Background The multiple joint and skin manifestations of psoriatic arthritis (PsA) place a substantial burden on patient quality of life.[1] Bimekizumab (BKZ) is a monoclonal IgG1 antibody that selectively inhibits IL-17F in addition to IL-17A.

Objectives To examine the association between achieving increasingly stringent clinical disease control criteria and patient-reported measures of physical function, pain and fatigue in patients (pts) with PsA, using Week (Wk) 52 data from BE OPTIMAL.

Methods BE OPTIMAL (NCT03895203) comprised a 16-wk double-blind placebo (PBO)-controlled period and a 36-wk treatment blind period. Pts were ≥18 years, biologic disease-modifying antirheumatic drug naïve, with adult-onset, active PsA, ≥3 tender and ≥3 swollen joints. Pts were randomised 3:2:1, subcutaneous BKZ 160 mg every 4 weeks (Q4W):PBO:reference arm (adalimumab 40 mg Q2W). From Wk 16, PBO pts received BKZ 160mg Q4W. In this post hoc analysis, all pts who reached specified disease control criteria (ACR: ACR20 not reached [<ACR20], ACR20 reached but not ACR50 [ACR20–<ACR50], ACR50 reached but not ACR70 [ACR50–<ACR70], ACR70 reached [ACR70]; ACR50 and Psoriasis Area and Severity Index 100 [ACR50+PASI100]: non-responder, responder; Disease Activity in PsA [DAPSA]: high, moderate and low disease activity or remission [HDA, MoDA and LDA/REM, respectively]; Minimal Disease Activity [MDA]: non-MDA, MDA) at Wk 52 were pooled regardless of treatment arm. Associations between achieving these criteria and improvements in the following patient-reported physical function and symptom measures were assessed: Health Assessment Questionnaire Disability Index (HAQ-DI), Pt’s Assessment of Arthritis Pain Visual Analog Scale (Pain VAS) and Functional Assessment of Chronic Illness Therapy-Fatigue subscale (FACIT-Fatigue). It should be noted that some aspects of the disease control criteria relate to aspects of HAQ-DI and PtAAP. Observed case data were reported.

Results 821/852 (96.4%) pts completed Wk 16; 761 (89.3%) completed Wk 52. Baseline mean (SD) HAQ-DI (0 [best] to 3 [worst]), Pain VAS (0 [best] to 100 [worst]) and FACIT-Fatigue (0 [worst] to 52 [best]) scores were 0.85 (0.59), 55.2 (23.9) and 37.0 (9.7). Pts achieving higher ACR response thresholds demonstrated sequentially greater mean (95% CI) improvements from baseline in HAQ-DI, Pain VAS and FACIT-Fatigue (Figure 1). Similar improvements from baseline in HAQ-DI, Pain VAS and FACIT-Fatigue were seen with the achievement of ACR50+PASI100, increasingly stringent DAPSA thresholds and the achievement of MDA (Figure 1).

Conclusion Patients with active PsA who achieved increasingly stringent disease control criteria at Wk 52 reported concomitantly greater improvements in patient-reported measures of physical function, pain and fatigue.

Reference [1]Tillett W. Rheumatol Ther 2020;7(3):617–37.