Bimekizumab safety and efficacy in patients with psoriatic arthritis: 3-year results from two phase 3 studies.

OBJECTIVES

Bimekizumab, a monoclonal IgG1 antibody that selectively inhibits IL-17F in addition to IL-17A, has demonstrated tolerability and clinical efficacy in patients with PsA. Here, we report an additional year of safety and efficacy of bimekizumab treatment to 3 years.

METHODS

BE OPTIMAL [NCT03895203; biologic DMARD (bDMARD)-naïve] and BE COMPLETE [NCT03896581; prior inadequate response/intolerance to TNF inhibitors (TNFi-IR)] assessed s.c. bimekizumab 160 mg every 4 weeks in patients with PsA. Study completers could enrol in the BE VITAL open-label extension (NCT04009499). Outcomes were reported as observed, or using modified non-responder or multiple imputation, to 3 years.

RESULTS

Overall, 546/299 (76.7/74.8%) bDMARD-naïve/TNFi-IR patients randomized to bimekizumab or placebo at baseline (Bimekizumab Total group) completed year 3. Treatment-emergent adverse event rates [exposure-adjusted incidence rate/100 patient-years (95% CI)] for bimekizumab-treated patients through 3 years were 164.2 (152.7-176.3) in bDMARD-naïve and 88.6 (79.1-98.9) in TNFi-IR patients, consistent with those at year 1 with no new safety signals identified. Response rates for efficacy outcomes were sustained up to 3 years; at year 1 and year 3, respectively, 56.1/50.4% and 53.2/55.2% of bDMARD-naïve/TNFi-IR patients achieved ACR50, 61.8/58.2% and 59.5/59.1% achieved swollen joint count resolution, and 64.7/66.2% and 61.9/67.5% had 100% improvement from baseline in Psoriasis Area and Severity Index. Responses for other efficacy measures were similarly sustained and consistent in bDMARD-naïve and TNFi-IR patients.

CONCLUSION

Bimekizumab demonstrated sustained high levels of efficacy and tolerability to 3 years, supporting its suitability for long-term treatment in bDMARD-naïve and TNFi-IR patients with PsA.

TRIAL REGISTRATION: BE OPTIMAL: NCT03895203; BE COMPLETE: NCT03896581; BE VITAL: NCT04009499.