Comparing Effectiveness Rituximab (Mabthera®) to Other Second-line Biologics for Rheumatoid Arthritis Treatment in Patients Refractory to or Intolerant of First-line Anti-tumor Necrosis Factor Agent: An Observational Study

ABSTRACT

OBJECTIVE: Failure of first-line anti-tumor necrosis factor (TNF) agents in in rheumatoid arthritis patients leads to decisions among second-line biologic agents. To better inform these decisions, the therapeutic effectiveness of rituximab is compared with other second-line biologic agents in this observational study. METHODS: Between November 2011 and December 2014, study subjects were observed for 12 month periods. Patients with an inadequate response to initial anti-TNF agent received either rituximab or alternative anti-TNF agents (adalimumab/etanercept/infliximab) based on the preference of patients and physicians. The efficacy end point of this study was the change in 28-joint count Disease Activity Score (DAS28) at six and 12 months from baseline. Safety data were also collected. RESULTS: Ninety patients were enrolled in the study. DAS28 at six months did not change significantly whether the patients were treated with rituximab or alternative anti-TNF agents in intention-to-treat analysis (n=34, −1.63±0.30 vs. n=31, −2.05±0.34) and standard population set analysis (n=31, −1.51±0.29 vs. n=24, −2.21±0.34). Similarly, the change in DAS28 at 12 months did not reach statistical significance (−1.82±0.35 in the rituximab vs. −2.34±0.44 in the alternative anti-TNF agents, p=0.2390). Furthermore, the incidences of adverse events were similar between two groups (23.5% for rituximab group vs. 25.8% for alternative anti-TNF agents group, p=0.7851). CONCLUSION: Despite the limitations of our study, switching to rituximab or alternative anti-TNF agents after failure of the initial TNF antagonist showed no significant therapeutic difference in DAS28 reduction.