Biosimilars Report: 52-Week Long Study Results Support Etanercept Biosimilar

Switching from a biologic to a biosimilar did not affect safety or efficacy in a clinical trial of a rheumatoid arthritis biosimilar for etanercept (Enbrel, Amgen), shows a new study. (©ChaowalitSeenehaShutterstock.com)

Switching from a biologic to a biosimilar did not affect safety or efficacy in a clinical trial of a rheumatoid arthritis biosimilar for etanercept (Enbrel, Amgen), shows a new study.

This was an open-label extension study of a 52-week double-blind, randomized, parallel phase three trial of 78 rheumatoid arthritis patients who were switched from etanercept to an etanercept biosimilar. And, 70 patients who were continued on the biosimilar at 50 mg weekly with methotrexate for 48 weeks.

Conducted by Yeong Wook Song, of Seoul National University, Korea, the study was published in May in Arthritis Research and Therapy. The biosimilar, LBEC0101, which is not yet available in the U.S., has been approved in Korea and Japan for rheumatoid arthritis.

THE RESULTS

Both groups maintained DAS28-ESR from week 52 to week 100 (from 3.068 to 3.103 in the maintenance group vs. from 3.161 to 3.079 in the switch group). ACR response rates at week 100 for the maintenance vs. switch groups were 79.7% vs. 83.3% for ACR20; 65.2% vs. 66.7% for ACR50; and, 44.9% vs. 42.3% for ACR70.

The incidence of adverse events and the proportion of patients with newly developed antidrug antibodies were similar in the maintenance and switch groups (70.0% and 70.5%, 1.4% and 1.3%, respectively).

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RELATED STUDIES

Research on biosimilars for rheumatology conditions has moved quickly over the last two years when there was uncertainty and concern among healthcare providers over whether patients could safely switch from an originator biologic to a biosimilar. There were concerns about unknown adverse events and whether biosimilars could indeed sustain remission established with traditional biologics.

The Korean study (by Min-Chan Park, et al.) is among several studies that have been published documenting the safety and efficacy of long-term treatment with a biosimilar and switching from a reference product to a biosimilar. Emery et al. documented that safety and efficacy for the etanercept biosimilar SB4 was maintained for 100 weeks among patients who were switched to a biosimilar or for those who were on long-term maintenance therapy.

Then, the PLANETRA extension study also found similar efficacy and safety levels for patients who were switched from infliximab to the biosimilar CT-P13.

And, a study of adalimumab and the biosimiar SB5 and safety and efficacy were maintained after switching, but only for 52 weeks.

Still, it's too early to say that the biosimilars are interchangable, the authors wrote.

"Biosimilars are only considered interchangeable when it is shown that the risk of diminished safety and efficacy when switching is not greater than when the reference product is used alone. Additionally, FDA guidelines state that switching studies should evaluate switching between interchangeable medications two or more times. Further studies that include patients who have undergone two or more switching intervals are required," the authors wrote.

The authors noted some limitations to the study, including that it was limited to 100 weeks and only to Korean patients. Postmarketing surveillance of long-term use and other populations are needed, they wrote.

TAKE-HOME POINTS FOR CLINICIANS AND FINAL THOUGHTS

The improvements in DAS28-ESR, DAS28-CRP and ACR response rates seen in the first year of treatment with the biosimilar and reference product persisted up to another year in patients with rheumatoid arthritis even after switching.

Additionally, continued treatment with the biosimilar is associated with no more adverse events than seen in the original randomized study. Finally, there is no increase in immunogenicity with switching to or continuing with the biosimilar for the treatment of rheumatoid arthritis.

This is the second extension study this year to report persistent efficacy, safety and comparable immunogenicity between etanercept and a biosimilar. While some might wonder why more than one alternative biosimilar is needed, the answer lies in the primary reason for their development. With an increasing number of safe and effective options, patients with rheumatoid arthritis have more treatment choices at lower costs.

• For more news on etanercept from Rheumatology Network, click here.

• For more news on biosimilars, click here.

REFERENCE

Min-Chan Park, Hiroaki Matsuno, Jinseok Kim, 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.  Park et al. Arthritis Research & Therapy (2019) 21:122 https://doi.org/10.1186/s13075-019-1910-2