Phase 3 Data Favor Bimekizumab Over Placebo in Biologic-Naïve Patients With Psoriatic Arthritis

Patients who have not yet received treatment with a biologic for their psoriatic arthritis (PsA) may respond favorably to a dual interleukin (IL)-17A and IL-17F inhibitor, according to findings from the phase 3 BE OPTIMAL study.

BE OPTIMAL—the first placebo-controlled phase 3 study of bimekizumab in patients with active PsA—showed that bimekizumab was superior to placebo, yielding favorable improvements across joint, skin, and radiographic outcomes. All primary and ranked secondary endpoints of the study were met at week 16, which were sustained or improved through week 24 and were coupled with patient-reported improvements compared with placebo.

“The results provide evidence for the efficacy of bimekizumab in reducing psoriatic arthritis disease state severity, as well as the prevention of structural damage, within the study timeframe,” the study authors wrote. “Improved physical function and reductions in the key symptoms of pain and fatigue accompanied the improvements in clinical outcomes, reducing patient-reported disease burden; pain and fatigue have both been identified by patients as important to how they experience their disease. Therefore, bimekizumab addresses the key treatment goals outlined in international guidelines and might provide a suitable treatment option for psoriatic arthritis.”

Data from more than 800 patients from the 52-week study were analyzed, with 430 receiving bimekizumab, 281 receiving placebo, and 140 receiving reference treatment with adalimumab. Administered subcutaneously at 160 mg every 4 weeks, bimekizumab led to significantly more patients (44%) achieving a 50% improvement in the American College of Rheumatology (ACR50) response criteria—the study’s primary endpoint—compared with placebo (10%) at 16 weeks; 46% of patients in the reference group achieved ACR50. Apparent differences between bimekizumab and placebo were seen as early as week 2, after a single dose of bimekizumab, for ACR20.

The researchers noted that more patients in their study had polyarticular PsA than might be seen in routine clinical practice, and that patients with severe comorbidities were excluded from the study.

“These demographics and characteristics, along with the limited study diversity, might result in differences between the study population and patients presenting in clinical practice,” the study authors wrote. “The inclusion of an active reference group goes some way to alleviating potential differences by allowing numerical comparisons of bimekizumab with a commonly used standard-of-care treatment. However, the absence of a formal, statistical comparison between treatments in this study prevents direct comparison.”

Data from the study also showed favorable outcomes across the study’s secondary endpoints. Among patients with psoriasis that affected at least 3% BSA, nearly half (47%) of those receiving bimekizumab achieved complete skin clearance—determined by Psoriasis Area and Severity Index (PASI100)—at week 16, compared with just 2% of patients receiving placebo; 21% of patients in the reference group achieved the mark. At week 24, more than half (56%) of patients receiving bimekizumab reached PASI100 compared with 38% of patients in the adalimumab reference group, though the researchers noted that the study was not powered to form statistical comparisons between the 2 treatments.

Minimal disease activity (45% vs 13%, p<0·0001; adalimumab 45%) and very low disease activity (15% vs 1%; adalimumab 16%) were also achieved at a higher rate among patients receiving bimekizumab than those receiving placebo at 16 weeks. By week 24, almost half (48%) of patients receiving bimekizumab had minimal disease activity and 22% had very low disease activity.

The researchers also observed improvements with bimekizumab when switching from placebo at week 16. For example, 38% achieved minimal disease activity and 12% achieved very low disease activity between week 16 and week 24 after switching to bimekizumab. Among the 140 patients with at least 3% BSA, 43% achieved PASI100 by week 24 after switching to bimekizumab at week 16, with some patients showing improvements as early as week 20.

Safety data showed that through week 24, bimekizumab was well tolerated, and the safety profile was comparable to what was seen in previous studies in these patients.

Reference

McInnes I, Asahina A, Coates L, et al. Bimekizumab in patients with psoriatic arthritis, naive to biologic treatment: a randomised, double-blind, placebo-controlled, phase 3 trial (BE OPTIMAL). Lancet. Published online December 5, 2022. doi: 10.1016/S0140-6736(22)02302-9