent motions to amend by adding proposed claims 46, 47, and 50-52. However, the Federal Circuit vacated and remanded to the PTAB to further consider Pfizer’s motions with regard to proposed claims 48 and 49.

Here, the Federal Circuit concluded that the PTAB did not adequately address the limitations in proposed claims 48 and 49. These claims further required that the composition exhibit more than a 2-log increase above baseline in serum IgG levels across all serotypes within the claimed composition of claim 46, and that the composition must also exhibit such an increase with respect to certain serotypes for claims 48 and 49.

Notably, with respect to the Sanofi Decision, the Federal Circuit asserted: “[t]he only mention of those claims in that decision is a conclusory statement, prior to any analysis, that the Board determined that ‘claims 46 and 48-52 would have been obvious over the combination of Hausdorff, Merck-086, GSK-711, and the knowledge of the skilled artisan.’” The PTAB in the subsequent explanation does not actually address the additional claim limitations for claims 48 and 49, and instead solely focuses on the elements of claim 46.

Similar deficiencies with respect to claims 48 and 49 are present in the other IPR decisions. In particular, the Federal Circuit found the PTAB discussed the obviousness to incorporate the glycoconjugates into a pneumococcal vaccine, but not whether it would have been reasonably expected that the compositions exhibit the claimed 2-log IgG increase across all serotypes recited in proposed claims 48 and 49.

The ruling underscores the necessity to review every analysis and conclusion by the PTAB to determine whether a “reasoned basis” has been provided for deeming a claim unpatentable. The Federal Circuit, in this case, believes the PTAB has not, and that “it abused its discretion in denying Pfizer’s motions to amend.” Furthermore, this provides another possibility for Pfizer to amend by adding proposed claims 48 and 49 should the PTAB come up short in providing said reasoned basis.

This case serves as a reminder to practitioners to argue important features separately in a response to an IPR, especially when recited in separate claims. In assessing the PTAB decision, practitioners can review whether the PTAB sufficiently addressed those distinct features and identify if there is strong ground for appealing to the Federal Circuit based on any deficiencies in the PTAB conclusions.