Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody

Recent development of amyloid-β (Aβ)-targeted immunotherapies for Alzheimer’s disease (AD) have highlighted the need for accurate diagnostic methods. Antibody-based positron emission tomography (PET) ligands are well suited for this purpose as they can be directed toward the same target as the thera...

Full description

Saved in:
Bibliographic Details
Main Authors: Eva Schlein, Ken G. Andersson, Tiffany Dallas, Stina Syvänen, Dag Sehlin
Format: Article
Language:English
Published: Taylor & Francis Group 2024-12-01
Series:mAbs
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/19420862.2024.2339337
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832576583614857216
author Eva Schlein
Ken G. Andersson
Tiffany Dallas
Stina Syvänen
Dag Sehlin
author_facet Eva Schlein
Ken G. Andersson
Tiffany Dallas
Stina Syvänen
Dag Sehlin
author_sort Eva Schlein
collection DOAJ
description Recent development of amyloid-β (Aβ)-targeted immunotherapies for Alzheimer’s disease (AD) have highlighted the need for accurate diagnostic methods. Antibody-based positron emission tomography (PET) ligands are well suited for this purpose as they can be directed toward the same target as the therapeutic antibody. Bispecific, brain-penetrating antibodies can achieve sufficient brain concentrations, but their slow blood clearance remains a challenge, since it prolongs the time required to achieve a target-specific PET signal. Here, two antibodies were designed based on the Aβ antibody bapineuzumab (Bapi) – one monospecific IgG (Bapi) and one bispecific antibody with an antigen binding fragment (Fab) of the transferrin receptor (TfR) antibody 8D3 fused to one of the heavy chains (Bapi-Fab8D3) for active, TfR-mediated transport into the brain. A variant of each antibody was designed to harbor a mutation to the neonatal Fc receptor (FcRn) binding domain, to increase clearance. Blood and brain pharmacokinetics of radiolabeled antibodies were studied in wildtype (WT) and AD mice (AppNL-G-F). The FcRn mutation substantially reduced blood half-life of both Bapi and Bapi-Fab8D3. Bapi-Fab8D3 showed high brain uptake and the brain-to-blood ratio of its FcRn mutated form was significantly higher in AppNL-G-F mice than in WT mice 12 h after injection and increased further up to 168 h. Ex vivo autoradiography showed specific antibody retention in areas with abundant Aβ pathology. Taken together, these results suggest that reducing FcRn binding of a full-sized bispecific antibody increases the systemic elimination and could thereby drastically reduce the time from injection to in vivo imaging.
format Article
id doaj-art-e26e8d4cee664eda81a36e31dae1d509
institution Kabale University
issn 1942-0862
1942-0870
language English
publishDate 2024-12-01
publisher Taylor & Francis Group
record_format Article
series mAbs
spelling doaj-art-e26e8d4cee664eda81a36e31dae1d5092025-01-31T04:19:38ZengTaylor & Francis GroupmAbs1942-08621942-08702024-12-0116110.1080/19420862.2024.2339337Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibodyEva Schlein0Ken G. Andersson1Tiffany Dallas2Stina Syvänen3Dag Sehlin4Department of Public Health and Caring Sciences, Uppsala University, Uppsala, SwedenBiotechnology, BioArctic AB, Stockholm, SwedenDepartment of Public Health and Caring Sciences, Uppsala University, Uppsala, SwedenDepartment of Public Health and Caring Sciences, Uppsala University, Uppsala, SwedenDepartment of Public Health and Caring Sciences, Uppsala University, Uppsala, SwedenRecent development of amyloid-β (Aβ)-targeted immunotherapies for Alzheimer’s disease (AD) have highlighted the need for accurate diagnostic methods. Antibody-based positron emission tomography (PET) ligands are well suited for this purpose as they can be directed toward the same target as the therapeutic antibody. Bispecific, brain-penetrating antibodies can achieve sufficient brain concentrations, but their slow blood clearance remains a challenge, since it prolongs the time required to achieve a target-specific PET signal. Here, two antibodies were designed based on the Aβ antibody bapineuzumab (Bapi) – one monospecific IgG (Bapi) and one bispecific antibody with an antigen binding fragment (Fab) of the transferrin receptor (TfR) antibody 8D3 fused to one of the heavy chains (Bapi-Fab8D3) for active, TfR-mediated transport into the brain. A variant of each antibody was designed to harbor a mutation to the neonatal Fc receptor (FcRn) binding domain, to increase clearance. Blood and brain pharmacokinetics of radiolabeled antibodies were studied in wildtype (WT) and AD mice (AppNL-G-F). The FcRn mutation substantially reduced blood half-life of both Bapi and Bapi-Fab8D3. Bapi-Fab8D3 showed high brain uptake and the brain-to-blood ratio of its FcRn mutated form was significantly higher in AppNL-G-F mice than in WT mice 12 h after injection and increased further up to 168 h. Ex vivo autoradiography showed specific antibody retention in areas with abundant Aβ pathology. Taken together, these results suggest that reducing FcRn binding of a full-sized bispecific antibody increases the systemic elimination and could thereby drastically reduce the time from injection to in vivo imaging.https://www.tandfonline.com/doi/10.1080/19420862.2024.2339337Alzheimer’s disease (AD)amyloid-β (aβ)bispecific antibodyblood-brain barrier (BBB)neonatal Fc receptor (FcRn)receptor mediated transcytosis (RMT)
spellingShingle Eva Schlein
Ken G. Andersson
Tiffany Dallas
Stina Syvänen
Dag Sehlin
Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody
mAbs
Alzheimer’s disease (AD)
amyloid-β (aβ)
bispecific antibody
blood-brain barrier (BBB)
neonatal Fc receptor (FcRn)
receptor mediated transcytosis (RMT)
title Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody
title_full Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody
title_fullStr Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody
title_full_unstemmed Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody
title_short Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody
title_sort reducing neonatal fc receptor binding enhances clearance and brain to blood ratio of tfr delivered bispecific amyloid β antibody
topic Alzheimer’s disease (AD)
amyloid-β (aβ)
bispecific antibody
blood-brain barrier (BBB)
neonatal Fc receptor (FcRn)
receptor mediated transcytosis (RMT)
url https://www.tandfonline.com/doi/10.1080/19420862.2024.2339337
work_keys_str_mv AT evaschlein reducingneonatalfcreceptorbindingenhancesclearanceandbraintobloodratiooftfrdeliveredbispecificamyloidbantibody
AT kengandersson reducingneonatalfcreceptorbindingenhancesclearanceandbraintobloodratiooftfrdeliveredbispecificamyloidbantibody
AT tiffanydallas reducingneonatalfcreceptorbindingenhancesclearanceandbraintobloodratiooftfrdeliveredbispecificamyloidbantibody
AT stinasyvanen reducingneonatalfcreceptorbindingenhancesclearanceandbraintobloodratiooftfrdeliveredbispecificamyloidbantibody
AT dagsehlin reducingneonatalfcreceptorbindingenhancesclearanceandbraintobloodratiooftfrdeliveredbispecificamyloidbantibody