IPR finding that Mylan did not show Merck’s DP-IV claims invalid for anticipation or obviousness affirmed

Mylan Pharmaceuticals Inc. v. Merck Sharp & Dome Corp.

Docket No. 2021-2121 (IPR2020-00040) (https://cafc.uscourts.gov/opinions-orders/21-2121.OPINION.9-29-2022_2010851.pdf)

LOURIE, REYNA, STOLL

September 29, 2022

Brief Summary:   Board IPR finding that Mylan did not show Merck’s DP-IV claims invalid for anticipation or obviousness affirmed. Summary:  Mylan appealed USPTO (“Board”) finding Merck’s claims 1-4, 17, 19 and 23 of US 7,326,708 directed to sitagliptin dihydrogenphosphate (DPH) (a dipeptidyl peptidase-IV (“DP-IV”)) were not invalid for anticipation or obviousness.  The ‘708 patent is listed on the FDA’s Orange Book for Steglujan (for glycemic control) as well Janumet, Janumet XR, Januvia, and Juvisync for treating Type II diabetes.  The ‘708 patent claims DP-IV structurally including one asymmetric carbon as well as the (R)- and (S)-configurations as well as the crystalline monohydrate form of the (R)-configuration in dependent claims (2, 3 and 4, respectively).  Mylan petitioned for IPR of the challenged claims in view of the Merck-owned ‘498 PCT publication and its equivalent US Pat. No. 6,699,871 (collectively referred to as “Edmondson”) which “discloses a genus of DP-IV inhibitors and 33 species, one of which is sitagliptin” and “that pharmaceutically acceptable salts can be formed using one of eight ‘[p]articularly preferred’ acids” (including phosphoric acid) that “may exist in crystalline forms, including as hydrates”.  In addition to Edmondson, Mylan argued for obviousness when combined with Brittain and Bastin, both generally relating to crystalline and salt forms of pharmaceutical drugs.  “‘[T]he Board determined that there was no express disclosure of all of the limitations of the 1:1 sitagliptin DHP salt in Edmondson, and that Mylan could not fill in the gaps by arguing that a skilled artisan would “at once envisage’ what is missing” and that “Mylan had not proven an inherent disclosure of the 1:1 sitagliptin DHP salt in Edmondson, and that evidence, both experimental and from the technical literature, undeniably showed that 1:1 sitagliptin DHP does not form every time sitagliptin and DHP were reacted.”  The Board also found that “Edmondson was not a 35 U.S.C. § 102(a) reference, but merely a 35 U.S.C. § 102(e) (pre-AIA) reference” (e.g., “Merck had reduced to practice at least as much, and in fact more, of the claimed subject matter than was shown in Edmondson”) and the section 103(c)(1) (pre-AIA) common ownership exception applied.  The Board also found Mylan did not show the references disclose the claimed (R), (S) or racemic mixtures (e.g., “no rationale to explain” a motivation to produce those forms).  The FC panel found the Board’s decision to be supported by substantial evidence (e.g., no express or inherent disclosure of “the 1:1 sitagliptin DHP salt” in Edmondson (In re Petering, CCPA 1962); “…the Board’s finding that it does not disclose a hydrate of that salt was likewise supported by substantial evidence.  We therefore agree with the Board that Merck reduced to practice “more . . . than what is shown in [Edmondson] for the claimed subject matter.”)   The FC panel also agreed with the Board’s no obviousness decision (e.g., “no motivation to combine Edmondson and Bastin”, “no reasonable expectation of success in combining”, “no expected or theoretical benefit”, “did not err in its evaluation of purported objective indicia”).  The Board’s decision was therefore affirmed.