Vision loss reduction with avacincaptad pegol for geographic atrophy: a 12-month post hoc analysis of the GATHER1 and GATHER2 trials

Purpose To evaluate the impact of reduction in geographic atrophy (GA) lesion growth on visual acuity in the GATHER trials using categorical outcome measures. Design Randomized, double-masked, sham-controlled phase 3 trials. Participants Aged ≥50 years with non-center point involving GA and best corrected visual acuity (BCVA) of 25-80 Early Treatment Diabetic Retinopathy Study (ETDRS) letters in the study eye. Methods GATHER1 consisted of 2 parts. In Part 1, 77 patients were randomized 1:1:1 to avacincaptad pegol (ACP) 1 mg, ACP 2 mg, and sham. In Part 2, 209 patients were randomized 1:2:2 to ACP 2 mg, ACP 4 mg, and sham. In GATHER2, patients were randomized 1:1 to ACP 2 mg (n=225) and sham (n=223). A post hoc analysis of 12-month data for pooled ACP 2 mg and sham groups is reported. Main Outcome Measures Proportion of study eyes that experienced ≥10-, ≥15-, or ≥20-BCVA ETDRS letter loss from baseline to month 12; time-to-event analysis of persistent vision loss of ≥10-, ≥15-, or ≥20-BCVA letters from baseline at ≥2 consecutive visits over 12 months; proportion of study eyes with BCVA loss to a level below driving eligibility threshold at month 12 among those eligible to drive at baseline. Results Lower proportions of study eyes experienced ≥10-, ≥15-, or ≥20-BCVA letter loss from baseline over 12 months with ACP 2 mg (11.6%, 4.0%, and 1.6%, respectively) vs sham (14.1%, 7.6%, and 4.5%, respectively). There was a reduction in the risk of persistent loss of ≥15-BCVA ETDRS letters with ACP 2 mg (3.4%) vs sham (7.8%) through 12 months. A lower proportion of study eyes treated with ACP 2 mg reached the threshold for driving ineligibility vs sham by 12 months. Conclusions Treatment with ACP 2 mg delayed the risk of progression to persistent vision loss (ie, ≥10-, ≥15-, and ≥20-BCVA letter loss or BCVA loss to a level below driving eligibility threshold) vs sham over 12 months.