Sanofi SA’s experimental drug, tolebrutinib, has shown promising results in treating multiple sclerosis (MS). Data from the HERCULES phase 3 study revealed that tolebrutinib successfully met the primary endpoint, delaying the onset of confirmed disability progression (CDP) in patients with non-relapsing secondary progressive multiple sclerosis (nrSPMS). This form of MS is characterized by a gradual worsening of disability without experiencing relapses.
The HERCULES study defined nrSPMS as patients with an SPMS diagnosis, an expanded disability status scale (EDSS) score between 3.0 and 6.5, no clinical relapses in the past 24 months, and documented evidence of disability accumulation in the previous 12 months.
Preliminary analysis of liver safety data from the HERCULES study aligned with previous findings from tolebrutinib studies. However, results from the GEMINI 1 and 2 phase 3 studies, focusing on relapsing forms of MS, did not meet the primary endpoint of reducing annualized relapse rate (ARR) compared to teriflunomide. Nevertheless, analysis of pooled 6-month confirmed disability worsening (CDW) data revealed a considerable delay in the time to onset of disability worsening, supporting the CDP data observed in HERCULES.
Sanofi is currently conducting the PERSEUS phase 3 study in primary progressive multiple sclerosis (PPMS), evaluating the time to onset of CDP. Results from this study are expected in 2025.
“Tolebrutinib represents an unprecedented breakthrough as a potential first-in-disease treatment option with clinically meaningful benefit in disability accumulation,” said Houman Ashrafian, Sanofi’s head of research & development.
Despite the promising results, tolebrutinib’s future remains uncertain. In 2022, the FDA placed Sanofi’s Phase 3 studies of tolebrutinib in MS and myasthenia gravis on partial clinical hold due to a limited number of drug-induced liver injury cases identified in Phase 3 studies.
While tolebrutinib appears to be a potentially valuable treatment option, concerns regarding potential liver damage and its overall effectiveness persist. These concerns cast uncertainty over the drug’s revenue prospects. According to Reuters, investors remain cautious, despite analysts from Jefferies predicting a potential $1 billion to $2 billion opportunity for the drug.
Sanofi’s stock (SNY) saw a 2.84% increase during the premarket session on Tuesday, reaching $57.86.
