We aimed to assess the relative efficacy and safety of biosimilar rituximab and originator rituximab plus methotrexate (MTX) compared to those of placebo plus MTX in patients with active rheumatoid arthritis (RA).
We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) that examined the efficacy and safety of biosimilar+MTX and rituximab+MTX versus placebo+MTX (MTX group) in patients with active RA despite treatment with MTX and/or tumor necrosis factor (TNF) blockers.
Six RCTs involving 1,747 patients met inclusion criteria. The American College of Rheumatology 20% (ACR20) response rate was significantly higher in the biosimilar+MTX (odds ratio (OR) 4.30, 95% credible interval (CrI) 1.75 - 10.91) and rituximab+MTX (OR 4.07, 95% CrI 2.51 - 7.18) groups than in the MTX group, with no difference in the ACR20 response rate between the biosimilar+MTX and rituximab+MTX groups. The biosimilar+MTX group had the highest probability of being the best treatment based on the ACR20 response rate (surface under the cumulative ranking curve (SUCRA) = 0.7832), followed by rituximab+MTX (SUCRA = 0.7134) and MTX groups (SUCRA = 0.0034). ACR50 and ACR70 response rates showed a distribution pattern similar to ACR20 response rate. Safety based on number of adverse events did not differ significantly among the three interventions after 24 weeks.
Biosimilar and originator rituximab, combined with MTX, represent an effective intervention for active RA despite treatment with MTX or TNF blockers. No significant difference was found between biosimilar and originator rituximab regarding efficacy and safety.