French healthcare company Sanofi S.A. (Euronext Paris:SAN) (Nasdaq:SNY) said on Wednesday that the US Food and Drug Administration (FDA) has granted orphan drug designation for riliprubart (SAR445088) in the treatment of antibody-mediated rejection in solid organ transplantation.

This designation highlights a significant unmet need in transplant medicine, where no FDA-approved therapies currently exist for this condition.

Riliprubart is a humanised monoclonal antibody that selectively inhibits activated C1s in the classical complement pathway of the innate immune system. It is currently being evaluated in a phase 2 study for the prevention and treatment of antibody-mediated rejection in kidney transplant recipients, with separate cohorts for at-risk and actively affected patients.

In addition to its transplant indication, riliprubart has also received orphan drug designation in the United States and European Union for chronic inflammatory demyelinating polyneuropathy (CIPD). Sanofi is advancing two phase 3 trials for this rare neurological disorder, targeting patients refractory to standard of care and those treated with intravenous immunoglobulin.

These developments underscore Sanofi's broader strategy to advance riliprubart across multiple immune-mediated conditions with high unmet needs.