Budget Impact of Secukinumab in Psoriatic Arthritis Patients with Contraindication to TNF-Alpha Inhibitors

Background: Secukinumab, an IL-17A inhibitor, has been recommended for psoriatic arthritis (PsA) patients with contraindications to TNF-alpha inhibitors (TNFi). However, its budgetary implications in Thailand remain unclear. Objective: To estimate the 5-year budget impact of introducing secukinumab 150 mg for PsA patients contraindicated to TNFi therapy from the perspective of the Thai healthcare system. Methods: A budget impact analysis (BIA) was developed following the Thai HTA Guideline. Two treatment scenarios were compared: the current standard of care using csDMARDs and a new scenario incorporating secukinumab 150 mg (auto-injector). The model estimated eligible patients based on national demographics and clinical data. Costs included direct medical costs for medications, administration, monitoring, and complications. Net budget impact (NBI) was estimated. Deterministic sensitivity analyses were conducted to evaluate the impact of varying uptake rates and treatment durations. Results: Under the base-case scenario over five years, secukinumab use resulted in the NBI of 15.14 million THB (434,965 USD), with an average annual net budget impact of 3.03 million THB (86,993 USD). Drug acquisition accounted for 97.16% of the total budget impact. Sensitivity analyses revealed a higher financial burden with increased uptake or lifetime treatment but remained within a manageable range (up to 18.34 million THB or 526,849 USD). Conclusion: Introducing secukinumab for PsA patients contraindicated to TNFi is associated with a moderate increase in healthcare expenditure. These findings suggest that inclusion of secukinumab in the National List of Essential Medicines for this specific population may be feasible, conditional on successful price negotiation and/or managed entry arrangements to ensure budgetary sustainability and equitable access. Plain Language Summary: This study evaluated the 5-year budget impact of introducing secukinumab, an interleukin-17A inhibitor, for psoriatic arthritis (PsA) patients contraindicated to TNF-alpha inhibitors (TNFi) in Thailand. A budget impact analysis was developed in accordance with the Thai Health Technology Assessment (HTA) Guideline, comparing the current standard of care with conventional DMARDs (csDMARDs) against a new scenario incorporating secukinumab 150 mg (auto-injector). Eligible patient numbers were estimated using national demographic and clinical data, while direct medical costs included medications, administration, monitoring, and treatment of complications. Results showed that introducing secukinumab led to a net budget impact (NBI) of 15.14 million THB (434,965 USD) over five years, averaging 3.03 million THB (86,993 USD) annually. Drug acquisition accounted for 97% of the increased expenditure. Sensitivity analyses indicated that higher uptake rates or lifetime treatment duration moderately increased costs but remained within a manageable range (up to 18.34 million THB or 526,849 USD). The findings suggest that while secukinumab adoption modestly increases healthcare costs, it provides a valuable therapeutic alternative for PsA patients who cannot use TNFi. Policy implications include supporting its inclusion in Thailand’s National List of Essential Medicines with price negotiation strategies to ensure affordability and access. Keywords: psoriatic arthritis, secukinumab, TNF-alpha inhibitor, budget impact analysis, Thailand, pharmacoeconomics, health technology assessment