Decision and basis
Sanofi announced it will discontinue the MOBILIZE phase 3 trial evaluating riliprubart in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) who have been refractory to standard-of-care therapies. The decision follows an interim assessment conducted by an independent data monitoring committee, which determined that the trial is unlikely to generate adequate evidence of efficacy to justify continuation.
Safety findings
The independent committee did not detect any safety signals related to riliprubart during its interim analysis. That assessment, however, focused on the likelihood of establishing sufficient efficacy rather than identifying new safety concerns.
Implications for other studies
Sanofi said it will review the future of other ongoing riliprubart clinical programs, explicitly naming the VITALIZE phase 3 study in IVIg-treated CIDP patients as one under consideration. The company will determine whether those studies should proceed based on further analysis and consultation.
Transition and data review
The company will coordinate with investigators and trial site teams to wind down MOBILIZE and ensure appropriate transition of care for all participants currently enrolled. Sanofi also intends to perform a comprehensive analysis of the MOBILIZE dataset to guide potential future research directions and to contribute to the scientific understanding of CIDP.
Financial impact
Sanofi stated the termination of the MOBILIZE trial will not produce significant financial costs for the company and confirmed there is no change to its financial guidance for 2026.
About riliprubart and CIDP
Riliprubart is described as an IgG4 humanized monoclonal antibody that selectively inhibits activated C1s in the classical complement pathway, part of the innate immune system. The drug remains an investigational therapy; its safety and efficacy have not been evaluated or approved by any regulatory authority.
CIDP is characterized in Sanofi's announcement as a rare neurological disorder that leads to progressive weakness and sensory impairment in the arms and legs. The company notes that roughly 30% of people with CIDP do not respond to standard therapies, and among those who do, about 70% experience incomplete recovery.
This development will inform Sanofi's clinical strategy for riliprubart while the company balances patient care responsibilities, further data evaluation, and the status of related trials.