Efficacy of SB15 Comparable to Reference Aflibercept, Study Finds

Min Sagong, MD, PhD
Credit: LinkedIn

New research indicates the comparable efficacy between SB15, an aflibercept biosimilar, and the reference product, was well-maintained for up to 1 year in patients with neovascular age-related macular degeneration (nAMD).¹

The findings, presented at the American Society of Retina Specialists (ASRS) 41st Annual Meeting, showed the characteristics of adverse events in eyes treated with SB15 were comparable to and in line with the known safety profile of reference aflibercept.

“All of the efficacy and safety were well-maintained in the switching group without treatment-emergent issues, indicating that switching from aflibercept to SB15 is as effective and safety as continuing the reference aflibercept,” Min Sagong, MD, PhD, a professor at Yeungnam University College of Medicine, said in the presentation at ASRS 2023.

SB15 is a proposed biosimilar of reference aflibercept. The development of biosimilars follows the totality of evidence approach, which consists of analytical studies, animal studies, and clinical studies to demonstrate no clinically meaningful differences in safety, purity, and potency in ≥1 more appropriate condition of use for the reference product.

Increasing evidence suggests that switching from reference products to biosimilars is as safe and effective as continuing reference products in other therapeutic areas. However, there is insufficient information on switching to ophthalmic anti-VEGF biosimilars.

Investigators conducted a phase 3, randomized, double-masked, multicenter clinical trial at 56 sites across 10 countries. The trial aimed to demonstrate the comparable clinical efficacy, safety, immunogenicity, and pharmacokinetics (PK) of SB15 to aflibercept in patients with nAMD up to Week 56. Investigators additionally assessed the clinical effect of switching from aflibercept to SB15.

The primary study endpoint was the change in baseline best-corrected visual acuity (BCVA) at Week 8, considered the most sensitive time point to demonstrate biosimilarity. The equivalency in efficacy observed as the primary endpoint was met and comparable efficacy, safety, immunogenicity, and PK results up to 32 weeks were reported previously.² In the current analysis, investigators reported the 1-year outcomes of the phase 3 comparative study.

Patients were randomized 1:1 to either 2mg SB15 or aflibercept at Week 0. At Week 32, patients were re-randomized to either continuing SB15 or aflibercept or switching from aflibercept to SB15. It used a fixed-dosing regimen at once every 4 weeks for the first 3 injections, then once every 8 weeks up to Week 48.

The key efficacy endpoints were the change in BCVA through Week 56, the change from baseline in CST through Week 56, and the proportion of patients with intra- or sub-retinal fluid at Week 56. Safety, immunogenicity, and PK endpoints were assessed until Week 56. Of 449 patients included in the study, 425 (94.7%) completed Week 56 of the study, and baseline demographics were considered generally well-balanced.

Upon analysis, investigators found the mean change from baseline in BCVA was comparable at each visit up to Week 56 across all treatment groups. Moreover, after week 32, in the switching group, the mean change from baseline in BCVA was well-maintained and comparable to those who continued aflibercept treatment (least-squares mean BCVA letter change, 7.3 for SB15 vs 6.4 for AFL; 7.9 for AFL/SB15 vs 7.5 for AFL/AFL).

Anatomical outcomes were comparable across all treatment groups up to Week 56. After Week 32, in the switching group, the analysis showed the least-squares mean change from baseline in CST was well-maintained and comparable to the continuing group.

The analysis showed safety profiles in SB15 were comparable to aflibercept before and after switching. There were no new or unexpected adverse events during the study and the safety findings of SB15 were consistent with the known safety profiles of reference aflibercept. No cases of intraocular inflammation or endophthalmitis were observed in the SB15 group.

Regarding immunogenicity, the Incidence of anti-drug antibodies was low and comparable between SB15 and aflibercept up to Week 56. There were additionally no treatment-induced or-boosted anti-drug antibodies in the switching group reported in the analysis.

“Immunogenicity and pharmacokinetics profiles of SB15 were also similar to those of reference aflibercept,” Sagong said.

References

1. Sagong M, Sadda SR, Woo SJ, Bradvica M, Vajas A, Ernest J, Studnicka J, Veith M, Wylegala E, Patel S, Yun C, Orski M, Astakhov, Toth-Molnar E, Csutak A, Enyedi L, Kim T, Oh I, Jang H. Phase III Randomized Clinical Trial Comparing SB15 with Reference Aflibercept in Neovascular Age-Related Macular Degeneration. Paper presentation at the American Society of Retina Specialists 41st Annual Meeting. July 28 - August 1.
2. Iapoce, C. (2022) Biosimilar SB15 indicates equivalent efficacy to aflibercept in NAMD treatment, HCP Live. Available at: https://www.hcplive.com/view/biosimilar-sb15-indicates-equivalent-efficacy-aflibercept-namd (Accessed: 15 August 2023).