Tolebrutinib in SPMS

31% delay in time to onset of confirmed disability progression in non-relapsing Secondary Progressive Multiple Sclerosis (SPMS)

• Phase 3 study data presented at ECTRIMS show that tolebrutinib, a brain-penetrant BTK inhibitor, addresses disability accumulation that occurs independently from relapse activity
• Global regulatory submissions will begin in H2 2024

20 September, 2024: Positive results from the HERCULES phase 3 study in people with non-relapsing secondary progressive multiple sclerosis (nrSPMS) demonstrated that tolebrutinib delayed the time to onset of 6-month confirmed disability progression (CDP) by 31% compared to placebo (HR 0.69; 95% CI 0.55-0.88; p=0.0026). Further analysis of secondary endpoints demonstrated that the number of participants who experienced confirmed disability improvement increased by nearly two-fold, 10% with tolebrutinib compared to 5% with placebo (HR 1.88; 95% CI 1.10 to 3.21; nominal p=0.021). These results were presented on 20th September as a late-breaking presentation at the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) 2024 conference in Copenhagen, Denmark.

“Secondary progressive multiple sclerosis is characterized by insidious worsening of disability over time, independent of relapses, and represents a critical unmet need because we don’t have effective treatments. The results of HERCULES show clearly that tolebrutinib delayed disability progression in people with nrSPMS – and some people even improved disability – by uniquely targeting the biological processes driving disease progression in the brain.” Dr. Fox is a paid advisor to Sanofi for the HERCULES trial.

Robert Fox, MD, Vice Chair of Research at Cleveland Clinic’s Neurological Institute, Cleveland, Ohio and Chair of the HERCULES Global Steering Committee

Based on preliminary analysis of the HERCULES study, there was a slight increase in tolebrutinib-treated patients of some adverse events. Liver enzyme elevations (>3xULN) were observed in 4.1% of participants receiving tolebrutinib compared with 1.6% in the placebo group, a side effect also reported with other BTK inhibitors in MS. A small (0.5%) proportion of participants in the tolebrutinib group experienced peak ALT increases of >20xULN, all occurring within the first 90 days of treatment. All but one case of liver enzyme elevations resolved without further medical intervention. Prior to the implementation of the revised study protocol with more stringent monitoring, one participant in the tolebrutinib arm received a liver transplant and died due to post-operative complications. To date, the implementation of more frequent monitoring has mitigated such serious liver sequelae. Other deaths in the trial were assessed as unrelated to treatment by investigator; deaths were even across the placebo and tolebrutinib arms at 0.3%.

“With no treatment options currently available for the broad population of patients with secondary progressive multiple sclerosis, tolebrutinib has demonstrated its ability to delay disability by targeting underlying drivers of the disease. We look forward to discussing these results with healthcare authorities and are eager to see the results of tolebrutinib in primary progressive MS when they become available next year. We extend our deepest appreciation to the study participants, their families, and the healthcare professionals involved in these trials.
Houman Ashrafian, MD, PhD, Head of Research & Development, Sanofi

The GEMINI 1 and 2 phase 3 study results of tolebrutinib compared to Aubagio (teriflunomide), a standard-of-care treatment, in participants with relapsing multiple sclerosis (RMS) were also presented as a late-breaking presentation at ECTRIMS. Both studies did not meet their primary endpoints of statistically significant improvement in annualised relapse rates (ARR) compared to Aubagio. However, in the key secondary endpoint, a pooled analysis of data from GEMINI 1 and 2, tolebrutinib delayed the time to onset of 6-month confirmed disability worsening (CDW) by 29% (HR 0.71; 95% CI: 0.53-0.95; nominal p=0.023). The results of the 29% delay in CDW endpoint in participants with RMS are in line with the 31% delay in CDP observed in participants with nrSPMS. The significant impact of tolebrutinib on disability accumulation versus Aubagio, in the absence of a statistically superior impact on relapses, suggests that tolebrutinib may address smoldering neuroinflammation, which manifests as progression independent of relapses.

Furthermore, results showed historically low ARR in the Aubagio arm in both GEMINI 1 and 2, and no difference was observed between Aubagio and tolebrutinib in a pooled analysis. These relapse rates amount to approximately 1 relapse every 8 years.

In preliminary analysis of the GEMINI 1 and 2 pooled safety data, adverse events observed between the tolebrutinib and Aubagio arms were generally balanced. Liver enzyme elevations (>3x ULN) were observed in 5.6% of participants receiving tolebrutinib compared with 6.3% of participants receiving Aubagio, a side effect reported with other BTK inhibitors in MS and resolved without further medical intervention. A small (0.5%) proportion of participants in the tolebrutinib group experienced peak ALT increases of >20xULN, all occurring within the first 90 days of treatment. Deaths were balanced across the Aubagio and tolebrutinib arms, at 0.2% and 0.1% respectively, and were assessed as unrelated to treatment by investigator.

*For participants receiving tolebrutinib

Study results will form the basis for future discussions with global regulatory authorities with submissions starting in H2 2024. Tolebrutinib is currently under clinical investigation, and its safety and efficacy have not been evaluated by any regulatory authority. 

The PERSEUS phase 3 study in primary progressive MS is currently ongoing with study results anticipated in H2 2025.