Sanofi's BTK Inhibitor Cenrifki Approved in Europe as Treatment for Non-Relapsing Secondary Progressive Multiple Sclerosis
First Targeted Therapy for Disability Progression Approved in Europe
The European Medicines Agency (EMA) has granted final approval for Sanofi's BTK inhibitor Cenrifki (generic name: tolebrutinib) as a treatment for non-relapsing secondary progressive multiple sclerosis (nrSPMS). This marks the first disease-modifying therapy (DMT) in the nrSPMS field to be officially approved for slowing disability progression, addressing a significant unmet medical need. The approval provides a new treatment option for MS patients and strengthens Sanofi's portfolio in neurological disorders. The medical community across Europe has warmly welcomed the decision, with expectations that it will quickly translate into prescriptions.
Scientific Success of Phase 3 HERCULES Trial and Liver Toxicity Concerns
The European Commission's approval was based on positive data from the global Phase 3 HERCULES trial in nrSPMS patients. Tolebrutinib reduced the risk of confirmed disability progression (CDP) over six months by 31% compared to placebo, and the proportion of patients showing meaningful improvement in disability was nearly twice that of the placebo group. However, during the trial, more than 4% of patients experienced elevated liver enzyme levels (ALT) more than three times the normal range, and there were reports of severe drug-induced liver injury (DILI), including a fatality. European regulators considered these safety concerns and approved the drug with a conditional requirement for regular liver function monitoring.
FDA Denial and Divergent Regulatory Pathways
In contrast to the European approval, the U.S. Food and Drug Administration (FDA) issued a Complete Response Letter (CRL) in December last year, rejecting tolebrutinib and taking a more cautious stance. The FDA determined that the risk of serious liver toxicity outweighed the therapeutic benefits for patients. As a result, Sanofi lost the opportunity for early market entry in the U.S., the largest pharmaceutical market, and now faces the challenge of revising its global commercialization strategy. The divergent regulatory decisions between the two major agencies have drawn attention in the biopharma industry, particularly regarding regional differences in managing drug safety risks.
Pricing Negotiations and Market Access Challenges in Europe
Following the formal approval, Sanofi's most immediate challenge is to swiftly complete pricing negotiations and reimbursement listings with health authorities across European countries. European nations are known for conducting rigorous cost-effectiveness evaluations, and they are expected to closely assess the cost-benefit ratio of the drug, including the expenses associated with safety monitoring. The mandatory regular blood tests required for liver toxicity monitoring may lead to prescribing hesitancy or reimbursement cuts in clinical practice. At this critical juncture, Sanofi must proactively establish a robust safety management system in collaboration with local healthcare institutions to maximize drug accessibility.
Sanofi's European approval of tolebrutinib has secured a unique position in the global multiple sclerosis market, but the FDA's denial in the U.S. has led to a downward revision of its market value. Despite demonstrating a 31% reduction in the risk of confirmed disability progression (CDP) over six months in the Phase 3 HERCULES trial compared to placebo, the serious liver toxicity observed in 4.1% of patients will act as a constraint on broader prescribing. To outperform existing competitors such as Novartis' Siponimod in the MS treatment market, projected to reach approximately $66.8 billion by 2035, Sanofi must prioritize rapid pricing negotiations in Europe and establish a strict safety monitoring system. In the medium to long term, the European Commission's approval decision is expected to serve as a significant benchmark for the clinical design and regulatory approval criteria of subsequent BTK inhibitors such as Roche's fenebrutinib.
Source: EMA (ema)