European EMA's Positive Recommendation

The EMA's Committee for Medicinal Products for Human Use (CHMP) issued a positive recommendation on April 23, 2026, for Sanofi's multiple sclerosis treatment, Cenrifki (tolebrutinib). This decision follows the FDA's rejection in December of last year due to concerns about severe drug-induced liver injury (DILI), drawing significant industry attention. The CHMP recommended approval with strict liver monitoring, considering the benefit-risk balance for patients. This recommendation paves the way for final marketing authorization from the European Commission (EC) within a few months, potentially offsetting the setback in the U.S. market.

Significance of the HERCULES Phase 3 Data

The HERCULES Phase 3 trial, which served as the basis for this recommendation, involved patients with non-relapsing secondary progressive multiple sclerosis (nrSPMS). The Cenrifki arm demonstrated a 31% reduction in the risk of confirmed disability progression (CDP) compared to the placebo arm (hazard ratio of 0.69, p=0.003). The clinical results showed that only 22.6% of patients in the Cenrifki arm experienced disability progression, compared to 30.7% in the placebo arm, demonstrating a significant therapeutic effect. This data is scientifically valuable as it provides a new alternative that crosses the blood-brain barrier (BBB) for patients who previously had no treatment options.

Different Regulatory Judgments from the U.S. FDA

The differing regulatory approaches in Europe and the U.S. highlight the different perspectives on risk management for Bruton's tyrosine kinase (BTK) inhibitor-based therapies. The FDA determined that the potential risk of liver toxicity outweighed the benefits for patients and rejected the application in December 2025. In contrast, the EMA assessed that the benefits of treatment could be maximized while managing DILI adverse effects through a strict monitoring program. For Sanofi, this has added complexity in meeting the different guidelines of regulatory agencies in each region, but the European approval precedent could be leveraged to encourage a re-examination in the U.S.

Multiple Sclerosis Market Landscape and Competitive Dynamics

The global multiple sclerosis treatment market is estimated at approximately $29 billion to $34.8 billion in 2025, and the European market is also around $7.95 billion annually. The market is currently dominated by existing blockbuster drugs such as Roche's Ocrevus (ocrelizumab) and Novartis' Mayzent (siponimod). Sanofi acquired global rights to Cenrifki through the acquisition of Principia Biopharma for $3.68 billion in 2020, making entry into the European market crucial. With its differentiated small-molecule BTK inhibition mechanism, Cenrifki is expected to rapidly capture the nrSPMS patient population upon launch.

Future Prospects and Investor Perspective

Upon final approval from the European Commission, Sanofi plans to immediately initiate commercialization procedures and begin generating revenue in Europe. Investors are analyzing whether early revenue growth in Europe can offset the financial impact of the delayed approval in the U.S. market. At the same time, how Sanofi will supplement additional long-term safety data to address the FDA's concerns will be a key variable in future stock performance. Due to regulatory risks and the progress of competing products, short-term earnings volatility may exist, so it is necessary to maintain a wait-and-see approach and monitor the situation.