US 12,344,650 B2
Compositions for increasing half-life of a therapeutic agent in felines and methods of use
William Brondyk, Mansfield, MA (US); Brett Chevalier, Melrose, MA (US); Juergen Horn, Marblehead, MA (US); and Madhusudan Natarajan, Waban, MA (US)
Assigned to Invetx, Inc., Boston, MA (US)
Filed by Invetx, Inc., Boston, MA (US)
Filed on Oct. 12, 2022, as Appl. No. 18/046,082.
Application 18/046,082 is a continuation of application No. 17/355,839, filed on Jun. 23, 2021, granted, now 11,498,953.
Claims priority of provisional application 63/143,720, filed on Jan. 29, 2021.
Claims priority of provisional application 63/050,535, filed on Jul. 10, 2020.
Prior Publication US 2023/0090405 A1, Mar. 23, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C07K 14/705 (2006.01); A61K 38/00 (2006.01)
CPC C07K 14/70503 (2013.01) [A61K 38/00 (2013.01); C07K 2317/52 (2013.01)] 18 Claims
 
1. A polypeptide comprising a feline IgG Fc region variant, wherein the polypeptide comprises (i) an amino acid substitution at a position that corresponds to amino acid position 428 of a wild type feline IgG, wherein the amino acid substitution is S428L, and (ii) an amino acid substitution at at least one position selected from the group consisting of:
(a) an amino acid substitution at a position that corresponds to amino acid position 286 of a wild type feline IgG, wherein the amino acid substitution is T286E;
(b) an amino acid substitution at a position that corresponds to amino acid position 311 of a wild type feline IgG, wherein the amino acid substitution is Q311V or Q311K;
(c) an amino acid substitution at a position that corresponds to amino acid position 312 of a wild type feline IgG, wherein the amino acid substitution is D312T;
(d) an amino acid substitution at a position that corresponds to amino acid position 377 of a wild type feline IgG, wherein the amino acid substitution is I377V; and
(e) an amino acid substitution at a position that corresponds to amino acid position 383 of a wild type feline IgG, wherein the amino acid substitution is I383L;
wherein the amino acid position is based on EU numbering, wherein the polypeptide comprises an amino acid sequence that is at least 95% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs: 1 to 3, wherein the polypeptide has increased binding affinity to feline FcRn when compared to an Fc domain of the wild type feline IgG, and wherein the polypeptide binds to feline FcRn at a higher level at pH 6.0 than at pH 7.4.