A Phase 2 Randomized Clinical Trial of Intravitreal Bevacizumab for Diabetic Macular Edema Diabetic Retinopathy Clinical Research Network

Objective—To provide data on the short-term effect of intravitreal bevacizumab for diabetic macular edema (DME). Design—Randomized phase 2 clinical trial. Participants—121 eyes of 121 subjects (109 eligible for analysis) with DME and Snellen acuity equivalent ranging from 20/32-20/320. Interventions—Random assignment to one of five groups: focal photocoagulation at baseline (N=19, Group A), intravitreal injection of 1.25mg bevacizumab at baseline and 6 weeks (N=22, Group B), intravitreal injection of 2.5mg bevacizumab at baseline and 6 weeks (N=24, Group C), intravitreal injection of 1.25mg bevacizumab at baseline and sham injection at 6 weeks (N=22, Group D), or intravitreal injection of 1.25mg bevacizumab at baseline and 6 weeks with photocoagulation at 3 weeks (N=22, Group E). Main Outcome Measures—Central subfield thickness (CST) on optical coherence tomography and best-corrected visual acuity (VA) were measured at baseline and after 3, 6, 9, 12, 18, and 24 weeks. Results—At baseline, median CST was 411 microns and median Snellen VA equivalent was 20/50. Compared with Group A, Groups B and C had a greater reduction in CST at 3 weeks and about one line better median visual acuity over 12 weeks. There were no meaningful differences between Groups B and C in CST reduction or VA improvement. A CST reduction >11% (the reliability limit) was present at 3 weeks in 36/84 (43%) bevacizumab-treated eyes and in 5/18 (28%) eyes treated with laser alone, and at 6 weeks in 31/84 (37%) and 9/18 (50%) eyes, respectively. Combining focal photocoagulation with bevacizumab resulted in no apparent short-term benefit or adverse outcomes. Endophthalmitis developed in one eye. The following events occurred during the first 24 weeks in subjects treated with bevacizumab without attributing cause to the drug: myocardial infarction (N=2), congestive heart failure (N=1), elevated blood pressure (N=3), and worsened renal function (N=3). Conclusion—These results demonstrate that intravitreal bevacizumab can reduce DME in some eyes, but the study was not designed to determine whether treatment is beneficial. A phase 3 trial would be needed for that purpose.