Adalimumab Biosimilar Maintains Effectiveness for Patients With Arthritis and Health Care Costs

Patients with rheumatoid and psoriatic arthritis maintained stable disease activity and functional capacity, with even some improvement in ultrasound findings, after switching from original adalimumab to its biosimilar, GP2017. | Image Credit: japhoto - stock.adobe.com

Switching from original adalimumab to its biosimilar (GP2017) demonstrated comparable effectiveness in managing rheumatoid and psoriatic arthritis, with stable disease activity, functional capacity, and radiographic progression, alongside an observed improvement in power Doppler findings on ultrasonography, according to a study published in Reumatismo.¹

Biologic disease-modifying antirheumatic medications (bDMARDs) have become a mainstay in the treatment of moderate to severe rheumatoid arthritis, especially for patients who do not respond well to conventional synthetic DMARDs.² These biologics have shown impressive success in reducing disease activity and improving patients’ quality of life. Biosimilars provide significant cost savings potential since they typically enter the market between 20% and 40% less expensive than their originator biologics. As the patents on some well-known biologics—including adalimumab, etanercept, and infliximab—have expired, a number of biosimilars have already been approved and introduced into certain international markets.

Studies show that most patients with stable inflammatory rheumatic joint diseases successfully switched to an adalimumab biosimilar.³ This positive outcome suggests that biosimilars can not only improve patient health but also provide significant cost savings compared with the reference drug, benefiting health care systems and patients alike.

Imaging, especially ultrasonography, is increasingly vital in rheumatology for assessing disease activity and treatment response.¹ However, the effect of switching from original adalimumab to a biosimilar on these imaging parameters hasn't been thoroughly studied. To address this gap, researchers conducted a prospective cohort study to evaluate the clinical, functional, ultrasonographic, and radiological responses in patients with rheumatoid arthritis and psoriatic arthritis who transitioned from original adalimumab to the biosimilar GP2017.

From a group of 270 patients with rheumatoid arthritis, 35 who switched to the biosimilar adalimumab (GP2017) had complete pre- and post-switch disease control data. This was also true for 15 patients with psoriatic arthritis. There were no statistically significant changes in either median disease activity (Disease Activity Score-28, 3.7 vs 3.5; P = .6) or functional capacity (HAQ, 0.8 vs 1.1; P = .7) after the switch.

Looking at imaging, X-rays showed no change in erosions (47% vs 48%; P = .7). However, ultrasound examinations indicated decreased disease activity after the switch, specifically by power Doppler (27% vs 12%; P= .03), though not by greyscale evaluation. Other measures, including acute phase reactants, tender and swollen joint counts, and patient-reported Visual Analog Scale for activity, remained consistent between visits.

This study's findings are limited by its small sample size from a single center, focusing only on patients starting biological therapies. This introduces selection and indication biases, making it difficult to generalize the results to a wider patient population. The small sample also reduces the study's ability to detect subtle differences from biosimilar switching, highlighting the need for larger, multicenter studies. Furthermore, the lack of a control group that continued on the original adalimumab makes it hard to determine if observed outcomes were due to the biosimilar switch or other factors. Finally, the study's limited 1-year evaluation period and lack of ongoing follow-up constrain its long-term insights.

“The study suggests that transitioning from original adalimumab to biosimilar adalimumab (GP2017) as the first-line biological treatment for rheumatoid arthritis and psoriatic arthritis patients does not appear to lead to significant alterations in disease activity or functional capacity,” study authors concluded.

References

1. Garcia-Salinas R, Magri S, Ruta A, Ruta S. A comprehensive evaluation of the transition to a biosimilar of adalimumab in rheumatoid arthritis and psoriatic arthritis: a single-center experience with a focus on imaging outcomes. Reumatismo. Published online May 8, 2025. doi:10.4081/reumatismo.2025.1748
2. Ntais C, Kontodimopoulos N, Fanourgiakis J, Talias MA. Fostering healthcare system sustainability through efficient practices: can adopting biosimilars ease the financial burden of rheumatoid arthritis? F1000Res. 2025;13:1128. doi:10.12688/f1000research.156983.2
3. van Adrichem RCS, Voorneveld HJE, Waverijn GJ, Kok MR, Bisoendial RJ. The non-medical switch from reference adalimumab to biosimilar adalimumab is highly successful in a large cohort of patients with stable inflammatory rheumatic joint diseases: a real-life observational study. Rheumatol Ther. 2022;9(4):1109-1118. doi:10.1007/s40744-022-00465-6