Another European Study Finds SB4 Tolerated by Most Patients

Another study from Europe found that biosimilar etanercept was effective and well-tolerated in the majority of patients who switched from originator etanercept.

The study looked at Samsung Bioepis’ biosimilar, SB4, which is sold as Benepali in European countries. Other studies coming out of Europe have also found SB4 to work well for the majority of patients who switched from the originator etanercept, Enbrel. The anti-tumor necrosis factor (anti-TNF) inhibitor, is currently prescribed in the United States for rheumatoid arthritis (RA), juvenile idiopathic arthritis, psoriatic arthritis (PsA), ankylosing spondylitis, and plaque psoriasis.

An observational study conducted in Poland looked at patients being treated for RA, juvenile idiopathic arthritis, PsA, or ankylosing spondylitis, in which the originator etanercept replaced SB4.

Etanercept was replaced with SB4 in 162 patients (Group 1), and in another 6 patients SB4 was the initial biologic used (Group 2). Efficacy and safety were assessed over a 6-month period.

The biosimilar was effective and well-tolerated in the majority of patients, however, for 24 patients in Group 1 (14.8%), returning to the originator was necessary due to loss of efficacy or adverse events.

Previous observational studies have found rates of discontinuing the biosimilar ranging from 2-14%. Specifically in this study:

• 9 patients experienced clinically confirmed loss of efficacy
• 9 patients reported subjective loss of efficacy
• 13 patients reported adverse events, the most common of which were headache and skin lesions.
• 4 patients had injection site reactions.

Of the 24, returning to the originator reversed the loss of efficacy or resolved the adverse event. No adverse events were reported in the 6 patients for whom the biosimilar was the initial therapy (Group 2), and the biosimilar was effective in these patients.

The authors conclude that SB4 was effective and well-tolerated in most patients, but that further research is required to investigate the effects of switching patients between originators and biosimilars.

Reference

Felis-Giemza A, Chmurzyńska K, Nałęcz-Janik J, et al. Observational study of inflammatory arthritis treatment by etanercept originator switched to an etanercept biosimilar. Reumatologia. 2019;57(5):257—263. doi:10.5114/reum.2019.89516.