Short-Term Cost per Responder of Lebrikizumab versus Tralokinumab for Moderate-to-Severe Atopic Dermatitis in Saudi Arabia: A Model-Based Payer Analysis.

PURPOSE: Atopic dermatitis (AD) imposes a clinical and economic burden, and biologic acquisition costs influence payer decisions. This study compared the short-term cost per responder of lebrikizumab and tralokinumab for moderate-to-severe AD in Saudi Arabia. METHODS: A cost-per-responder model used a Saudi payer perspective and publicly available Saudi Food and Drug Authority (SFDA) list prices, which may differ from negotiated or tender prices. Lebrikizumab 250 mg every two weeks and tralokinumab 300 mg every two weeks were compared before week-16 response assessment. Response probabilities were obtained from the 2025 network meta-analysis by Silverberg et al. EASI probabilities were reported directly; IGA 0/1 and pruritus NRS ≥4 probabilities were reconstructed from NMA relative effects and placebo risks. The primary endpoint was EASI 75 at week 16. In addition to the 16-week framework, exploratory pruritus analyses aligned week-4 response with costs through weeks 0 and 2, separately assessed inclusion of the week-4 dose, and tested whole-pack acquisition. Deterministic sensitivity, price-scenario, threshold, and fixed-budget analyses were performed. RESULT: Lebrikizumab had higher modelled response probabilities across endpoints, whereas tralokinumab had a lower administered-dose acquisition cost before week 16 (SAR 19,858.50 vs SAR 44,130). Tralokinumab had lower costs per responder for EASI 50 (SAR 41,632 vs SAR 69,169), EASI 75 (SAR 63,649 vs SAR 94,903), EASI 90 (SAR 113,477 vs SAR 148,087), and IGA 0/1 (SAR 71,346 vs SAR 96,876). After correction of the available-case placebo denominator, week-4 pruritus response probabilities were 29.6% for lebrikizumab and 13.5% for tralokinumab. Using 16-week administered-dose costs, cost per pruritus responder was similar but marginally lower with tralokinumab (SAR 147,214 vs SAR 149,128). In the time-aligned analysis before the week-4 assessment, fractional-pack costing favoured tralokinumab (SAR 49,071 vs SAR 59,651), whereas whole-pack costing favoured lebrikizumab (SAR 59,651 vs SAR 65,429). CONCLUSION: Under the modelled public Saudi list prices, tralokinumab had a lower short-term cost per responder for the week-16 skin-response endpoints. The pruritus result was exploratory and changed according to the cost horizon and pack-purchasing convention; it does not establish a consistent economic advantage for either treatment. The findings are price dependent and should not be interpreted as overall clinical superiority or long-term cost-effectiveness.