公开(公告)号：US09688756B2

公开(公告)日：2017-06-27

申请号：US14367183

申请日：2012-12-17

Applicant: Amgen Inc.

Inventor： Jeonghoon Sun ,  Seog Joon Han ,  Susie M Harris ,  Randal R Ketchem ,  Ji Lu ,  Mark L Michaels ,  Marc W Retter ,  Mei-Mei Tsai

IPC: C07K16/00 ,  C07K16/28 ,  G01N33/68

CPC classification number: C07K16/28 ,  C07K16/00 ,  C07K2317/30 ,  C07K2317/524 ,  C07K2317/526 ,  C07K2317/72 ,  C07K2317/90 ,  C07K2317/94 ,  G01N33/6857 ,  G01N2333/705

Abstract: Described herein are variant Fc-fragments that contain an insertion within or adjacent to a loop that bind to the neonatal Fc receptor (FcRn) with higher affinity and/or higher binding activity at pH 5-6 and approximately the same or lower affinity at a physiologic pH as compared to a control Fc-fragment, that is, little or no binding activity at a physiologic pH. Also described are variant Fc-polypeptides that comprise these variant Fc-fragments. Further described are methods of making and identifying such Fc-fragments and methods for making and using such Fc-polypeptides.