PARIS, France, June 10, 2026
Sanofi announced that it will discontinue the Phase 3 MOBILIZE study evaluating riliprubart in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) who are refractory to standard-of-care treatments. The decision follows a planned interim analysis conducted by an independent data monitoring committee, which concluded that the study was unlikely to demonstrate sufficient efficacy. No safety concerns related to riliprubart were identified during the review. The company stated that it remains committed to supporting affected patients and investigators throughout the study wind-down process.
Interim Analysis Indicates Low Probability of Meeting Efficacy Objectives
The MOBILIZE Phase 3 trial was designed to evaluate riliprubart in CIDP patients who had not responded adequately to currently available treatment options. Following review of interim clinical data, the independent monitoring committee determined that the study was unlikely to achieve its efficacy goals, prompting Sanofi to terminate the trial. While the decision represents a setback for the program, the findings provide important information regarding the therapeutic potential of complement pathway inhibition in treatment-resistant CIDP patients.
No New Safety Signals Identified for Riliprubart
Despite the lack of efficacy observed in the study, Sanofi reported that no safety signals associated with riliprubart were detected during the interim analysis. The investigational therapy, a humanized monoclonal antibody targeting activated C1s in the classical complement pathway, was developed to inhibit inflammatory mechanisms believed to contribute to nerve damage and demyelination in CIDP. The company will conduct a comprehensive review of the study data to better understand the results and guide future scientific research in the disease area.
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Future Development Plans Under Evaluation
Sanofi noted that the continuation of other ongoing riliprubart clinical studies, including the Phase 3 VITALIZE trial in intravenous immunoglobulin (IVIg)-treated CIDP patients, will be evaluated in light of the MOBILIZE findings. The company emphasized that the study termination is not expected to have a significant financial impact and does not alter its financial guidance for 2026. Sanofi plans to share insights from the completed analysis to contribute to the broader scientific understanding of CIDP and potential future treatment approaches.
Source: Sanofi press release
