Study reports comparable treatment effects of biosimilars and reference biologics in rheumatoid arthritis

Adalimumab, infliximab, and etanercept biosimilars were found to have clinically equal treatment effects compared to their reference biologics for the treatment of rheumatoid arthritis (RA), according to a review and meta-analysis published in JAMA Network Open.

The study included a total of 10,642 RA patients who were using biosimilars of the drugs adalimumab, etanercept, and infliximab, and compared them to those receiving their reference biologics. The efficacy equivalency was assessed using the American College of Rheumatology standards (ACR20) (relative risk [RR] 0.94 to 1.06) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) (standard mean differences [SMD], -0.22 to 0.22). The study found similar ACR20 responses (RR 1.01) and changes in HAQ-DI scores (SMD -0.04) across 24 randomized controlled trials.

In a 24-week randomized study (2021), the effectiveness of a biosimilar called CT-P17 was compared to EU-adalimumab in terms of immunogenicity. The study included a total of 648 RA patients, with 324 patients receiving CT-P17 and 324 patients receiving EU-adalimumab. The study found that 82.7% of the patients in both groups (n = 268/324) achieved the ACR20 response rate at week 24. Overall safety and other outcomes were found to be equivalent between the two groups.

When comparing CT-P17 to EU-adalimumab, it was reported that the mean trough serum concentrations of CT-P17 were slightly higher. However, the difference was marginal. Additionally, the study found that the immunogenicity of CT-P17 was quantitatively slightly lower compared to EU-adalimumab. In patients with active RA, both CT-P17 and EU-adalimumab demonstrated comparable immunogenicity, safety, and effectiveness. The general safety profile of CT-P17 was found to be similar to the well-known safety profile of the reference drug adalimumab.

These findings provide valuable evidence supporting the use of biosimilars as viable alternatives in the management of RA, offering comparable effectiveness while maintaining similar safety and immunogenicity characteristics. It is essential to consider such evidence when making treatment decisions, as biosimilars present a promising option for improving access and affordability of effective therapies.


  1. de Oliveira Ascef B, Almeida MO, de Medeiros-Ribeiro AC, de Andrade DC, de Oliveira Junior HA, de Soárez PC. Therapeutic Equivalence of Biosimilar and Reference Biologic Drugs in Rheumatoid Arthritis: A Systematic Review and Meta-analysis. JAMA Network Open. 2023 May 1;6(5):e2315872-.
  2. Kay J, Jaworski J, Wojciechowski R, Wiland P, Dudek A, Krogulec M, Jeka S, Zielinska A, Trefler J, Bartnicka-Maslowska K, Krajewska-Wlodarczyk M. Efficacy and safety of biosimilar CT-P17 versus reference adalimumab in subjects with rheumatoid arthritis: 24-week results from a randomized study. Arthritis Research & Therapy. 2021 Dec;23(1):1-2.