Sanofi Stops MOBILIZE Phase 3 Trial of Riliprubart in Refractory CIDP After Interim Futility Analysis

An independent data monitoring committee's interim futility finding has halted Sanofi's MOBILIZE phase 3 study of riliprubart in refractory chronic inflammatory demyelinating polyneuropathy (CIDP), triggering clinical supply wind-down obligations and patient transition protocols across all enrolled sites.

The DMC determined that MOBILIZE (NCT06290128) was unlikely to demonstrate sufficient efficacy in patients refractory to standard-of-care treatment. No safety signals were identified. For clinical operations and QA leads managing investigational product at active sites, the immediate priority shifts to controlled decommissioning: reconciling riliprubart inventory, closing out batch records, and executing patient transition plans in line with GCP obligations and sponsor-defined protocols.

Riliprubart is an IgG4 humanized monoclonal antibody that selectively inhibits activated C1s in the classical complement pathway. The mechanism was designed to interrupt the inflammatory cascade driving demyelination and axonal damage in CIDP. The MOBILIZE failure does not, on its own, invalidate the complement inhibition hypothesis; the enrolled population, patients refractory to standard therapies, represents a distinct clinical and immunological profile from IVIg-treated patients enrolled in the parallel VITALIZE phase 3 study (NCT06290141), whose continuation Sanofi says will now be evaluated in light of these data.

The distinction between the two study populations carries direct relevance for manufacturing and supply planning. MOBILIZE's termination removes one demand stream for riliprubart clinical supply, but VITALIZE's fate remains open. Supply chain leads supporting ongoing riliprubart production should anticipate a formal continuation decision from Sanofi before adjusting batch scheduling or clinical packaging commitments tied to VITALIZE.

Sanofi confirmed the termination carries no significant financial cost and leaves 2026 guidance unchanged. A full analysis of MOBILIZE data is planned to inform future research directions and contribute to the broader scientific understanding of CIDP, a condition where approximately 30% of patients do not respond to standard therapies and fewer than one-third sustain remission without continued treatment.

The VITALIZE continuation decision will serve as the next measurable checkpoint for teams with active riliprubart manufacturing or clinical supply commitments.

Source: Sanofi via GlobeNewswire, June 10, 2026.