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Phase 2 Evaluation of Intravitreal Bevacizumab for DME. Sponsored by the National Eye Institute, National Institutes of Health, U.S. Department of Health and Human Services. Study Objectives.
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Phase 2 Evaluation of IntravitrealBevacizumab for DME Sponsored by the National Eye Institute, National Institutes of Health, U.S. Department of Health and Human Services.
Study Objectives • Assess the dose and dose interval related effects of intravitreal bevacizumab on central retinal thickness and VA in subjects with DME • Assess the effects of intravitreal bevacizumab combined with focal photocoagulation in DME • Assess the safety of intravitreal bevacizumab in subjects with DME
5 Treatment Groups Laser (0) Focal photocoagulation at baseline Bev 1.25 (0,6) 1.25 mg intravitreal bevacizumab at baseline and at 6 wks Bev 2.5 (0,6) 2.5 mg intravitreal bevacizumab at baseline and at 6 wks Bev 1.25 (0) 1.25 mg intravitreal bevacizumab at baseline with sham injection at 6 wks Bev 1.25 (0,6) + Laser (3) 1.25 mg intravitreal bevacizumab at baseline, focal photocoagulation at 3 wks, and 1.25 mg intravitreal bevacizumab at 6 wks
Efficacy Outcomes Central subfield thickness on OCT
Efficacy Outcomes Electronic-ETDRS Visual Acuity (EVA)
Study Phases • Weeks 0-12: no other treatment was to be given for DME in the study eye (study visits every 3 weeks) • Weeks 13-24: treatment depended on response to treatment given during the first 12 wks (study visits every 6 weeks) • After 24 weeks: follow-up for safety (study visits at 41 and at 70 weeks)
Study Results • Enrollment completed in 2 months • 121 eyes of 121 subjects randomized • 109 eyes included in efficacy analyses • Exclusions: • 5 baseline CSF <275 um • 1 nongradable baseline OCT • 1 hx of laser 3 mos prior to randomization • 2 CNV with diabetic retinopathy • 2 no follow-up • 1 endophthalmitis • 19-24 subjects in each group
Baseline Characteristics • Median age: 65 yrs • Women: 39% • Caucasian: 76% • Diabetes type: 1 – 7%, 2 – 93% • Median duration of diabetes: 17 yrs • No prior DME treatment: 31%
Baseline Characteristics • Visual Acuity Median (quartiles) letter score: 64 (71,56) approx. Snellen equivalent 20/50 (20/40,20/80) • Central Subfield Thickness Median (quartiles) microns : 411 (334, 505)
1. Does 1.25 mg bevacizumab have a positive effect on DME? • Compare Laser (0) vs. Bevacizumab 1.25 mg (0,6) at 3, 6, 9, and 12 weeks
OCT Central Subfield ThicknessMedian Change (microns) from Baseline
OCT Central Subfield Thickness <250 microns or >50% Decrease in Thickening
2. Does 2.5 mg bevacizumab have a positive effect on DME? • Compare Laser (0) vs. Bevacizumab 2.5 mg (0,6) at 3, 6, 9, and 12 weeks
OCT Central Subfield ThicknessMedian Change (microns) from Baseline
OCT Central Subfield Thickness <250 microns or >50% Decrease in Thickening
3. Does 2.5 mg bevacizumab produce a greater short-term reduction in DME than 1.25 mg? • Compare Bevacizumab 1.25 mg (0,6) vs. Bevacizumab 2.5 mg (0,6) at 3, 6, 9, and 12 weeks
OCT Central Subfield ThicknessMedian Change (microns) from Baseline
OCT Central Subfield Thickness <250 microns or >50% Decrease in Thickening
4. What is the duration of effect of the initial injection? • Among eyes with a decrease in CSF thickness of >11% (the reliability limit for real change) from baseline to 3 weeks, evaluate change from 3 weeks to 6 weeks
Duration of Initial Injection Pooling 1.25 mg Groups [Bev 1.25 (0,6) and Bev 1.25 (0)]
5. What is the duration of effect of the second injection? • Among eyes with a decrease in CSF thickness of at least 11% from 6w to 9w, evaluate change from 9 weeks to 12 weeks
6. Is there a greater effect with bevacizumab followed by focal laser compared with bevacizumab alone? • Compare (at 12 weeks) bevacizumab 1.25 mg alone vs. bevacizumab 1.25 mg plus laser
Effect of Combining Focal Photocoagulation with Bevacizumab at 12 Weeks
Subgroup Analyses at 3 Weekspooling all bevacizumab groups • Change in CSF thickness and change in VA from baseline to 3 weeks did not significantly vary according to: • Age, gender, baseline retinopathy severity, baseline clinical characterization of DME as focal or diffuse
Outcome during weeks 13-24 • Among eyes meeting deferral criteria at 12 weeks, deferral criteria were also met at 18 weeks in: • 2 of 4 eyes in Laser (0) Group • 5 of 7 eyes in Bev 1.25 (0,6) Group • 1 of 8 eyes in Bev 2.5 (0,6) Group • 2 of 3 eyes in Bev 1.25 (0) Group • 3 of 5 eyes in Bev 1.25 (0,6) + Laser (3) Group
Ocular Adverse Events • 1 eye in the Bev 1.25 (0,6) + Laser (3) Group with endophthalmitis
Cardiovascular Adverse Events • Fatal MI at 16 wks (1.25 inj at 0, 6 wks) • Non-fatal MI at 1 wk (2.5 inj at 0 wks) • CHF at 12 wks (1.25 inj at 0, 7 wks)
Other Systemic Adverse Events • Of the 107 subjects treated with bevacizumab • Death due to cancer (N=1) • Peripheral vascular disease (N=1) • Syncope (N=1) • Elevated BP (N=3) • Worsening renal function (N=3) • Anemia (N=4) • Of the 12 subjects receiving only focal photocoagulation • Peripheral vascular disease (N=2) • Elevated BP (N=1) • Worsening renal function (N=1) • Anemia (N=1)
Comparison of APTC events in Protocols H and B (IVT Study) • B: 11 of 693 (1.6%) subjects reported an APTC event over the first 24 weeks of follow-up • H: 2 of 107 (1.9%) subjects treated with bevacizumab reported an APTC event during the first 24 weeks of follow-up
Conclusions • There is an apparent effect of 1.25 mg and 2.5 mg of bevacizumab when compared with focal photocoagulation, although the effect appears to be modest • It does not appear that 2.5 mg of bevacizumab has an appreciably larger effect on DME than 1.25 mg
Conclusions • Injection intervals of 4 weeks are probably more appropriate than intervals of 6 weeks 4. A study arm with combination treatment (bevacizumab plus focal photocoagulation) is feasible from a logistical standpoint
Conclusions The study was designed to evaluate short term effect. No conclusions should be made regarding clinical benefit. A large phase 3 randomized clinical trial is needed for this purpose.