Monoclonal humanized monovalent antibody blocking therapy for anti-NMDA receptor encephalitis

A Atsuo Kanno T Takuya Kito M Masashi Maeda S Shanni Yamaki Y Yasushi Amano T Takuya Shimomura M Margarita Anisimova N Naomi Kanazawa K Koichiro Suzuki (Division of Biochemistry, Faculty of Pharmacy and Graduate School of Pharmaceutical Sciences, Keio University) A Amir Razai T Takuma Mihara K Kaori Kubo T Takeshi Shimada K Koji Nakamura N Naoko Nomura Y Yuji Kondo A Akira Okimoto A Azusa Sugiyama D Deborah Park I Ivar Stein S Samuel Petshow V Valentin Vandendoren S Sanela Bilic R Roghiye Kazimi V Vallari Eastman S Scott J. Snipas M Mathew Mitchell M Mari Maurer M Marty Jefson J Jay Lichter D Daisuke Yamajuku H Hiroki Shirai M Megumi Adachi D Daniel J. Hoeppner S Satoshi Kubo K Karen Zito (Center for Neuroscience, University of California) T Takahiro Iizuka P Peter Flynn M Mitsuyuki Matsumoto

Abstract

Abstract Anti-NMDA receptor (NMDAR) encephalitis is a devastating disease with severe psychiatric and neurological symptoms believed to be caused by pathogenic autoantibodies that bind to the N-terminal domain (NTD) of the NMDAR GluN1 subunit (GluN1-NTD) crosslinking adjacent NMDARs and driving their internalization. Here we describe ART5803, a humanized monovalent antibody, as a potential therapy for anti-NMDAR encephalitis. ART5803 binds with a high affinity (KD = 0.69 nM) to GluN1-NTD without affecting NMDAR activity or inducing internalization. ART5803 blocks NMDAR internalization induced by patients’ pathogenic autoantibodies, and restores NMDAR function. A marmoset animal model was developed using sustained intracerebroventricular (ICV) administration of a human pathogenic autoantibody to evoke behavioral and motor abnormalities. ART5803 ICV infusion or peripheral injections rapidly reversed these abnormalities. These data, together with the pharmacokinetic profile in cynomolgus monkeys, indicate a therapeutic potential for intravenous (IV)-administered ART5803 as a fast-acting and efficacious option for anti-NMDAR encephalitis.

Article Details

Volume / Issue Vol. 16, Issue 1
Published June 17, 2025
ISSN 2041-1723
Publisher Nature Portfolio

Journal Info

Nature Communications

Nature Portfolio

ISSN: 2041-1723 Open Access Life Sciences

Authors (39)

A

Atsuo Kanno

T

Takuya Kito

M

Masashi Maeda

S

Shanni Yamaki

Y

Yasushi Amano

T

Takuya Shimomura

M

Margarita Anisimova

N

Naomi Kanazawa

K

Koichiro Suzuki

Division of Biochemistry, Faculty of Pharmacy and Graduate School of Pharmaceutical Sciences, Keio University

A

Amir Razai

T

Takuma Mihara

K

Kaori Kubo

T

Takeshi Shimada

K

Koji Nakamura

N

Naoko Nomura

Y

Yuji Kondo

A

Akira Okimoto

A

Azusa Sugiyama

D

Deborah Park

I

Ivar Stein

S

Samuel Petshow

V

Valentin Vandendoren

S

Sanela Bilic

R

Roghiye Kazimi

V

Vallari Eastman

S

Scott J. Snipas

M

Mathew Mitchell

M

Mari Maurer

M

Marty Jefson

J

Jay Lichter

D

Daisuke Yamajuku

H

Hiroki Shirai

M

Megumi Adachi

D

Daniel J. Hoeppner

S

Satoshi Kubo

K

Karen Zito

Center for Neuroscience, University of California

T

Takahiro Iizuka

P

Peter Flynn

M

Mitsuyuki Matsumoto