Cost-effectiveness analysis of bimekizumab for the treatment of active psoriatic arthritis in Sweden

Aims: To evaluate the cost-effectiveness of bimekizumab, an inhibitor of IL-17F and IL-17A, against biologic and targeted synthetic disease-modifying antirheumatic drugs (DMARD) for psoriatic arthritis (PsA) from the Swedish healthcare system perspective. Materials and methods: A Markov model was developed to simulate the clinical pathway of biologic [b] DMARD-naïve or tumor necrosis factor inhibitor experienced [TNFi-exp] PsA patients over a lifetime horizon. Treatment response was incorporated as achievement of the American College of Rheumatology 50% (ACR50) and Psoriasis Area and Severity Index 75% (PASI75) response, and changes in the Health Assessment Questionnaire-Disability Index (HAQ-DI) score. The efficacy of bimekizumab was obtained from the BE OPTIMAL (bDMARD-naïve) and BE COMPLETE (TNFi-experienced) trials while a network meta-analysis (NMA) informed the efficacy of the comparators. Resource use and drug costs were obtained from published studies and databases of drug retail prices in Sweden. A willingness-to-pay threshold of €50,000 per quality-adjusted life year (QALY) was applied. Results: In bDMARD-naïve patients, bimekizumab achieved greater QALYs (14.08) than with all comparators except infliximab (14.22), dominated guselkumab every 4 and 8 weeks, ixekizumab, secukinumab 300 mg, ustekinumab 45 mg and 90 mg, and was cost-effective against risankizumab, tofacitinib, upadacitinib and TNFis, except adalimumab biosimilar. In TNFi-experienced patients, bimekizumab led to greater QALYs (13.56) than all comparators except certolizumab pegol (13.84), and dominated ixekizumab and secukinumab 300 mg while being cost-effective against all other IL-17A-, IL-23- and JAK inhibitors. Limitations: An NMA informed the comparative effectiveness estimates. Given gaps in evidence of disease management and indirect costs specific to HAQ-DI scores, and sequential clinical trial evidence in PsA, non-PsA cost data from similar joint conditions were used, and one line of active treatment followed by best supportive care was assumed. Conclusions: Bimekizumab was cost-effective against most available treatments for PsA in Sweden, irrespective of prior TNFi exposure.