A plain language summary of what clinical studies can tell us about the safety of evobrutinib - a potential treatment for multiple sclerosis.

WHAT IS THIS SUMMARY ABOUT?: This summary explains the findings from a recent investigation that combined the results of over 1000 people from three clinical studies to understand the safety of evobrutinib. Evobrutinib is an oral medication (taken by mouth), being researched as a potential treatment for multiple sclerosis (MS). This medication was also investigated in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Over 1000 people have taken evobrutinib as part of three separate phase 2 clinical studies. These studies looked at how much of the drug should be taken, how safe the drug is, and how well it might work for treating a certain medical condition. WHAT WERE THE RESULTS?: Evobrutinib was well-tolerated by participants in all three studies. The number of side effects reported by participants taking the medication was very similar to those reported by participants taking the placebo (a 'dummy' treatment without a real drug). The most common side effects in clinical studies were urinary tract infections, headache, swelling of the nose and throat, diarrhoea and blood markers of potential liver damage (these returned to normal once the treatment was stopped). WHAT DO THE RESULTS MEAN?: The safety data from all three clinical studies are encouraging and can be used to inform further research into using evobrutinib in MS. Clinical Trial Registration: NCT02975349 (multiple sclerosis), NCT03233230 (rheumatoid arthritis), NCT02975336 (systemic lupus erythematosus) (ClinicalTrials.gov).

Characterisation of the safety profile of evobrutinib in over 1000 patients from phase II clinical trials in multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus: an integrated safety analysis.

OBJECTIVE: Analyse the integrated safety profile of evobrutinib, a Bruton's tyrosine kinase inhibitor (BTKi), using pooled data from multiple sclerosis (MS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) trials. METHODS: Phase II, randomised, double-blind, placebo-controlled trial data were analysed (N=1083; MS: n=213, 48 weeks (W); RA: n=390, 12W; SLE: n=480, 52W). The analysis included all patients who received ≥1 dose of evobrutinib (25 mg or 75 mg once daily, or 50 mg or 75 mgtwice daily) or placebo. Descriptive statistics and exposure-adjusted incidence rates (EAIR) were used to report treatment-emergent adverse events (TEAEs). RESULTS: Data from 1083 patients were pooled: evobrutinib, n=861; placebo, n=271 (sum >1083 due to MS trial design: n=49 received both placebo (W0-24) and evobrutinib 25 mg (W25-48)); median follow-up time (pt-years): evobrutinib, 0.501; placebo, 0.463. Across indications, the proportion of patients with TEAEs and the EAIR were similar for evobrutinib and placebo (66.2% (247.6 events/100 pt-years) vs 62.4% (261.4 events/100 pt-years)). By indication, the EAIR (events/100 pt-years) of TEAEs for evobrutinib versus placebo were: MS: 119.7 vs 148.3; RA: 331.8 vs 306.8; SLE: 343.0 vs 302.1. Two fatal events occurred (in SLE). The serious infections EAIR was 2.7 and 2.1 events/100 pt-years for evobrutinib and placebo. For previously reported BTKi-class effects, the EAIR of transient elevated alanine aminotransferase/aspartate aminotransferase TEAEs (events/100 pt-years) with evobrutinib versus placebo was 4.8 vs 2.8/3.5 vs 0.7, respectively. IgG levels were similar in evobrutinib/placebo-treated patients. CONCLUSIONS: This is the first BTKi-integrated safety analysis that includes patients with MS. Overall, evobrutinib treatment (all doses) was generally well tolerated across indications. TRIAL REGISTRATION NUMBERS: NCT02975349, NCT03233230, NCT02975336.

Efficacy and Safety of the Bruton's Tyrosine Kinase Inhibitor Evobrutinib in Systemic Lupus Erythematosus: Results of a Phase II, Randomized, Double-Blind, Placebo-Controlled Dose-Ranging Trial.

OBJECTIVE: Evobrutinib is a highly selective, orally administered Bruton's tyrosine kinase (BTK) inhibitor. The objective of this phase II, multicenter, randomized, double-blind, placebo-controlled trial was to evaluate the efficacy and safety of evobrutinib in patients with active autoantibody-positive systemic lupus erythematosus (SLE). METHODS: Patients were diagnosed with SLE by either the Systemic Lupus International Collaborating Clinics criteria or at least four American College of Rheumatology criteria 6 months or more prior to screening, had an SLE Disease Activity Index-2000 score of 6 or more, were autoantibody-positive and on standard-of-care therapy. Randomization was 1:1:1:1 to oral evobrutinib 25 mg once daily (QD), 75 mg QD, 50 mg twice daily, or placebo. Primary efficacy endpoints were SLE responder index (SRI)-4 response at week 52 and SRI-6 response at week 52 in the high disease activity subpopulation. Safety endpoints included treatment-emergent adverse events (TEAEs). RESULTS: A total of 469 patients were randomized and received at least one dose of evobrutinib or placebo at the time of primary analysis. Mean (SD) age at baseline was 40.7 (±12.3) years; 94.9% of patients were female. Neither primary efficacy endpoint was met. All doses of evobrutinib were well tolerated, and there was no clear dose effect on the incidence of reported TEAEs, or serious TEAEs, including severe infections. CONCLUSION: This phase II, dose-ranging trial in SLE failed to show a treatment effect of evobrutinib versus placebo at any dose. Evobrutinib was generally well tolerated, with no dose effect observed for TEAEs. These results suggest that BTK inhibition does not appear to be an effective therapeutic intervention for patients with SLE.