Post-hoc Analysis Confirms Biosimilarity Between SB15, Reference Aflibercept

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A switch to SB15, a proposed biosimilar to aflibercept (Eylea), from the reference product maintained comparable efficacy and safety in patients with neovascular age-related macular degeneration (nAMD), according to a new posthoc analysis.¹

Presented at EURETINA 2023 in Amsterdam, the Netherlands, the results confirmed biosimilarity between SB15 and reference aflibercept before and after the switching period.

“This posthoc analysis provides valuable insights on the outcomes of switches from the reference biologic to SB15 and may help clinicians to make well-informed decisions on the potential use of SB15 if approved,” said Mourad Farouk Rezk, vice president and head of global medical and development, Biogen Biosimilars Unit, in a statement.

The phase 3, randomized, double-masked, parallel-group, multicenter study included 449 participants, randomized 1:1 to receive 3 initial monthly 0.05 mL intravitreal injections of either 2 mg SB15 or reference aflibercept, followed by treatment once every 8 weeks up to 48 weeks. The analysis’ goal was to determine biosimilarity between SB15 and the reference product.

The study’s primary endpoint was the change from baseline in best-corrected visual acuity (BCVA) at week 8, and all endpoints were followed through week 56. Efficacy and safety after switching were compared to results prior to switching. The post-hoc analysis was conducted on efficacy endpoints, including the change in BCVA and central subfield thickness (CST).

Data were measured at the time of re-randomization at week 32 prior to injection as the new baseline to compare clinical biosimilarity between SB15 and aflibercept post-switching: aflibercept to SB15 group versus aflibercept-only group. At week 32, a total of 438 participants were re-randomized, including 219 continuing SB15 treatment, 108 continuing aflibercept, and 11 switching from aflibercept to SB15. Overall, 425 (97.0%) re-randomized participants completed the study up to week 56.

New baseline characteristics were considered comparable between the continued aflibercept treatment group and the aflibercept to SB15 group. Efficacy was considered well-maintained post-switching as the mean BCVA letter score was 65.3 (Snellen equivalent, 20/50) at week 32 and 65.8 (Snellen equivalent, 20/50) at Week 56 for the aflibercept to SB15 group. For the continued aflibercept group, the mean BCVA letter score was 65.2 (Snellen equivalent, 20/50) at week 32 and 65.8 (Snellen equivalent, 20/50) at week 56.

In addition, there were no differences in efficacy between the groups post-switching, with a least-square mean change in BCVA from week 32 to 56 was 0.0 letters for the aflibercept maintained group and 0.2 letters for the aflibercept to SB15 group (difference, 0.3 [95% CI, –1.2 to 1.8] letters). The least-squares mean change in CST from week 32 to 56 was –13µm for aflibercept continued group and –9µm for the aflibercept to SB15 group (difference, 4 [95% CI, –7 to 14] µm). No additional safety signals were identified, with a similar immunogenicity profile after switching.

“We are pleased to present the switching data of SB15 from reference aflibercept that continues to demonstrate its comparable clinical efficacy and safety in treating patients with nAMD,” said Hyejin Kim, vice president and medical and lifecycle safety team leader at Samsung Bioepis, in a statement. “We hope the study results also help allay concerns over safety and efficacy of biosimilars for their use in patients who were previously treated with reference product,”

References

1. Srinivas R Sadda, Se Joon Woo, et al. Pre-to-Post Switching Efficacy and Safety Assessments of SB15 (Proposed Aflibercept Biosimilar) in Neovascular Age-Related Macular Degeneration: Findings from a Post-hoc Analysis of a Phase III Clinical Trial. Presentation Presented at EURETINA 2023
2. Samsung Bioepis Presents Post-hoc Analysis of Phase 3 Clinical Trial for SB15, a Proposed Biosimilar to Eylea (Aflibercept), at EURETINA 2023. October 7, 2023. Accessed October 24, 2023. https://www.samsungbioepis.com/en/newsroom/newsroomView.do?idx=352&currentPage=1.