Objectives: This study aimed to assess the cost-effectiveness of biologic disease-modifying antirheumatic drugs (bDMARDs) for treating patients with psoriatic arthritis who failed conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).

Methods: A decision tree and Markov model were constructed to capture long-term costs and outcomes from a societal perspective. Patients with psoriatic arthritis who failed 2 previous csDMARDs were modeled over a 3-month cycle with a lifetime horizon. Clinical probabilities were derived from a published meta-analysis. Prices of bDMARDs were proposed by pharmaceutical companies. Other costs and utilities were based on data in Thailand. All costs and outcomes were discounted at a 3% annual rate. Incremental cost-effectiveness ratio and a series of sensitivity analyses were performed.

Results: All 11 bDMARDs (3 infliximab originator and biosimilars, 2 etanercept originator and biosimilar, golimumab, 2 secukinumab 150 mg and 300 mg, 3 adalimumab biosimilars) gained better quality-adjusted life-years (QALYs) with more costly than csDMARDs. Infliximab had the highest QALYs compared with other bDMARDs. Only secukinumab 150 mg showed the incremental cost-effectiveness ratio below the Thai threshold of 5152 US dollars per QALY. Cost of bDMARDs was the most influential factor.

Conclusions: At the current price, secukinumab 150 mg shows the value for money in the Thai context. Price negotiation is of great importance for other bDMARDs.