Budget Impact of Sequential Treatment with Biologics, Biosimilars, and Targeted Synthetic Disease-Modifying Antirheumatic Drugs in Thai Patients with Rheumatoid Arthritis

Abstract

Background: Targeted treatment of rheumatoid arthritis (RA) includes biological DMARDs (bDMARDs) and JAK inhibitors (JAKi). These agents are recommended at the same level on the basis of their efficacy and safety data. However, no local evidence of the impact of RA treatment regimens on total budget spending is available to date. This study aimed to explore the budget impact of different sequential targeted treatments in Thai patients with RA who failed at least three conventional synthetic DMARDs. Methods: We used the adapted model to evaluate the budget impact of adding tofacitinib in different order to RA targeted treatment regimens. The Thai RA population eligible for treatment was assessed on the basis of local prevalence and experts’ opinion. Cost-impact analysis was evaluated for the treatment sequences of four different lines of targeted therapies using inputs like clinical efficacy, safety, and costs. The model used a decision tree structure with treatment nodes corresponding to treatment response outcomes for a cohort of patients. The comparisons included five bDMARDs [etanercept (ETN), infliximab (IFX), golimumab (GOL), rituximab (RTX), tocilizumab (TCZ) intravenous formulation], two JAKi [tofacitinib (TOF) and baricitinib (BAR)], and two IFX biosimilars (PF-06438179/GP1111 and CT-P13). A total of 80 treatment sequences within each containing four sequential first-, second-, third-, and fourth-line options were generated. Results: The findings of the base case scenario indicated the treatment sequence with RTX as first-line, followed by IFX biosimilar (PF-06438179/GP1111), TOF, and TCZ, respectively, produced the lowest budget impact of US $693.54 million. Sensitivity analyses confirmed the robustness of our findings. Conclusion: The order of targeted therapy starting with RTX, then IFX biosimilar, TOF, and finally TCZ incurred the lowest budget impact over a 5-year time horizon for treating moderate to severe RA. Our findings may help payers and policy makers consider appropriate budget allocation on chronic non-communicable diseases, especially RA.