Evobrutinib Treatment Reduced Annualized Relapse Rate Sustained in Open-Label Extension Study

Results from a phase 2 open-label extension (OLE) study (NCT02975349) presented and the European Academy of Neurology (EAN) 2020 Virtual Congress showed treatment with evobruitnib (Merck KGaA, Darmstadt, Germany) reduced the annualized relapse rate (ARR) for people with multiple sclerosis (MS) significantly and sustainably. Of 267 participants in the open label extension, 213 (80%) completed 108 weeks of treatment (48 weeks in the main study and 60 weeks in the OLE). Statistically significant reductions in the cumulative number of T1 gadolinium-enhancing (Gd+) lesions with evobrutinib treatment compared with placebo were first seen at 24 weeks. The reduction in ARR was maintained over the open-label extension.

Participants who received evobrutinib in the double-blind phase had an ARR of 0.11 (95% CI 0.04-0.25) at week 48, and 0.12 (0.06-0.22) for the 108-week period. At week 48, all patients could enter the OLE, which assessed the long-term efficacy and safety of the drug.The therapy was generally well-tolerated, with the safety profile maintained during the OLE, including no increase in infections and no new safety signals identified. 

Evobrutinib is an inhibitor of Bruton tyrosine kinase (BTK) being investigated for the treatment of MS.

“These data demonstrate evobrutinib has a sustained and high impact on annualized relapse rate over 108 weeks,” said Luciano Rossetti, head of global research and development, Merck KGaA. “Greatest efficacy was clearly associated with BTK occupancy, and this further validates our choice of dose for the phase 3 program. We are also encouraged by evobrutinib’s breadth of consistent safety data, including no increase of serious infections in more than 1,200 patients up to 2 years.”