Addressing the threshold question of whether a patent is eligible for post-grant review (PGR), the Patent Trial and Appeal Board (Board or PTAB) denied institution of the PGR because the petitioner had not adequately demonstrated that the claims at issue were not enabled or lacked written description in any non-provisional parent applications. Merck Sharp & Dohme Corp. v. Wyeth LLC, Case Nos. PGR2017-00016; PGR2017-00017 (PTAB, Oct. 20, 2017) (Obermann, APJ).

Merck filed two PGR petitions seeking to invalidate claims of a patent owned by Wyeth that was related to an immunogenic composition comprising polysaccharide-protein conjugates containing capsular polysaccharides prepared from different S. pneumoniae serotypes.

PGR is only available for patents that are subject to the America Invents Act (AIA), which applies only to patents and applications that include at least one claim having an effective filing date on or after March 16, 2013. While the challenged patent issued from a non-provisional application filed after March 16, 2013, it claimed priority to several non-provisional parent applications filed before March 16, 2013. 

To establish standing to file the PGR, Merck argued that at least one challenged patent claim was not entitled to a pre-March 16, 2013, priority date. First, Merck argued that none of the claims were enabled by any of the non-provisional parent applications and thus were not entitled to a pre-AIA priority date. Second, Merck argued that two of the challenged claims lacked written description support in any non-provisional parent application and were not entitled to a pre-AIA priority date. The PTAB disagreed on both grounds and denied the petitions.

As to enablement, the PTAB found that the petitions did not sufficiently demonstrate that a person of ordinary skill in the art could not identify the structure of any particular serotype without undue experimentation. The PTAB noted that Merck’s failure to adequately address the Wands factors supported denial of the PGR petitions. The PTAB also found that a declaration submitted in support of the petitions relied on “unsupported opinions” and “unsubstantiated calculation,” and that Merck and the declarant had not explained why experiments would be undue. The PTAB concluded that the examples set forth in the provisional applications provided adequate guidance enabling the “generation and characterization of a representative multivalent composition of the granted claims.”

The PTAB further found that Merck failed to sufficiently demonstrate lack of written description support for the “antigens” of the two identified claims. Agreeing with Wyeth, the PTAB concluded that Merck’s argument that the provisional applications failed to support certain unclaimed features of the invention (such as buffer or protein concentrations) was meritless.