Bimekizumab Efficacy in Biologic-Naive Patients With Psoriatic Arthritis

In a recent study published in the Lancet, researchers have examined the efficacy and safety of bimekizumab, a monoclonal antibody that selectively inhibits IL-17A and IL-17F, in patients with active psoriatic arthritis who have not previously undergone biologic disease-modifying antirheumatic drug (DMARD) treatment. This phase 3 trial, known as BE OPTIMAL, offers new hope for patients navigating psoriatic arthritis.

The multicenter, randomized, double-blind, placebo-controlled study, encompassing 14 countries, has been conducted in 135 sites, including hospitals, clinics, doctors' offices, and research centers. The trial focused on eligible patients who were at least age 18 years and had a documented diagnosis of adult-onset psoriatic arthritis that met the classification criteria for psoriatic arthritis for a minimum of 6 months before screening.

The patients were allocated to 1 of 3 groups: bimekizumab, administered at 160 mg every 4 weeks; placebo, given every 2 weeks; or the reference group, receiving adalimumab at 40 mg every 2 weeks. This subcutaneous treatment was administered via an interactive-voice and web-response system based on a predetermined randomization schedule.

The primary endpoint of this study was to assess the proportion of patients achieving a 50% or greater improvement in the American College of Rheumatology criteria (ACR50) at week 16, using nonresponder imputation. Between April 3, 2019, and October 25, 2021, a total of 1163 patients were screened, and 852 were assigned to the bimekizumab group (n=431), the placebo group (n=281), or the reference group (adalimumab; n=140).

At week 16, significantly more patients receiving bimekizumab (44%) reached the ACR50 response compared to those receiving a placebo (10%). The odds ratio was 7.1 (95% CI 4.6-10.9), demonstrating a substantial improvement (P<.0001). The reference group (adalimumab) also showed promising results, with 46% of patients reaching ACR50. Importantly, all secondary hierarchical endpoints were met in this study. Furthermore, the analysis of the data presented up to week 24 revealed consistent trends, indicating the potential long-term effectiveness of bimekizumab.

Regarding safety, treatment-emergent adverse events up to week 16 were reported in 60% of patients receiving bimekizumab, 49% of patients receiving a placebo, and 59% of patients receiving adalimumab. It is worth noting that no deaths were reported in this trial.

“Bimekizumab treatment had superior improvements in joint, skin, and radiographic efficacy outcomes at week 16 compared with placebo in patients with psoriatic arthritis who were naive to biologic DMARDs,” concluded the study authors. “The safety profile of bimekizumab, including the occurrence of fungal infections, was consistent with previous phase 3 studies in patients with plaque psoriasis, and with IL-17A inhibitors.”

Reference
McInnes IB, Asahina A, Coates LC, et al. Bimekizumab in patients with psoriatic arthritis, naive to biologic treatment: a randomised, double-blind, placebo-controlled, phase 3 trial (BE OPTIMAL). Lancet. 2023;401(10370):25-37. doi:10.1016/S0140-6736(22)02302-9