Sanofi Riliprubart receives orphan drug designation in Japan for chronic inflammatory demyelinating polyneuropathy

The MHLW grants orphan drug designation to medicines that address rare medical diseases or conditions with unmet medical needs. There are currently approximately 4,000 people diagnosed with CIDP in Japan.

Erik Wallstroem, MD, PhD, Global Head of Neurology Development, Sanofi said, “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.”

Long-term, 76-week sustained efficacy and safety data from riliprubart’s phase 2 study were presented at the Peripheral Nerve Society meeting in Edinburgh, UK on May 17-20, 2025. Findings suggest a potential sustained long-term benefit provided by riliprubart across a broad spectrum of participants with CIDP.

Riliprubart is currently being tested in two separate phase 3 studies: MOBILIZE in patients refractory to standard of care (clinical study identifier: NCT06290128) and VITALIZE in IVIg-treated patients (clinical study identifier: NCT06290141).

SAR445088 (riliprubart) is an IgG4 humanized monoclonal antibody that selectively inhibits activated C1s in the classical complement pathway of the innate immune system. By blocking C1s, riliprubart has the potential to inhibit key inflammatory mechanisms that drive demyelination and axonal damage in CIDP. Riliprubart is currently under clinical investigation, and its safety and efficacy have not been evaluated by any regulatory authority.