Long-Term Data from Study of Evobrutinib to Treat RMS Shows Low Relapse Rates and Stable Disability Scores
New results from an ongoing phase II open-label extension (OLE) trial (NCT02975349) presented at the 2023 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC) reported low relapse rates and no increase in disability associated with long-term treatment of relapsing multiple sclerosis (RMS) with evobrutinib (Merck KGaA, Darmstadt, Germany). Evobrutinib is a Bruton tyrosine kinase inhibitor under investigation as a potential treatment for RMS.
In the initial 48-week double-blind period (DBP) of the randomized, double-blind placebo-controlled trial, participants diagnosed with RMS (n=267) were assigned to 1 of 3 groups: group 1 received placebo before switching to evobrutinib once daily after week 24; group 2 received evobrutinib 25 mg once daily, 75 mg once daily, or 75 mg twice daily; and group 3 received open-label dimethyl fumarate 120 mg twice daily for the first week followed by 240 mg twice daily thereafter. Participants then had the option to enter the OLE during which they received evobrutinib 75 mg once daily before switching to evobrutinib 75 mg twice daily. In all, 128 participants completed ≥ 144 weeks of the ongoing OLE.
Annualized relapse rates (ARR) remained consistent between the DPB and the OLE periods, ranging from 0.11 (95% CI, 0.04-0.25) for the evobrutinib 75 mg twice daily group to 0.20 (95% CI, 0.14-0.28) in the OLE period for those treated with evobrutinib 75 mg once daily to 0.11 (95% CI, 0.07-0.15) in the OLE period for those treated with evobrutinib 75 mg twice daily. Additionally, a low change in Expanded Disability Status Scale (EDSS) scores was observed across all functional system scores (FSS) (pyramidal: –0.02 [0.04]; cerebellar: 0.09 [0.05]; brain stem: 0.00 [0.05]; sensory: –0.02 [0.05]; bowel and bladder: –0.02 [0.04]; visual function: –0.02 [0.05]; cerebral functions: –0.02 [0.04]).
Researchers who are part of this international study represent a variety of institutions, including the University of Colorado, the University of Texas Health Science Center at Houston, the University of Gottingen, Montreal Neurological Institute, Merck KGaA, and the Multiple Sclerosis Center of Catalonia.