Consistency of visual acuity response to anti-VEGF therapy in diabetic macular edema patients: An analysis of DRCRnet Protocol I data

Abstract

Purpose : Prompt, consistent, and long-lasting improvement in vision is an important goal in treating DME. Early identification of suboptimal responders to anti-VEGF therapy with little or inconsistent improvement in vision would facilitate timely consideration of additional or alternative treatments. This analysis assesses whether early BCVA response at 12 weeks can accurately predict consistent visual acuity improvement to ranibizumab over a 3-year study period.

Methods : A post-hoc analysis of PROTOCOL I data included diabetic macular edema patients randomized to ranibizumab + deferred or prompt laser with observed visual acuity at 12 weeks. Patients were stratified into 3 cohorts by best-corrected visual acuity (BCVA) at 12 weeks (<5 letters, 5-9 letters, and ≥10 letters improvement). Consistent improvement in BCVA was assessed by measuring the proportions of patients with ≥10 letters improvement from baseline at ≥50%, ≥75% and all but one of subsequent visits over the 3-year study. Differences in rates of consistent sub-optimal response of <5 letters improvement from baseline were also assessed.

Results : At 12 weeks, 340 patients met inclusion criteria; 135 (39.7%) patients had limited early response (<5 letters improvement), 79 (23.2%) patients had intermediate response (5-9 letters improvement), and 126 (37.1%) patients had strong early response (≥10 letters improvement). Subsequent rates of consistently good vision were significantly lower in patients with limited early response compared with a strong early response: 21.5% vs 81.0%, 11.1% vs 66.7%, and 0.7% vs 37.3% had BCVA improvement ≥10 letters at ≥50%, ≥75%, and all but one visit after week 12 (p<0.001 for all comparisons, Table 1). Likewise, limited early responders were significantly more likely to see continued consistent sub-optimal response over the three year study, compared with intermediate and strong early responders (p<0.001 for all comparisons, Table 1).

Conclusions : Patients with limited BCVA response at 12 weeks continue to have suboptimal and inconsistent improvements in BCVA to ranibizumab over the 3-year duration of the study. These findings support early consideration of additional or alternative therapies in patients with suboptimal early response to maximize potential vision benefit.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Table 1: Proportion of visits with Consistent Strong Response and Sub-optimal Response