Biosimilar Etanercept, LBEC0101, Is Safe and Effective Up to Week 100 in RA

LG Chem’s biosimilar etanercept, LBEC0101, referencing Enbrel, recently gained approval in Japan and the Republic of Korea. Among the data that led to its authorization were those deriving from a phase 3 study that demonstrated the biosimilar had equivalent efficacy and a comparable safety profile to the reference product. Recently, researchers reported on a single-arm, open-label extension study in patients with rheumatoid arthritis (RA) who completed the 52-week phase 3 study.

A total of 148 patients entered the extension; 70 had been treated with the biosimilar and continued to receive the biosimilar as maintenance. The remaining 78 patients, all of whom had been treated with the reference etanercept, switched to the biosimilar. The patients, who self-administered 50 mg of the biosimilar and received concomitant methotrexate at a stable dose, were assessed up to week 100. Safety was evaluated up to week 102.

In both the biosimilar-only and the switch group, improvements in Disease Activity Score in a count of 28 joints (DAS28) that were observed in the phase 3 trial were maintained in the extension phase. At week 100, the least squares mean changes from week 52 in DAS28 with erythrocyte sedimentation rate were −0.052 (95% CI, −0.314 to 0.210) in the maintenance group and −0.149 (95% CI, −0.417 to 0.119) in the switch group. The estimated treatment difference between groups was 0.097 (95% CI, −0.200 to 0.393).

Response rates by American College of Rheumatology criteria and European League Against Rheumatism criteria were also similar between groups.

In the 52-week study, 90% and 89.7% of patients in the biosimilar-only and switch groups, respectively, reported adverse events (AEs). During the extension, 70.0% and 70.5%, respectively, reported AEs. The most commonly reported AEs were upper respiratory tract infection, nasopharyngitis, and arthralgia. Most AAEs were mild in severity.

In the present study, in the switch group, 5 patients reported a total of 10 injection-site reactions. One patient in the biosimilar-only group reported such a reaction.

During the extension, 1 patient in the biosimilar-only group and 1 patient in the switch group developed new anti-drug antibodies. No patients had neutralizing antibodies.

These results, write the authors, confirm that efficacy previously demonstrated for the biosimilar, both in patients who received maintenance therapy and in those who switched from the reference. The biosimilar was well tolerated, and no new safety concerns were identified.

Reference

Park MC, Matsuno H, Kim J, et al. Long-term efficacy, safety and immunogenicity in patients with rheumatoid arthritis continuing on an etanercept biosimilar (LBEC0101) or switching from reference etanercept to LBEC0101: an open-label extension of a phase III multicentre, randomised, double-blind, parallel-group study. Arthritis Res Ther. 2019;21(1):122. doi: 10.1186/s13075-019-1910-2.