Sanofi scraps $11.6B Bioverativ drug trial after CIDP treatment failure

Sanofi has halted a major clinical trial for riliprubart, marking a significant setback for its rare disease portfolio. The decision follows an interim analysis showing the drug failed to treat CIDP effectively. The move raises questions about the broader success of Sanofi’s $11.6bn Bioverativ acquisition. Sanofi acquired Bioverativ in 2018 for $11.6bn, aiming to strengthen its rare disease pipeline. The company recently abandoned the Phase 3 MOBILIZE study of riliprubart, a C1s inhibitor designed to block the classical pathway of the human complement system. The trial involved 140 refractory CIDP patients across 134 global sites.

The drug’s failure has prompted Sanofi to review other ongoing studies of riliprubart. However, not all Bioverativ assets have underperformed. Altuviiio, approved in 2023 for haemophilia A, has shown strong commercial success, achieving Q1 2026 sales of around €325 million. Another C1s inhibitor from the same acquisition, Enjaymo, gained approval in 2022 before being sold to Recordati for $825 million. The abandonment of riliprubart puts pressure on the remaining Bioverativ pipeline to justify the acquisition’s cost. Altuviiio’s strong sales offer some validation, but doubts persist about the long-term value of the $11.6bn deal. Sanofi continues to assess the future of its other riliprubart studies.