Abstract

OBJECTIVES: Rheumatoid Arthritis (RA) is a chronic inflammatory disease which destroys synovial joints and generates pain; RA could disable patients and could be the cause of premature death. Its prevalence for Chile has been estimated in 0.46% (IC 95% 0.24-0.8). Available drugs for treatment include conventional synthetic Disease-Modifying Antirheumatic Drugs (csDMARDs), biological therapies and a new oral janus kinase inhibitor drug approved for treatment after failure of csDMARDs: tofacitinib. The aim of this study is to determine the direct costs associated with available therapies after csDMARDs failure. METHODS: The analysis was made from third payer perspective with a time horizon of one year. Costs baskets were constructed, considering the costs of diagnosis, treatment and monitoring of the intervention and validated with rheumatologists. Drug costs were obtained from public tenders and official reports. Comparators were: tofacitinib (5mg twice/day); abatacept (750 mg weeks 0-2-4 and then every 4 weeks); adalimumab (40mg every two weeks); certolizumab (400mg at weeks 0-2, 4 and then 200mg every 4 weeks); etanercept (50mg/week); golimumab (50mg/month); infliximab (3mg/kg weeks 0-2-6 and then every 8 weeks); rituximab (1000mg weeks 0-2 and then 24 weeks after); tocilizumab 8mg/kg every 4 weeks). Dosage information was taken from Instituto de Salud Publica de Chile, an average weight of 70kg was considered for those drugs whose dose depends of weight. Results are expressed in 2014USD (exchange rate US$1 = CLP$600) RESULTS: In a time horizon of one year, the costs associated with the RA treatment were in average: US$93.83 diagnosis, US$269.19 monitoring, US$59.73 concomitant drugs. The annual cost of RA treatment with available drugs after conventional csDMARDs failure was estimated between US$9,378.4 (tofacitinib) and US$18,368.9 (abatacept) as highest and lowest options. CONCLUSIONS: For the analyzed scenario, tofacitinib is the option with lower costs, generating savings in comparison with the biological therapies available for RA after csDMARDs failure.