A simulated switching study assessed the effects of continuing the same anti–vascular endothelial growth factor (VEGF) treatment among patients who typically are considered for a therapy switch. Post hoc analysis of data from HARBOR was undertaken. Patients with neovascular age-related macular degeneration who demonstrated a suboptimal response after 3 or 6 months of ranibizumab treatment were identified as switching candidates. Rather than switching, however, patients continued on ranibizumab treatment, and visual and anatomic outcomes from the point of the hypothetical switch were examined.

Post hoc analysis of the phase 3 HARBOR clinical trial.

Patients were included in 3- and 6-month switcher analyses if they received 3 of 3 initial monthly ranibizumab doses and 5 of 6 initial monthly ranibizumab doses, respectively, and met all the following: 5-letter or fewer gain from baseline, best-corrected visual acuity (BCVA) 20/40 or worse, and intraretinal or subretinal fluid with central foveal thickness (CFT) equal to or greater than central subfield thickness.

Patient data were examined at months 3 and 6 to identify those who met predetermined switching criteria. Best-corrected visual acuity and CFT were examined from the point at which switching criteria were met through months 6, 12, 18, and 24 of HARBOR and compared with those who did not meet the criteria.

Outcome measures included mean BCVA and CFT change over time from the point (month 3 or 6) at which switching criteria were met.

By months 3 and 6, only 44 of 1059 patients (4.2%) and 37 of 769 patients (4.8%), respectively, met the inclusion criteria for hypothetical switching. Patients who met switching criteria at month 3 gained, on average, 5.3 letters from months 3 to 12 and 2.7 letters from months 3 to 24. Month 6 switchers gained, on average, 1.6 letters from months 6 to 12 and 1.8 letters from months 6 to 24. Both groups experienced significant CFT reductions over 24 months.

Month 3 hypothetical switchers achieved vision and anatomic improvement while continuing their original ranibizumab treatment. Month 6 switcher outcomes replicated those commonly reported in published anti-VEGF switching studies: stable vision or nominal improvements in vision with continued substantial anatomic improvement.