• Emixustat for Geographic Atrophy Secondary to AMD

    By Lynda Seminara
    Selected By: Stephen D. McLeod, MD

    Journal Highlights

    Ophthalmology, October 2018

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    Rosenfeld et al. evaluated the use of emixustat hydrochloride in the man­agement of geographic atrophy (GA). They found that emixustat did not re­duce the growth rate of GA—and that the most common adverse events were ocular in nature and likely attributable to the drug’s mechanism of action.

    Enrollees (N = 508) had GA secondary to age-related macular degenera­tion (AMD), total GA area ranging from 1.25 to 18 mm2, and a visual acuity score of at least 35 letters. Participants were assigned randomly (1:1:1:1) to receive placebo or emixustat (2.5, 5, or 10 mg) administered orally, once daily, for 24 months. Eval­uations were conducted from screen­ing through month 25. The primary efficacy endpoint was the mean annual growth rate of total GA area, which was measured from fundus autofluores­cence images at a central reading center. Also measured was the change from baseline in normal luminance best-cor­rected visual acuity (NL-BCVA). Safety and tolerability were determined by documenting adverse effects, measur­ing vital signs, and reviewing findings from lab tests and physical exams.

    The study was completed by 320 patients (63%). Demographics and baseline characteristics were com­parable among the 4 groups. During the study, average GA growth rates were similar with placebo and emix­ustat (placebo: 1.69 mm2 per year; emixustat groups: 1.69-1.84 mm2 per year). Changes in NL-BCVA also were comparable among the study groups. Subjects whose low luminance defi­cit (LLD) was larger at baseline (≥20 letters) had faster GA growth during the 24-month treatment period. No meaningful association was observed between GA growth rate and the risk-al­lele status of the AMD-associated single-nucleotide polymorphisms that were tested.

    The most common adverse events in patients treated with emixustat were delayed dark adaptation (55%), chromatopsia (18%), visual impairment (15%), and erythropsia (15%).

    The authors noted that this research sheds further light on the natural history of GA and confirms previously observed links between certain baseline traits and the rate of GA growth. Even though emixustat was not effective in their study, robust safety data were gained that may be relevant to other indications for emixustat.

    The original article can be found here.