Abstract
IMPORTANCE: SB11 and reference ranibizumab (RBZ) are monoclonal anti-vascular endothelial growth factor (VEGF)-A antibodies approved for the treatment of neovascular age-related macular degeneration (nAMD) and other retinal diseases. The association of ranibizumab immunogenicity and treatment outcomes in patients with nAMD is unclear but relevant regarding concerns about immunogenicity of anti-VEGF biological products. OBJECTIVE: To examine the association of immunogenicity to ranibizumab products (SB11 and RBZ) with efficacy, safety, and pharmacokinetics. DESIGN, SETTING, AND PARTICIPANTS: This was a post hoc analysis of a randomized, double-masked, parallel-group phase 3 equivalence study with participants from 75 centers in 9 countries conducted from March 14, 2018, to December 9, 2019. Included were participants 50 years or older with nAMD and active subfoveal choroidal neovascularization lesions. INTERVENTIONS: Intravitreal injection of SB11 or RBZ, 0.5 mg, every 4 weeks through week 48. MAIN OUTCOMES AND MEASURES: Serum antidrug antibodies (ADAs) were analyzed during the study period until week 52 to measure immunogenicity. Analyses were performed on immunogenicity (overall ADA positivity) with best-corrected visual acuity (BCVA) and central subfield thickness (CST). Adverse events associated with intraocular inflammation (IOI) and serum ranibizumab levels were compared between overall ADA-positive and ADA-negative participants. RESULTS: A total of 705 participants (mean [SD] age, 74.1 [8.5] years; 403 female individuals [57.2%]) were included in the study. The overall incidence of ADA-positivity was 32 of 657 (4.9%) at week 52. The least-squares mean (SE) differences between overall ADA-positive and ADA-negative participants up to week 52 for BCVA and CST, respectively, were 1.6 (2.2) letters (95% CI, -2.7 to 5.8; P = .46) and 3 (13) μm (95% CI, -23 to 29; P = .83). IOI-related events occurred in 1 of 32 overall ADA-positive participants (3.1%) and 4 of 620 overall ADA-negative participants (0.6%). Mean (SD) serum ranibizumab concentrations over time were slightly lower in overall ADA-positive participants compared with those of ADA-negative participants, with a maximum value of 1389.3 (875.4) pg/mL at week 16 vs 1665.4 (1124.0) pg/mL at week 36, respectively. CONCLUSIONS AND RELEVANCE: Results of this post hoc analysis of an equivalence trial suggest that immunogenicity was not associated with efficacy and safety of SB11 and RBZ in participants with nAMD. With a low overall ADA incidence, no clear association was identified between overall ADA positivity and pharmacokinetics. These findings support the biosimilarity of SB11 and RBZ, with no safety concern identified for SB11 vs RBZ associated with immunogenicity. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03150589.