OBJECTIVES: To evaluate the cost-effectiveness of introducing tofacitinib for the treatment of Psoriatic Arthritis (PsA) after failure or intolerance of conventional synthetic Disease-Modifying Antirheumatic Drugs (csDMARD), in comparison to anti-TNF biologic treatments (bDMARDs), from the Spanish National Health System (NHS) perspective.

METHODS: A lifetime Markov model was developed. A panel of experts defined two sets of six treatment lines, where only the first line was different to compare tofacitinib versus adalimumab and infliximab. After six months of no response, patients switched to next treatment line. Response was evaluated using both 20% and 50% improvement in American College of Rheumatology criteria (ACR20 and ACR50, respectively) as the efficacy measures. Comparative efficacy data were inferred from a network meta-analysis and utilities were obtained from a post-hoc analysis of tofacitinib OPAL-BROADEN clinical trial. Direct medical resources and local unitary costs (€, 2018) were applied. Costs and outcomes were discounted at 3% and a 25.000€/quality-adjusted life-years (QALY) threshold value was considered. Probabilistic sensitivity analysis were conducted.

RESULTS: Adalimumab is associated with a small gain in QALYs (0.06 and 0.04 for ACR20 and ACR50 respectively), while tofacitinib is associated with a reduction in costs of 2,036.56€ and 2,048.61€. Similarly, infliximab generated small QALYs differences (0.39 and 0.07 for ACR20 and ACR50 respectively) while tofacitinib is associated with substantial costs-savings (21,217.92€ and 9,176.51€). Sensitivity analysis confirmed a probability of being cost-effective for tofacitinib of 64.2% and 74.3% vs adalimumab and of 99.6% and 99.7% vs infliximab for ACR20 and ACR50, respectively.

CONCLUSIONS: Tofacitinib efficiency increases when using ACR50 instead of ACR20 as the efficacy outcome. When considering ACR50, tofacitinib is the most cost-saving therapeutic option to treat PsA in bDMARD-naïve population in comparison to adalimumab and infliximab, with a comparable QALYs gain and a probability of being cost-effective over 70% from the Spanish NHS perspective.