JPWO2021212084A5 - - Google Patents

Claims (21)

1. A modified IgG comprising a feline IgG constant domain comprising a single amino acid substitution compared to a wild-type feline IgG constant domain, said single amino acid substitution being at amino acid residue 428 as numbered according to the EU index in Kabat;
The modified IgG , wherein the single amino acid substitution is a substitution of serine at position 428 with leucine (S428L) . The modified IgG of claim 1 , wherein the wild-type feline IgG constant domain comprises the amino acid sequence set forth in SEQ ID NO:3. 2. The modified IgG of claim 1, wherein the modified IgG having a feline IgG constant domain has a higher affinity for FcRn than an IgG having a wild-type feline IgG constant domain. The modified IgG of claim 1 , wherein the modified IgG having a feline IgG constant domain has a higher half-life than an IgG having a wild-type feline IgG constant domain . The modified IgG of claim 1 , wherein the modified IgG comprises an Fc constant region having a CH2 or CH3 domain or a combination thereof . The modified IgG of claim 1 , wherein the feline IgG constant domain comprises the amino acid sequence set forth in SEQ ID NO:1. 1. A modified IgG comprising a feline IgG constant domain comprising at least one amino acid substitution compared to a wild-type feline IgG constant domain, said substitution being at amino acid residue 434 as numbered according to the EU index in Kabat;
A modified IgG , wherein the substitution is a substitution of serine at position 434 with histidine (S434H) . 8. The modified IgG of claim 7, wherein the wild-type feline IgG constant domain comprises the amino acid sequence set forth in SEQ ID NO:3. The modified IgG of claim 7 , wherein the feline IgG constant domain comprises another substitution, said another substitution being at amino acid residue 428. 10. The modified IgG of claim 9 , wherein the additional substitution is a substitution of serine with leucine at position 428 (S428L). 8. The modified IgG of claim 7 , wherein the modified IgG having a feline IgG constant domain has a higher affinity for FcRn than an IgG having a wild-type feline IgG constant domain. 8. The modified IgG of claim 7 , wherein the modified IgG having a feline IgG constant domain has a higher half-life than an IgG having a wild-type feline IgG constant domain . The modified IgG of claim 7 , wherein the modified IgG comprises an Fc constant region having a CH2 or CH3 domain or a combination thereof . The modified IgG of claim 7 , wherein the feline IgG constant domain comprises the amino acid sequence set forth in SEQ ID NO:2. A pharmaceutical composition comprising the modified IgG of any one of claims 1 to 14 and a pharma- ceutically acceptable carrier. A fusion molecule comprising a modified IgG according to any one of claims 1 to 14 . An immunoglobulin molecule comprising a modified IgG according to any one of claims 1 to 14. A vector comprising a nucleic acid sequence encoding the amino acid sequence set forth in SEQ ID NO: 1 or 2. 20. An isolated cell comprising the vector of claim 18. 20. A method of producing a molecule, comprising providing a cell according to claim 19 and culturing said cell. Use of an IgG Fc region to increase the serum half-life of an IgG in a cat, said Fc region comprising a modified IgG according to any one of claims 1 to 14.