US 12,351,622 B2
Modified product of Fc domain of antibody
Ryota Nakao, Kawasaki (JP); Yoshikatsu Izumi, Kawasaki (JP); and Kunihiro Hattori, Kawasaki (JP)
Assigned to BiCA Therapeutics Inc., Kawasaki (JP)
Appl. No. 17/311,085
Filed by BiCA Therapeutics Inc., Kawasaki (JP)
PCT Filed Dec. 5, 2019, PCT No. PCT/JP2019/047620
§ 371(c)(1), (2) Date Jun. 4, 2021,
PCT Pub. No. WO2020/116560, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 2018-228448 (JP), filed on Dec. 5, 2018.
Prior Publication US 2022/0048981 A1, Feb. 17, 2022
Int. Cl. C07K 16/18 (2006.01)
CPC C07K 16/18 (2013.01) [C07K 2317/52 (2013.01); C07K 2317/92 (2013.01); C07K 2319/30 (2013.01)] 2 Claims
 
1. A variant of a parent polypeptide comprising an Fc region of a cat IgG, that shows a higher binding activity to a cat neonatal Fc receptor (FcRn) than a binding activity of the parent polypeptide to a cat FcRn under acidic conditions, wherein the Fc region comprises at least the following amino acid modification:
(i) substitution of the 428-position serine with leucine,
(ii) substitution of the 434-position serine with alanine,
(iii) substitution of the 438-position glutamine with arginine, and
(iv) substitution of the 440-position serine with glutamic acid,
wherein the numbering of amino acid position in the Fc region is based on EU Index of Kabat using Fc region of human antibody as the standard.