fenretinide and Geographic-Atrophy

Age-related macular degeneration (AMD) is a highly prevalent condition in an ever-increasing elderly population. Although insidious in the early stages, advanced AMD (neovascular and atrophic forms) can cause significant visual disability and economic burden on health systems worldwide. The most common form, geographic atrophy, has no effective treatment to date, whereas neovascular AMD can be treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections. Geographic atrophy has a slow disease progression and patients tend to have preserved central vision until the final stages. This tendency, coupled with the use of modern imaging modalities, provides a large window of opportunity to intervene with validated methods to assess treatment efficacy. As geographic atrophy is an increasingly common condition with no effective intervention, many treatments are under investigation, one of which is visual cycle modulators. These medications have been shown to reduce lipofuscin accumulation in pre-clinical studies that have led to several clinical trials, reviewed herein.. To assess the efficacy and safety of visual cycle modulators for the prevention and treatment of geographic atrophy secondary to AMD.. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2020, Issue 1); MEDLINE Ovid; Embase Ovid; Web of Science Core Collection; Scopus; Association for Research in Vision and Ophthalmology (ARVO) website; ClinicalTrials.gov and the WHO ICTRP to 11 January 2020 with no language restrictions. We also searched using the reference lists of reviews and existing studies and the Cited Reference Search function in Web of Science to identify further relevant studies.. We included randomised controlled trials (RCTs) and quasi-randomised clinical studies (if available) that compared visual cycle modulators to placebo or no treatment (observation) in people diagnosed with AMD (early, intermediate or geographic atrophy).. Two authors independently assessed risk of bias in the included studies and extracted data. Both authors entered data into RevMan 5. We resolved discrepancies through discussion. We graded the certainty of the evidence using the GRADE approach.. There is limited evidence to support the use of visual cycle modulators (emixustat and fenretinide) for the treatment of established geographic atrophy due to AMD. The possible reduction in the incidence of CNV observed with fenretinide, and to a lesser extent, emixustat, requires formal assessment in focused studies.

Topics: Aged; Aged, 80 and over; Choroidal Neovascularization; Clinical Trials, Phase II as Topic; Disease Progression; Fenretinide; Geographic Atrophy; Humans; Incidence; Macular Degeneration; Phenyl Ethers; Placebos; Propanolamines; Randomized Controlled Trials as Topic; Visual Acuity; Watchful Waiting

Geographic atrophy, the dry form and late manifestation of age-related macular degeneration, is the next challenge following the breakthrough in the treatment of neovascular age-related macular degeneration (AMD). Various interventional pharmacologic approaches with different targets are already being tested in clinical interventional trials. These include reduction of retinal toxins, anti-inflammatory agents, complement inhibition, neuroprotection and alleviation of oxidative stress. Until efficacy and safety is demonstrated, aids for poor vision and further rehabilitative measures remain essential for patients with advanced dry AMD.

Topics: Aged; Anti-Inflammatory Agents; Antineoplastic Agents; Carrier Proteins; cis-trans-Isomerases; Clinical Trials as Topic; Complement Inactivating Agents; Eye Proteins; Fenretinide; Geographic Atrophy; Humans; Neuroprotective Agents; Oxidative Stress; Receptor, Serotonin, 5-HT1A; Serotonin Receptor Agonists; Vision Tests; Vitamin A

Excessive accumulation of retinol-based toxins has been implicated in the pathogenesis of geographic atrophy (GA). Fenretinide, an orally available drug that reduces retinol delivery to the eye through antagonism of serum retinol-binding protein (RBP), was used in a 2-year trial to determine whether retinol reduction would be effective in the management of geographic atrophy.. The efficacy of fenretinide (100 and 300 mg daily, orally) to slow lesion growth in geographic atrophy patients was examined in a 2-year, placebo-controlled double-masked trial that enrolled 246 patients at 30 clinical sites in the United States.. Fenretinide treatment produced dose-dependent reversible reductions in serum RBP-retinol that were associated with trends in reduced lesion growth rates. Patients in the 300 mg group who achieved serum retinol levels of ≤ 1 μM (≤ 2 mg/dL RBP) showed a mean reduction of 0.33 mm in the yearly lesion growth rate compared with subjects in the placebo group (1.70 mm/year vs. 2.03 mm/year, respectively, P = 0.1848). Retinol-binding protein reductions <2 mg/dL correlated with further reductions in lesion growth rates (r = 0.478). Fenretinide treatment also reduced the incidence of choroidal neovascularization (approximately 45% reduction in incidence rate in the combined fenretinide groups vs. placebo, P = 0.0606). This therapeutic effect was not dose dependent and is consistent with anti-angiogenic properties of fenretinide, which have been observed in other disease states.. The findings of this study and the established safety profile of fenretinide in chronic dosing regimens warrant further study of fenretinide in the treatment of geographic atrophy.

Topics: Administration, Oral; Aged; Aged, 80 and over; Antineoplastic Agents; Contrast Sensitivity; Dose-Response Relationship, Drug; Double-Blind Method; Female; Fenretinide; Geographic Atrophy; Humans; Male; Middle Aged; Retinol-Binding Proteins, Plasma; Surveys and Questionnaires; Treatment Outcome; Visual Acuity; Vitamin A