United States Court of Appeals for the Federal Circuit ______________________

PFIZER INC., Appellant

v.

SANOFI PASTEUR INC., SK CHEMICALS CO., LTD., Appellees

KATHERINE K. VIDAL, UNDER SECRETARY OF COMMERCE FOR INTELLECTUAL PROPERTY AND DIRECTOR OF THE UNITED STATES PATENT AND TRADEMARK OFFICE, Intervenor ______________________

2019-1871, 2019-1873, 2019-1875, 2019-1876, 2019-2224 ______________________

Appeals from the United States Patent and Trademark Office, Patent Trial and Appeal Board in Nos. IPR2017-02131, IPR2017-02132, IPR2017-02136, IPR2017-02138, IPR2018-00187. ______________________

Decided: March 5, 2024 ______________________

JOHN P. SCHEIBELER, White & Case LLP, New York, NY, argued for appellant. Also represented by DIMITRIOS T. DRIVAS, AMIT THAKORE; ELIZABETH K. CHANG, CATALIN Case: 19-1871 Document: 146 Page: 2 Filed: 03/05/2024

2 PFIZER INC. v. SANOFI PASTEUR INC.

SEBASTIAN ZONTE, Los Angeles, CA; HENRY HUANG, Palo Alto, CA.

SIEGMUND Y. GUTMAN, Proskauer Rose LLP, Los Ange- les, CA, argued for appellees. Also represented by JOHN E. ROBERTS, Boston, MA.

MARY L. KELLY, Office of the Solicitor, United States Patent and Trademark Office, Alexandria, VA, argued for intervenor. Also represented by PETER J. AYERS, DANIEL KAZHDAN, FARHEENA YASMEEN RASHEED; SCOTT R. MCIN- TOSH, Appellate Staff, Civil Division, United States De- partment of Justice, Washington, DC. ______________________

Before LOURIE, BRYSON, and STARK, Circuit Judges. LOURIE, Circuit Judge. Pfizer Inc. appeals from five final written decisions of the U.S. Patent and Trademark Office Patent Trial and Ap- peal Board (“the Board”) concluding that claims 1–45 of U.S. Patent 9,492,559 (“the ’559 patent”) are unpatentable. Merck Sharp & Dohme Corp. v. Pfizer Inc., No. IPR2017-02131, 2019 WL 1222935 (P.T.A.B. Mar. 13, 2019) (holding claims 1–10, 16–19, and 38–45 unpatenta- ble) (“’131 Decision”), J.A. 1–81; Merck Sharp & Dohme Corp. v. Pfizer Inc., No. IPR2017-02132, 2019 WL 1220899 (P.T.A.B. Mar. 13, 2019) (same) (“’132 Decision”), J.A. 82–160; Merck Sharp & Dohme Corp. v. Pfizer Inc., No. IPR2017-02136, 2019 WL 1222965 (P.T.A.B. Mar. 13, 2019) (holding claims 11–15 and 20–37 unpatentable) (“’136 Decision”), J.A. 161–216; Merck Sharp & Dohme Corp. v. Pfizer Inc., No. IPR2017-02138, 2019 WL 1220900 (P.T.A.B. Mar. 13, 2019) (same) (“’138 Decision”), J.A. 217–71; Sanofi Pasteur Inc. v. Pfizer Inc., No. IPR2018-00187, 2019 WL 2352182 (P.T.A.B. June 3, 2019) (holding claims 1–45 unpatentable) (“Sanofi Case: 19-1871 Document: 146 Page: 3 Filed: 03/05/2024

PFIZER INC. v. SANOFI PASTEUR INC. 3

Decision”), J.A. 272–360. 1 The Board also denied Pfizer’s contingent motions to amend the claims filed in three of the five IPRs, concluding that proposed claims 46–52, which Pfizer proposed to substitute for claims 1–4, 9, 41, and 42, respectively, were not independently patentable. Sanofi Decision at *27–37; ’131 Decision at *24–33; ’132 Decision at *23–32. For the following reasons, we affirm the Board’s con- clusions that claims 1–45 are unpatentable. We further af- firm the Board’s denials of Pfizer’s motions to amend by adding proposed claims 46, 47, and 50–52. But we vacate those denials as to proposed claims 48 and 49, and remand to the Board for further consideration of those claims. BACKGROUND Pfizer owns the ’559 patent, which is directed to immu- nogenic compositions comprising conjugated Streptococcus pneumoniae capsular saccharide antigens (i.e., glycoconju- gates) for use in pn