Research Focuses on Etanercept Biosimilar SB4, Treatment Retention, and Disease Activity

As biosimilar etanercept SB4, sold in many markets as Benepali, has entered the rheumatoid arthritis (RA) treatment space, researchers have recognized the need to investigate the retention rates and disease activity scores among patients receiving SB4 and its reference product.

In a study¹ presented at the American College of Rheumatology’s (ACRs) Annual Meeting in Chicago, Illinois, researchers will report on their study that compared treatment survival on etanercept biosimilar SB4 with treatment survival on the reference product using real-world data.

Data were collected from 2015-2018 from patients with RA who began treatment with SB4 or the reference product and who had at least 1 followup visit. Drug survival rates during the first 6 months were analyzed using Kaplan-Meier curves.

In total, 266 patients were treated with SB4 compared with 313 patients administered the reference product. Researchers found that those taking SB4 had a shorter disease duration (7.5 years versus 8.7 years, respectively) and were younger (58 years of age versus 59 years of age, respectively). Fewer patients taking SB4 than the reference had 3 or more comorbidities (39% versus 47%, respectively). In addition, the Kaplan-Meier curves showed higher retention rates over 6 months for SB4 than the reference.

The most frequent reasons for discontinuation of either treatment were adverse events (48% in the SB4 arm and 54% in the reference arm) and ineffectiveness (36% of the SB4 arm and 36% of the reference arm).

The study’s authors concluded that higher retention rates were identified for patients starting biosimilar SB4 compared with those beginning with the originator product.

A second study addressing SB4² that will be presented the meeting evaluated patients’ disease activity after switching from the originator etanercept to SB4. The study was conducted retrospectively across hospitals in Wales, United Kingdom.

To evaluate the disease activity before and after switching, investigators used the disease activity score in a count of 28 joints (DAS28) with C-reactive protein (CRP). The study found that after switching to the biosimilar, 39% of patients had an increase in their DAS28-CRP score.

Out of 102 patients who were in remission at the time of switching, 17% developed low, moderate, or high disease activity. At baseline, 18 patients had low or moderate disease activity, and 56% of this group moved to moderate or high disease activity.

Overall, the researchers noted that, while many patients enrolled in the study saw an increase in disease activity, it was deemed likely that these patients were not truly in disease remission at the time of switching. This finding suggests that the increase may be due to natural fluctuation or spontaneous disease flare in patients with unstable disease.

References

1. Baganz L, Meißner Y, Herzer P, et al. Treatment continuation on the etanercept original in comparison with a biosimilar. Presented at the American College of Rheumatology 2018 meeting, October 19-24, 2018; Chicago, Illinois. Abstract 2512. https://acrabstracts.org/abstract/treatment-continuation-on-the-etanercept-original-in-comparison-with-a-biosimilar/.

2. Rajamani K, Choy E. Change in disease activity after switching etanercept (originator) to biosimilar (Benepali) is associated with active disease at baseline. Presented at the American College of Rheumatology 2018 meeting, October 19-24, 2018; Chicago, Illinois. Abstract 2513. https://acrabstracts.org/abstract/change-in-disease-activity-after-switching-etanercept-originator-to-biosimilar-benepali-is-associated-with-active-disease-at-baseline/.