Comparative efficacy and safety of biosimilar adalimumab and originator adalimumab in combination with methotrexate in patients with active rheumatoid arthritis: a Bayesian network meta-analysis of randomized controlled trials

We aimed to assess the relative efficacy and safety of biosimilar adalimumab and originator adalimumab plus methotrexate (MTX) compared to those of placebo plus MTX in patients with active rheumatoid arthritis (RA) who showed an inadequate response to MTX. We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) examining the efficacy and safety of biosimilar + MTX and adalimumab + MTX versus placebo + MTX (MTX group) in patients with active RA despite treatment with MTX. A total of eight RCTs involving 2543 patients met the inclusion criteria. The ACR20 response rate was significantly higher in the biosimilar + MTX (odds ratio [OR] 2.91, 95% credible interval [CrI] 1.57–5.74) and adalimumab + MTX (OR 2.80, 95% CrI 1.81–4.46) groups than in the MTX group, with no difference in the ACR20 response rate between the biosimilar + MTX and adalimumab + MTX groups. Biosimilar + MTX had the highest probability of being the best treatment in terms of the ACR20 response rate (surface under the cumulative ranking curve [SUCRA] = 0.7896), followed by adalimumab + MTX (SUCRA = 0.7082) and MTX (SUCRA = 0.0022). The ACR50 and ACR70 response rates showed a distribution pattern similar to that of the ACR20 response rate. Safety based on the number of serious adverse events did not differ significantly among the three interventions in the follow-up period of 12 to 24 weeks. Biosimilar and originator adalimumab, in combination with MTX, represent an effective intervention for active RA despite treatment with MTX. No significant difference was found between biosimilar and originator adalimumab in terms of efficacy and safety. However, follow-up in RCTs is short and not all safety outcomes can be assessed in RCTs. Thus, additional long-term evaluations are needed.