In Real-Life Setting of Patients With RA, Biosimilar SB4 Has Comparable Safety and Efficacy to Enbrel

A recent study from Romania examined the efficacy and safety of biosimilar etanercept SB4 compared to originator etanercept in a real-life cohort of patients with rheumatoid arthritis (RA).

Romania reimburses both the original etanercept (Enbrel) as well as the biosimilar, which is made by Samsung Bioepis. The biosimilar is approved in multiple regulatory territories under the names Benepali, Brenzys, and Eticovo. The biosimilar earned its first approval in the Republic of Korea in 2015, followed by approvals in the European Union, Canada, Australia, and other markets 2016, and the United States in 2019 (where it is not yet launched). In Romania, it has been available since 2017.

In this study, the authors noted that a phase 3 trial concluded that SB4 had equivalent efficacy, reduced immunogenicity, and a comparable safety profile to the reference. However, they also noted that real-life eligibility criteria are different in Romania, with possible lower joint counts, possible higher disease duration, and the required use of at least 2 conventional disease-modifying antirheumatic drugs (DMARDs) in patients with RA prior to the use of any biologics.

Researchers used national registry data for patients who started treatment with either the reference product or SB4 between July 2017 and April 2019. The study included 242 patients with efficacy and safety data after 6 months of treatment: 123 (50.8%) with the original etanercept, and 119 (49.2%) with SB4.

There were no significant differences after 6 months regarding composite scores of RA activity between patients using either drug (eg, remission defined by disease activity score in a count of 28 joints (DAS28): 18.7% in the reference group group and 17.6% in the biosimilar group, P = .823; Boolean remission: 11.4% in the reference group and 11.8% in the biosimilar group, P = .926). There were 11 adverse events (AE) in patients receiving the reference product (including 3 severe AEs: lower respiratory tract infection, enterocolitis, and anaphylaxis) and 12 AEs in the SB4 group (including 4 severe AEs: lower respiratory tract infection, vasculitis, anaphylaxis, and rash).

Compared to patients starting treatment with the originator project product, patients using the biosimilar product were more frequently naïve to biologics, had a significantly higher prevalence of positivity to anti-citrullinated protein antibodies, and had more active disease, the researchers said. Higher disease activity probably stemmed from the fact that there was a higher prevalence of biologic-naïve patients at baseline.

The researchers also discussed the role of cost in making decisions about whether to use a biosimilar; although noting the savings that are available, the authors wrote that "a safe strategy for now would be to initiate bDMARD [biologic]-naïve patients on biosimilars and to continue reference products until their natural outcome (switch due to loss of efficacy and AE, tapering and stopping due to sustained remission). This strategy should by tested by pharmaco-economic studies in different countries and therapeutic decisions should involve the patient."

Reference

Codreanu C, Popescu CC, Mogosan C, et al. Efficacy and safety of original and biosimilar etanercept (SB4) in active rheumatoid arthritis: A comparison in a real-world national cohort [published online October 24, 2019]. Biologicals. doi: 10.1016/j.biologicals.2019.10.009.