Bimekizumab triumphs in bDMARD-naïve psoriatic arthritis patients

Patients with psoriatic arthritis (PsA) with no prior exposure to biological disease-modifying antirheumatic drugs (bDMARDs) experience improvements in their condition when treated with bimekizumab, according to results of the phase III BE OPTIMAL trial.

“The study met all of its primary and ranked secondary endpoints [at week 16],” presented study author Professor Iain McInnes from the University of Glasgow, Glasgow, UK, at EULAR 2022.

“Bimekizumab-treated … patients … showed improvements in joint and skin outcomes, as well as in the composite outcome of minimal disease activity (MDA), reflecting the efficacy of dual [IL-17A and IL-17F] inhibition across PsA disease manifestations,” he said.

Study participants were 852 bDMARD-naïve patients aged ≥18 years (mean age 48.7 years, 46.8 percent male, mean BMI 29.2 kg/m²) with adult-onset active PsA and ≥3 tender and ≥3 swollen joints (mean disease duration 5.9 years). They were randomized 3:2:1 to receive subcutaneous bimekizumab (160 mg Q4W), placebo, or adalimumab (40 mg Q2W) for 52 weeks, with patients in the placebo group receiving bimekizumab 160 mg Q4W from week 16.

Ninety-six and 95 percent of patients completed treatment at week 16 and 24, respectively (n=821 and 806, respectively).

At week 16, ACR50* was significantly improved with bimekizumab vs placebo (43.9 percent vs 10.0 percent; p<0.001), with 45.7 percent of patients assigned to adalimumab achieving ACR50. [EULAR 2022, abstract LB0001]

A greater proportion of patients in the bimekizumab than placebo group achieved PASI90** (61.3 percent vs 2.9 percent; p<0.001). PASI90 was achieved in 41.2 percent of patients assigned to adalimumab.

More bimekizumab than placebo recipients experienced improvements in ACR20* and ACR70* at week 16 (62.2 percent vs 23.8 percent and 24.4 percent vs 4.3 percent, respectively; p_nominal<0.001 for both). Similarly, more bimekizumab than placebo recipients demonstrated improvements in PASI75** and PASI100** at week 16 (77.4 percent vs 12.9 percent and 47.5 percent vs 2.1 percent; p_nominal<0.001 for both).

At week 24, following the switch to bimekizumab among placebo recipients (8 weeks of bimekizumab), ACR50 was achieved by 35.9, 45.5, and 47.1 percent of placebo-bimekizumab, bimekizumab, and adalimumab recipients, respectively, and PASI90 achieved in 61.4, 72.8, and 47.1 percent, respectively.

ACR20 and ACR70 responses were maintained and consistent to week 24, remarked McInnes. “The placebo patients who crossed over onto bimekizumab rapidly recovered rates of response to be broadly similar to those patients who had already [responded] by week 16,” he added.

The benefit of bimekizumab vs placebo on ACR20 was evident as early as week 2 (27.1 percent vs 7.8 percent; p_nominal<0.001). ACR20 at week 2 was achieved by 33.6 percent of adalimumab recipients.

More patients on bimekizumab than placebo achieved MDA at 16 weeks (45.0 percent vs 13.2 percent; p<0.001), with responses improving in the placebo group upon switching to bimekizumab (48.5 percent vs 37.7 percent [bimekizumab vs placebo-bimekizumab] at 24 weeks). At week 16, bimekizumab also outperformed placebo in inhibiting structural progression both in the overall and at-risk*** populations.  

At week 16, treatment-emergent adverse events (TEAEs) were recorded in 59.9, 49.5, and 59.3 percent of bimekizumab, placebo, and adalimumab recipients, respectively, with a comparable and low rate of serious AEs across groups (1.6, 1.1, and 1.4 percent, respectively). The most frequently occurring (≥5 percent) AEs were nasopharyngitis (9.3, 4.6, and 5.0 percent, respectively), upper respiratory tract infections (4.9, 6.4, and 2.1 percent, respectively), and increased alanine aminotransferase levels (0.7, 0.7, and 5.0 percent, respectively).

None of the adalimumab recipients experienced Candida infections which occurred in 11 bimekizumab and two placebo recipients. There were no incidents of systemic candidiasis, major adverse cardiovascular events, uveitis, or inflammatory bowel disease, and no deaths. There was one incident of basal cell carcinoma in the bimekizumab group and one stage 1 breast cancer in the placebo group. At week 24, fungal infections were more common in bimekizumab than adalimumab recipients (5.7 percent vs 0.7 percent).

The responses of bimekizumab in this and the BE COMPLETE trial, which involved patients with inadequate response to tumour necrosis factor inhibitors, suggest that the benefits of bimekizumab for joint and skin outcomes are consistent irrespective of prior exposure to bDMARDs, concluded McInnes.