Sequential interleukin-17 inhibitors for moderate-to-severe plaque psoriasis who have an IL-17 inhibitors failure in a resource limited country: An economic evaluation

by Piyameth Dilokthornsakul, Ratree Sawangjit, Nopadon Noppakun, Natta Rajatanavin, Bensachee Pattamadilok, Leena Chularojanamontri, Unchalee Permsuwan

Biologics has been known to be effective for patients with psoriasis. However, optimal treatment pathways and their cost-effectiveness are limited in a resource-limited country. This study assessed the cost-effectiveness of different sequential biologics for moderate-to-severe plaque psoriasis.

A hybrid model from a societal perspective was used. Model inputs were derived from network meta-analysis, clinical trials, and published literature. Three different sequential biologic treatments were assessed; Sequence 1; 1^st Interleukin-17 (IL-17) inhibitor (secukinumab) followed by 2^nd IL-17 inhibitors (ixekizumab or brodalumab), then 3^rd IL-23 inhibitor (guselkumab), Sequence 2; ixekizumab followed by secukinumab or brodalumab, then guselkumab, and Sequence 3; brodalumab followed by ixekizumab or secukinumab, then guselkumab. Methotrexate or ciclosporin was used as standard of care (SoC).

All three different sequential biologic therapies could gain total quality-adjusted life year (QALY), but they had higher cost than SoC. Sequence 1 had the lowest incremental cost-effectiveness ratio (ICER) compared to SoC at 621,373 THB/QALY (19,449 $/QALY). ICER for Sequence 2 was 957,258 THB/QALY (29,962 $/QALY), while that for Sequence 3 was 1,332,262 THB/QALY (41,700 $/QALY). Fully incremental analysis indicated that Sequence 3 was dominated by Sequence 1 and Sequence 2. ICER for Sequence 2 was 7,206,104 THB/QALY (225,551 $/QALY) when compared to Sequence 1.

At the current willingness-to-pay of 160,000 THB/QALY, no sequential IL-17 inhibitor was cost-effective compared to SoC. Secukinumab followed by ixekizumab or brodalumab then guselkumab (Sequence 1) may be the most appropriate option compared with other treatments.