OBJECTIVES: Current Finnish treatment guidelines (nivelpsoriaasi Käypä Hoito-suositus) for psoriatic arthritis (PsA) include cost-per-responder to achieve American College of Rheumatology (ACR) 50, but lack most recently approved treatments, bimekizumab and risankizumab. This analysis assesses the cost-per-responder of bimekizumab, a selective inhibitor of interleukin (IL)-17F in addition to IL-17A, against IL-17A, IL-12/23 and IL-23 inhibitors, including risankizumab for PsA in Finland.

METHODS: A cost-per-responder model was developed to include biologic-naïve patients and patients with experience of at least one previous tumour necrosis factor inhibitor (TNFi-exp). Treatments included were bimekizumab 160mg-Q4W, secukinumab 150mg/300mg-Q4W, ixekizumab 80mg-Q4W, ustekinumab 45mg/90mg-Q12W, guselkumab 100mg-Q4W/Q8W, and risankizumab 150mg-Q12W. Efficacy outcomes assessed were ACR50, Psoriasis Area and Severity Index (PASI) 100 (skin clearance) and Minimal Disease Area (MDA) at 16 weeks. Drug acquisition costs (pharmacy retail prices including VAT) obtained from HILA’s pricing database (April 2024) were used to calculate total cost-per-patient over 16 weeks. Response rates were based on bimekizumab BE OPTIMAL and BE COMPLETE trials and published network meta-analyses to calculate the number needed-to-treat, multiplied by cost-per-patient for each intervention to obtain the cost-per-responder.

RESULTS: For ACR50, bimekizumab had the lowest cost-per-responder (9.667€ for biologic-naïve and 8.826€ for TNFi-exp), whereas guselkumab 100mg-Q4W showed the highest cost-per-responder for biologic-naïve (32.499€) and ustekinumab 45mg for TNFi-exp (30.709€). For MDA, bimekizumab had the lowest cost-per-responder for both subgroups (10.411€ and 9.023€ respectively), whereas guselkumab 100mg-Q4W demonstrated the highest cost-per-responder for biologic-naïve (35.325€) and secukinumab 300mg for TNFi-exp (29.192€). For PASI100, bimekizumab had the lowest cost-per-responder (8.639€ and 7.000€), whereas secukinumab 300mg showed the highest cost-per-responder for biologic-naïve (29.192€) and ixekizumab for TNFi-exp (28.947€), respectively.

CONCLUSIONS: Based on published network meta-analysis response rates and drug acquisition costs, bimekizumab demonstrated the lowest cost-per-responder outcome among approved IL-inhibitors for patients with PsA in Finland, suggesting bimekizumab could be considered a preferred IL-inhibitor.