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).
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.
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.
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.