title: ASP2408 and ASP2409, novel CTLA4-Ig variants with CD86-selective ligand binding activity and improved immunosuppressive potency, created by directed evolution.
abstract: The CTLA4-Ig therapeutics abatacept and belatacept inhibit CD28-mediated T cell activation by binding CD80 (B7-1) and CD86 (B7-2) co-stimulatory ligands. Both compounds preferentially bind CD80, yet CD86 has been implicated as the dominant co-stimulatory ligand. Using directed evolution methods, novel CTLA4-Ig variants were created with selective CD86 binding affinity, a property that confers increased immunosuppressive potency and potentially improved efficacy and safety profiles. Relative to abatacept (wild-type CTLA4-Ig), ASP2408 and ASP2409 have 83-fold and 220-fold enhanced binding affinity to CD86 while retaining 1.5-fold and 5.6-fold enhanced binding affinity to CD80, respectively. Improvements in CD86 binding affinity correlates with increased immunosuppressive potencyin vitroandin vivo Our results highlight the power of directed evolution methods to obtain non-intuitive protein engineering solutions and represent the first examples of CD86-selective CTLA4-Ig compounds that have entered clinical trials.
authors.affiliation: Pharmacology Research Laboratories, Drug Discovery Research, Astellas Pharma, Inc., Tsukuba, Ibaraki 3058585, Japan shinsuke.ooshima@astellas.com ekarrer@comcast.net.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Oshima
authors.affiliation: Department of Molecular Biology, Perseid Therapeutics, Redwood City, CA 94063, USA shinsuke.ooshima@astellas.com ekarrer@comcast.net.
authors.forename: Erik E
authors.initials: EE
authors.lastname: Karrer
authors.affiliation: Department of Molecular Biology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Madan M
authors.initials: MM
authors.lastname: Paidhungat
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Margaret
authors.initials: M
authors.lastname: Neighbors
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Chapin
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Rong A
authors.initials: RA
authors.lastname: Fan
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Reed
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Kuoting
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Clifford
authors.initials: C
authors.lastname: Wong
authors.affiliation: Department of Protein Analytics and Pharmaceutics, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Colabrativ, Inc., Orinda, CA 94563, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Whitlow
authors.affiliation: Department of Molecular Biology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Anderson
authors.affiliation: Department of Molecular Biology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Rujuta A
authors.initials: RA
authors.lastname: Bam
authors.affiliation: Department of Molecular Biology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Protein Analytics and Pharmaceutics, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Brent R
authors.initials: BR
authors.lastname: Larsen
authors.affiliation: Department of Process Development and Manufacturing, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Viswanathan
authors.affiliation: Department of Biology and Pharmacology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Devens
authors.affiliation: Department of Molecular Biology, Perseid Therapeutics, Redwood City, CA 94063, USA.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Bass
authors.affiliation: Pharmacology Research Laboratories, Drug Discovery Research, Astellas Pharma, Inc., Tsukuba, Ibaraki 3058585, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Higashi
mesh_terms: D000069594:Abatacept / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D051940:B7-2 Antigen / Q000378:metabolism*; D019556:COS Cells; D002522:Chlorocebus aethiops; D019020:Directed Molecular Evolution; D005260:Female; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D008024:Ligands; D051379:Mice; D008958:Models, Molecular; D011487:Protein Conformation; D013379:Substrate Specificity
chemical_list: C000619913:ASP2409; D051940:B7-2 Antigen; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D008024:Ligands; D000069594:Abatacept
keywords: costimulation blockade; next-generation protein therapeutics; phage display; rheumatoid arthritis; transplantation