Etancercept and Biosimilars Recommended for Treatment of JIA

A new European study found that etanercept and equivalent biosimilars could be recommended for the treatment of juvenile idiopathic arthritis (JIA).

The investigation, led by Daniel Windschall, PD, MD, Northwest German Rheumatology Center, St. Josef Stift, Sendenhorst, Germany, confirmed that the etanercept originator was still used more frequently, but equivalent biosimilars in pediatric patients could be recommended “without hesitation”.

This marked the first prospective study that provided data on the use of biosimilars in children.

Though the use of biologics had been improved upon in recent years, the threat of JIA in terms of severe physical damage remains a concern.

Previous studies had shown equivalent efficacy and safety of biosimilars compared to the etanercept originator, but no reference studies in pediatric patients exist.

Additionally, children show differences in pharmacokinetics and dynamics compared to adults, which prompted investigators to add important information regarding the efficacy and safety of the 2 approved etanercept biosimilars.

The Study

Initially, data were collected through the Biologics in Pediatric Rheumatology Registry (BIKER), an observational registry that existed since 2001.

Windschall and colleagues enrolled 348 patients for the study, all of whom started etancercept treatment after January 1, 2017. Among them, 293 patients received the originator Enbrel, and 55 patients received a biosimilar (Benepali, n= 27, Erelzi, n= 28).

To compare efficacy, the Juvenile Arthritis Disease Activity Score (JADAS-10) and the Childhood Health Assessment Questionnaire Disability Index (CHAQ-DI) were used. The current disease activity of JIA was assessed at baseline and at each follow-up (3 and 6 months, and every 6 months thereafter) through a visual analog scale (VAS) by indicating a rating between 0 and 100.

Finally, a statistical analysis was performed to show frequencies, percentages, median values with the 25% and 75% quartiles, and incidence rates per 100 patient-years with the 95% confidence interval.

The Findings

Regarding efficacy, Windshall and colleagues found no significant differences between patients treated with the originator or a biosimilar.

However, patients treated with etanercept had significant reduction in disease activity.

For patients who switched from Enbrel to Benepali or Erelzi, the parameters to quantify disease activity in of JIA were at a comparable level.

Despite a myriad of adverse events (AE) having occurred during treatment, the most common of which were viral infections of the upper respiratory tract, no significant difference in frequency was recorded. The clustering of AEs in patients who started with a biosimilar were mainly attributed to the injection site reactions.

The discontinuation rates were high when compared to the literature gathered by investigators. However, they attributed this difference to the shorter observation periods in the previous studies.

Overall, the data confirmed the equivalence of the etancercept biosimilars Benepali and Erelzo compared with the originator Enbrel, with the only marked difference being the local reactions at the injection site observed in patients treated with biosimilars.

Despite this, Windshall and colleagues did not consider it to have a significant impact on therapy adherence.

“In accordance with the current literature, there are thus no medical concerns for increased use of the biosimilars Benepali and Erelzi,” the team wrote. “Such increased use is particularly recommended considering the very high costs and growing inequality in access to treatment with biologics.”

The study, “Efficacy and Safety of Etancercept Biosimilars Compared With the Originator for Treatment of Juvenile Arthritis: A Prospective Observational Study,” was published online in ACR Open Rheumatology.