Sanofi SA (SNY) announced promising results from the HERCULES Phase 3 study evaluating tolebrutinib, a potential treatment for non-relapsing secondary progressive multiple sclerosis (nrSPMS). The study showed that tolebrutinib significantly delayed the time to onset of 6-month confirmed disability progression (CDP) by 31% compared to placebo. This statistically significant difference (p=0.0026) indicates a potential benefit for patients with nrSPMS.
Further analysis of the secondary endpoints revealed that the number of participants experiencing confirmed disability improvement was nearly double in the tolebrutinib group (10%) compared to the placebo group (5%). This finding reinforces the potential of tolebrutinib to slow disease progression and potentially improve functionality for patients.
While these results are encouraging, the study also observed a slight increase in some adverse events among patients treated with tolebrutinib. Liver enzyme elevations were seen in 4.1% of patients receiving tolebrutinib compared to 1.6% in the placebo group. This side effect is consistent with observations in other BTK inhibitors used to treat MS. Importantly, nearly all cases of liver enzyme elevations resolved without further medical intervention.
These latest findings build on previous results from the GEMINI 1 and 2 Phase 3 studies, which evaluated tolebrutinib in relapsing forms of MS. While those studies did not meet the primary endpoint of reducing annualized relapse rate (ARR), they revealed a substantial delay in time to onset of 6-month confirmed disability worsening (CDW). This observation aligns with the CDP data from the HERCULES study, suggesting tolebrutinib’s potential benefits across different forms of MS.
Preliminary analysis of the pooled safety data from GEMINI 1 and 2 showed generally balanced adverse event profiles between the tolebrutinib and Aubagio (teriflunomide) groups. Liver enzyme elevations were observed in 5.6% of patients receiving tolebrutinib and 6.3% of patients receiving Aubagio.
Sanofi plans to submit these findings to global regulatory authorities for review in the second half of 2024. The company is also currently conducting the PERSEUS Phase 3 study in primary progressive MS, with results expected in the second half of 2025. These studies represent significant steps forward in understanding tolebrutinib’s potential as a treatment option for various forms of MS.
Sanofi’s stock (SNY) was down 0.53% at $57.95 in premarket trading on Friday.
