Tolebrutinib Treatment Lowered Disease Activity of Relapsing Multiple Sclerosis  

In a phase 2b study, participants with relapsing multiple sclerosis (RMS) treated with tolebrutinib (SAR442168; Sanofi, Bridgewater, NJ) had reduced MS disease activity measured by MRI. Participants received 5, 15, 30, or 60 mg/day tolebrutinib for 14 weeks and then 60 mg/day for the following 34 weeks. All experienced low annualized relapse rate (ARR) of 0.17 (95% CI: 0.10, 0.29) and 89.5% were free of relapses during this period. The average Expanded Disability Status Scale (EDSS) scores across treatment groups ranged from 2.18 to 2.65 at baseline and remained stable through week 48. For the those who received a 60 mg dose for all 48 weeks had a mean (SD) EDSS score of 2.65 (1.22) at baseline and 2.45 (1.31) at week 48.

At week 48 the average number of new gadolinium (Gd)-enhancing lesions/scan remained low (<0.4) in those who had continuous dosing with 60 mg tolebrutinib. Participants who switched from a lower dose to 60 mg at week 15 also had a reduction in Gd-enhancing lesions, approaching values observed in those with continuous dosing at 60 mg treatment arm.
 
Through week 48,  98% (122/125) of participants continued treatment with tolebrutinib. 

“Results showed favorable safety and efficacy for tolebrutinib, and nearly all patients remained enrolled at the 1-year mark of the long-term extension study,” says Anthony Traboulsee, MD, professor and research chair, MS Society of Canada at University of British Columbia and phase 2b Extension Study Investigator. "Evaluating the impact BTK inhibitors can have on preventing disability accumulation is critical to addressing the needs of people living with MS. These long-term outcomes of tolebrutinib reinforce its potential as a new treatment option for MS patients."

The most frequent adverse reactions were headache (10%), COVID-19 (9%), upper respiratory tract infection (8%), and nasopharyngitis (7%). These data are being presented as ePosters at the 37th Congress of the European Committee for Treatment and Research in MS (ECTRIMS) on October 13 to 15, 2021.