Switching to Biosimilar Etanercept Is Safe and Effective in RA

As more biosimilars are earning regulatory approvals in both the United States and the European Union, the question of whether to switch patients (and at what point to do so) continues to be discussed; researchers will present findings from 2 etanercept switching studies in patients with rheumatoid arthritis (RA) during the American College of Rheumatology’s (ACRs) Annual meeting, held in Chicago, Illinois October 19-24, 2018.

The first study¹, a single-center retrospective observational study, analyzed findings from when patients with RA were switched from the reference Enbrel to the biosimilar sold as Benepali at Blackpool Teaching Hospitals located in the United Kingdom. The review included all patients switched from July 2016 to April 2018.

In total, 72 patients were switched to the biosimilar, of whom 19 (26.4%) switched back to the reference product after 6 months. All 19 of these patients remained on the reference product until the time of data analysis, which was a follow up period of 12 months.

Researchers found that the reasons for withdrawal were loss of efficacy (58%), adverse events (AEs) (32%), infection (5%) and difficulty using the device to administer the medication (5%). However, the majority of patients that who switched to the biosimilar had a good response (73.6%), which the authors note is in keeping with the current evidence.

In another switching study², researchers compared the efficacy and safety of a proposed etanercept biosimilar, GP2015, with the reference product and evaluated the effects of switching from the reference to the biosimilar in patients with moderate to severe RA.

EQUIRA, a 48-week, randomized, double-blind, phase 3 confirmatory study had a primary endpoint of equivalent change from baseline as measured by disease activity score in a count of 28 joints with C-reactive protein (DAS28-CRP) at week 24. Patients 18 years or older with active RA who had an inadequate response to methotrexate were randomized 1:1 to receive 50 mg of GP2015 or the reference product subcutaneously once-weekly for 24 weeks.

The study enrolled 186 patients to the GP2015 arm, and 190 patients to the reference arm. Baseline characteristics were comparable between the groups, and the primary endpoint for equivalence during the first 24 weeks (defined as treatment period 1) was met. Additionally, at week 48, the American College of Rheumatology 20% improvement (ACR20) response rates were comparable between patients who continued on or switched to the biosimilar.

At week 24, patients with moderate European League Against Rheumatism (EULAR) response either continued the biosimilar or were switched to receive 50 mg of GP2015 for up to 48 weeks. During this time period (defined as treatment period 2) AEs occurred in 42.9% of patients in the biosimilar arm versus 38% of patients in the reference arm, respectively; however, only 13.1% versus 11.4% were considered drug-related.

Overall, the efficacy of GP2015 over 48 weeks was found to be comparable to that of the reference product. The researchers also noted that the switch from the reference to the biosimilar did not impact the efficacy or safety of etanercept treatment in patients with moderate to severe RA.

References

1. Madenidou AV, Jeffries A, Varughese S, et al. Switching patients with arthritis from etanercept (Enbrel) to the biosimilar drug, Benepali: a single-center retrospective observational study. Presented at the American College of Rheumatology 2018 meeting, October 19-24, 2018; Chicago, Illinois. Abstract 2533. https://acrabstracts.org/abstract/switching-patients-with-arthritis-from-etanercept-enbrel-to-the-biosimilar-drug-benepali-a-single-center-retrospective-observational-study/.

2. Kavanaugh A, Mattucci-Cerini M, Schulze-Koop H, et al. Phase 3 Equirea 48-week study results demonstrated no impact on efficacy and safety when patients with moderate-to-severe rheumatoid arthritis were switched between reference etanercept (ETN) and GP2015, an etanercept biosimlar. Presented at the American College of Rheumatology 2018 meeting, October 19-24, 2018; Chicago, Illinois. Abstract 2250. https://acrabstracts.org/abstract/phase-3-equira-48-week-study-results-demonstrated-no-impact-on-efficacy-and-safety-when-patients-with-moderate-to-severe-rheumatoid-arthritis-were-switched-between-reference-etanercept-etn-and-gp201/.