Treatment Patterns, Direct Cost of Biologics, and Direct Medical Costs for Rheumatoid Arthritis Patients: A Real-World Analysis of Nationwide Japanese Claims Data.

The aims of this article were to characterize the patterns of treating rheumatoid arthritis with biologics and to evaluate costs using claims data from the Japan Medical Data Center Co, Ltd.Patients aged 16 to <75 years who were diagnosed with rheumatoid arthritis and prescribed adalimumab (ADA), etanercept (ETN), infliximab (IFX), tocilizumab (TCZ), abatacept, certolizumab, or golimumab between January 2005 and August 2014 were included. For the cross-sectional analysis, the annual costs of ETN, IFX, ADA, and TCZ from 2009 to 2013 were assessed. For the longitudinal analysis, patients prescribed these biologics as the first line of biologics, from January 2005 to August 2014, were included. The cost of biologic treatment over 1, 2, and 3 years (including prescription of subsequent biologics) and direct medical costs (including treatment of comorbidities) were compared between groups. Discontinuation and switching rates in each group were estimated, and multivariate analyses were conducted to estimate an adjusted hazard ratio of discontinuation and switching rates among each group. The dose of each first-line biologic treatment until discontinuation was analyzed to calculate relative dose intensity.The cross-sectional annual biologic costs of ETN, IFX, ADA, and TCZ were ~$8000 (2009 and 2013), $13,000 (2009) and $15,000 (2013), $10,000 (2009) and $11,000 (2013), and $9000 (2009) and $8000 (2013), respectively. In longitudinal analyses (n = 764), 276 (36%) initiated ETN; 242 (32%), IFX; 147 (19%), ADA; and 99 (13%), TCZ. The 1-year cumulative annual biologic costs per patient from the initial prescription of ETN, IFX, ADA, and TCZ as the first-line biologic treatment were ~$11,000, $19,000, $16,000, and $12,000. The corresponding direct medical costs over 1 year from the initial prescription were ~$17,000, $26,000, $22,000, and $22,000. Costs remained greatest in the IFX-initiation group at year 3. The discontinuation rates at 36 months with ETN, IFX, ADA, and TCZ were 37.7%, 52.3%, 55.8%, and 39.5%; the switching rates were 12.5%, 27.1%, 31.0%, and 16.7%. The mean (95% CI) relative dose intensities until discontinuation of ETN 25 mg, ETN 50 mg, IFX, ADA, and TCZ were 1.02 (0.95-1.10), 0.82 (0.79-0.85), 1.16 (1.12-1.20), 0.95 (0.90-0.99), and 0.96 (0.93-1.00).Considered costs and discontinuation and switching event rates were lowest with ETN versus IFX, ADA, or TCZ used as the first-line biologic. Despite limitations, these findings imply clinical cost-reductive benefits of ETN as the first-line biologic treatment option for rheumatoid arthritis in Japan.