Long-term Data Demonstrates Value of Enbrel Biosimilar in Rheumatoid Arthritis Patients

Switching from etanercept to biosimilar was not associated with treatment-emergent adverse events in rheumatoid arthritis.

A biosimilar of etanercept (Enbrel) was found to be effective and well-tolerated over 2 years in patients with rheumatoid arthritis (RA).

SB4 (Benepali) is a tumor necrosis factor inhibitor approved in the European Union to treat RA, psoriatic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, and plaque psoriasis.

New data published in the Annals of the Rheumatic Disease demonstrate the long-term safety and efficacy of continuing SB4 or switching from reference product etanercept to SB4.

Included in the randomized, double-blind phase 3 study were patients with RA who received weekly subcutaneous administration of 50 mg of SB4 or etanercept with background methotrexate for up to 52 weeks.

Participants in the Czech Republic or Poland who completed the 52-week visit were enrolled in the open-label extension period and received SB4 for 48 additional weeks. The investigators assessed safety, efficacy, and immunogenicity up to week 100.

Of the 245 patients entering the extension period, 126 continued to receive SB4 and 119 switched to SB4 from etanercept, according to the report.

American College of Rheumatology (ACR) response rates were found to be comparable between the SB4/SB4 and etanercept/SB4 group, and were maintained from week 52 through week 100. ACR20 response rates at week 100 were 77.9% and 79.1%, respectively. Other efficacy results were also comparable between the groups.

The most commonly reported treatment-emergent adverse events (TEAEs) were upper respiratory tract infection, pharyngitis, RA, bronchitis, nasopharyngitis, viral infection, laryngitis, and hypertension. Serious TEAEs were reported in 1 patient in each treatment group.

There were no cases of active tuberculosis or injection-site reactions reported during the extension period. One patient in the SB4/SB4 arm died of hepatic cancer, according to the study.

A limitation to the study was the open-label nature of the extension period.

“SB4 was well-tolerated and effective over 2 years in patients with RA,” the authors concluded. “Switching from etanercept to SB4 was not associated with treatment-emergent issues such as loss of efficacy or increases in TEAEs or immunogenicity.”