
Sanofi’s antibody riliprubart has received orphan drug designation (ODD) from Japan’s Ministry of Health, Labour and Welfare (MHLW) for its potential to treat chronic inflammatory demyelinating polyneuropathy (CIDP), a rare neurological disorder.
Riliprubart is a humanised immunoglobulin G4 (IgG4) monoclonal antibody inhibiting activated C1s within the classical complement pathway.
In Japan alone, around 4,000 individuals have a CIDP diagnosis.
Sanofi neurology development global head Erik Wallstroem stated: “The orphan drug designation of riliprubart for people living with CIDP in Japan underscores our commitment to applying our deep understanding of the immune system to address rare neurological disorders with significant unmet medical needs.
“While CIDP therapies exist, many individuals continue to experience debilitating symptoms, including pain, fatigue and weakness. Our ongoing development of riliprubart reflects our dedication to challenging the status quo in neurology with the goal of improving people’s lives.”
A Phase II trial data indicates that riliprubart may offer sustained safety and efficacy over a 76-week period for a wide range of CIDP patients.

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By GlobalDataCIDP leads to progressive weakness as well as sensory loss in the legs and arms.
Early diagnosis is crucial, as it enables timely intervention that can help prevent long-term disability. Unfortunately, even with available treatments, many individuals continue to experience persistent symptoms such as weakness, numbness and fatigue, which can result in prolonged morbidity and a reduced quality of life.
The antibody is currently undergoing further investigation in two separate Phase III studies, MOBILIZE in subjects refractory to standard of care and VITALIZE in intravenous immunoglobulin (IVIg)-treated patients.
In June 2025, the Department of Health – Abu Dhabi (DoH) and Sanofi signed a memorandum of understanding aimed at enhancing vaccine development.
This collaboration will use local health technology ecosystems and research facilities, with an emphasis on improving regulatory processes, advancing manufacturing facilities and fostering knowledge sharing between regional and international experts.