SAT0403 EFFICACY AND SAFETY OF 108 WEEKS’ BIMEKIZUMAB TREATMENT IN PATIENTS WITH PSORIATIC ARTHRITIS: INTERIM RESULTS FROM A PHASE 2 OPEN-LABEL EXTENSION STUDY

Abstract

Background:Bimekizumab (BKZ), a monoclonal antibody that selectively neutralises IL-17A and IL-17F, has shown clinical improvements in skin and joint outcomes over 48 weeks (wks) in patients (pts) with active psoriatic arthritis (PsA).1Objectives:To report 2-year interim results from a phase 2b dose-ranging study (BE ACTIVE;NCT02969525) and open-label extension (OLE;NCT03347110) of BKZ in pts with PsA.Methods:Design of the dose-ranging study is described elsewhere.1Pts who completed 48 wks’ BKZ treatment without meeting withdrawal criteria were eligible for OLE entry. All OLE pts received BKZ 160 mg Q4W, irrespective of prior dosing regimen.Data are presented from dose-ranging study baseline (BL) to OLE Wk 60 (Wk 108 total). Efficacy outcomes are reported for the full analysis set (FAS): pts who received ≥1 dose BKZ (specifically those randomised to 160 mg, 160 mg with 320 mg loading dose [LD], or 320 mg at BL), with BL efficacy measurements to allow subsequent determination of ACR50. Outcomes include ACR20/50/70, body surface area (BSA) 0%, minimal disease activity (MDA), and enthesitis/dactylitis resolution. Rates of treatment-emergent adverse events (TEAEs) are reported for the Safety Set (SS; pts who received ≥1 dose BKZ in the dose-ranging study).Results:BL mean (SD) tender/swollen joint counts were 21.7 (15.7) and 11.2 (8.4). 80 (65.0%) pts had BSA ≥3% and dactylitis/enthesitis were present in 41 (33.3%) and 68 (55.3%) pts. Over 108 wks’ BKZ treatment, improvements were observed in skin/joint outcomes: ACR50 (66.7%), BSA 0% (75.4%), MDA (65.6%), and resolution of dactylitis (65.9%) and enthesitis (77.9%) (Table). Serious TEAEs occurred in 9.3% pts (Table); no deaths or major adverse cardiac events were reported. Oral candidiasis occurred in 16 (7.8%) pts (no serious cases).Conclusion:BKZ leads to long-term efficacy for skin/joint manifestations of PsA, with >50% pts achieving high thresholds of disease control (ACR50, BSA 0%, MDA) after 108 wks’ treatment. The safety profile reflects previous observations.1