Objective: To assess cost-effectiveness of abatacept in patients with rheumatoid arthritis (RA) with inadequate response to tumor necrosis factor-alpha antagonists (anti-TNF).
Methods: We developed a simulation model to depict progression of disability [in terms of Health Assessment Questionnaire Disability Index (HAQ-DI)] in women aged 55-64 years with moderately to severely active RA and inadequate response to anti-TNF. At model entry, patients were assumed to receive either oral disease modifying antirheumatic drugs (DMARD) only or oral DMARD plus abatacept. Patients were then tracked from model entry until death. Future health-state utilities and medical-care costs (except study therapy) were estimated based on predicted values of the HAQ-DI. The model was estimated using data from a Phase III clinical trial of abatacept plus secondary sources. Cost-effectiveness was expressed in terms of incremental cost (2006 US$) per quality-adjusted life-year (QALY) gained alternatively over 10 years and a lifetime. Future costs and health effects were discounted at 3% annually.
Results: Over 10 years, abatacept would yield 1.0 additional QALY (undiscounted) per patient (4.0 vs 3.0 for oral DMARD) at an incremental (discounted) cost of $45,497 (100,648 vs $55,151) respectively; over a lifetime, corresponding figures were 1.6 QALY (5.8 vs 4.2) and $64,978 ($140,714 vs $82,489). Cost-effectiveness was [mean (95% CI)] $50,576 ($47,056, $54,944) per QALY gained over 10 years, and $45,979 ($42,678, $49,932) per QALY gained over a lifetime. Findings were robust in sensitivity analyses.
Conclusion: Abatacept is cost-effective by current standards of medical practice in patients with moderately to severely active RA and inadequate response to an anti-TNF.