Purpose:
A 2-year phase II proof-of-concept study was conducted to evaluate safety and efficacy of fenretinide in patients with geographic atrophy (GA). Prior pre-clinical data revealed potent anti-angiogenic and anti-inflammatory effects of fenretinide in animal models. These data led to the hypothesis that fenretinide would reduce the incidence of choroidal neovascularization (CNV) and would, therefore, reduce the risk of conversion from dry to wet AMD.
Methods:
Two hundred forty-six subjects enrolled at 30 sites in the US were randomized to fenretinide (100 mg or 300 mg) or placebo softgel capsules QD. All retinal images were collected and read by the Digital Angiography Reading Center (DARC, New York, NY). Efficacy outcomes included growth rate of the aggregate GA lesion area (measured by three different imaging modalities) and the rate of conversion to wet AMD as detected by fluorescein angiography. As part of the trial design, patients with active CNV in either the study or fellow eye, or a history of CNV in the study eye, were excluded from participation in the trial.
Results:
Among patients without CNV in the fellow eye, the occurance of new CNV (time to first CNV event in either the study or fellow eye) showed an incidence rate of ~19% in the placebo group. Meanwhile, CNV incidence in fenretinide arms was ~10% and was not dose-dependent. Calculated odds ratios showed a 2.2-fold increased risk of a CNV event in patients within the placebo group compared to patients in the combined fenretinide arms. Among patients who had CNV in the fellow eye at baseline, the incidence of CNV was 33% (2/6 patients) in placebo, 0% in the 100 mg fenretinide arm and 8% (1/13 patients) in the 300 mg fenretinide arm.
Conclusions:
Fenretinide reduced the incidence of emerging CNV, reducing the risk of progressing to wet AMD by ~2.2 fold. Experimental data indicate that this effect of fenretinide is due to its potent anti-angiogenic and anti-inflammatory properties. These data suggest that fenretinide may be useful to slow, or prevent, the conversion from dry to wet AMD and provide an impetus for design of formal Phase 3 studies to evaluate this therapeutic effect in a larger patient population.
Clinical Trial:
http://www.clinicaltrials.gov NCT00429936
Keywords: age-related macular degeneration • choroid: neovascularization • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials