Cost-Effectiveness Analysis of Bimekizumab against Interleukin-23 Inhibitors in Patients with Plaque Psoriasis in Japan.

INTRODUCTION

Psoriasis is a chronic, inflammatory skin disease that significantly impairs patients' quality of life (QOL). Several biologics with varying mechanisms of action are approved for treating moderate-to-severe plaque psoriasis (PSO) in Japan; bimekizumab is the only one that selectively binds to and inhibits interleukin (IL)-17F in addition to IL-17A. However, there is currently no recommended biologics treatment sequence, and their high cost limits treatment accessibility. This study evaluated bimekizumab cost-effectiveness versus IL-23 inhibitors in patients with PSO in Japan from a public healthcare payer's perspective, and explored variables that affect cost-effectiveness.

METHODS

A cohort simulation, lifetime Markov model with 2-week cycles simulated the treatment pathway in adults with moderate-to-severe PSO who had an inadequate response to previous treatments. Bimekizumab was compared with the IL-23p19 inhibitors guselkumab, risankizumab, and tildrakizumab in the first line; brodalumab was the second-line treatment for all arms. Transition to second-line treatment was triggered by not achieving a ≥ 75% improvement in Psoriasis Area and Severity Index (PASI 75), or discontinuation due to adverse events. A network meta-analysis provided PASI response rates. QOL scores were derived from EuroQol 5-Dimension 3-Level health questionnaire responses from global bimekizumab phase 3 studies. Drug and management costs were estimated on the basis of Diagnosis Procedure Combination-based data in Japan; 2%/year discounting was applied to costs and quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios (ICERs) were calculated, and sensitivity and scenario analyses performed.

RESULTS

Bimekizumab generated the highest number of QALYs and was cost-effective against all IL-23 inhibitor comparators at a willingness-to-pay threshold of ¥5,000,000/QALY (bimekizumab versus guselkumab: ¥3,202,863/QALY; risankizumab: ¥4,732,268/QALY; tildrakizumab: ¥4,950,972/QALY). ICERs were sensitive to QOL scores, with PASI 100 QOL score being a key cost-effectiveness driver.

CONCLUSIONS

Findings of the cost-effectiveness of bimekizumab against IL-23 inhibitors support the potential consideration of bimekizumab as a first-line treatment for moderate-to-severe PSO in Japan.