Efficacy and Treatment Costs of Monotherapy with bDMARDs in the Treatment of Rheumatoid Arthritis in Patients Intolerant to or Inappropriate to Continue Treatment with Methotrexate

Introduction: Only limited information is available on cost efficacy of the various biological agents used to treat patients with rheumatoid arthritis with intolerance or for whom it would be inappropriate to continue treatment with conventional agents. We estimated the efficacy and treatment costs of monotherapy with biological agents in the treatment of this group of patients. Methods: Data from two previous meta-analyses in the treatment of patients who are intolerant to methotrexate (MTX), or for whom it would be inappropriate to continue treatment with MTX was used. Pharmacoeconomic comparison between biological agents was carried out to estimate the respective cost for the number needed to treat (NNT) compared to placebo using both American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) criteria. The analysis involved the four agents approved in Italy: adalimumab (ADA), etanercept (ETN), certolizumab pegol (CTZ), and tocilizumab (TCZ). A six-month period was considered sufficient to understand the most important differences in efficacy and treatment costs. Direct medical costs, including pharmacological therapy, administration and monitoring were considered. Results: Using both ACR and EULAR criteria, TCZ (intravenous [iv]/subcutaneous [sc]) had a lower NNT than the other agents. The difference in NNT observed for ETN was more pronounced with EULAR criteria, whereas in the comparison with ADA, the most sensitive differences were observed with ACR criteria. ETN had the lowest treatment cost ((sic)6402.19), followed by ADA ((sic)6698.84), TCZ sc ((sic)6887.61), and TCZ iv ((sic)7130.83). TCZ sc had the lowest cost for NNT with both ACR and EULAR criteria. The differences compared to ETN and ADA were significant and related with the level of efficacy. Sensitivity analysis confirmed these results. Conclusion: TCZ is a cost-effective therapeutic option compared to other tumor necrosis factor-a inhibitors (ADA, ETA, CTZ) as first-line monotherapy for patients who are intolerant to MTX, or for whom it is inappropriate to continue treatment with MTX.