Oral minocycline flops for geographic atrophy in AMD

Treatment with oral minocycline falls short of slowing the rate of geographic atrophy (GA) enlargement in patients with age-related macular degeneration (AMD), according to the results of a phase II study.

A total of 37 patients (mean age 74.3 years, 57 percent female) with GA from AMD in one or both eyes were recruited for the study. Of these patients, 36 initiated treatment with oral minocycline 100 mg after a 9-month run-in phase. Treatment was administered twice daily for 3 years.

The primary outcome was the difference in rate of change of square root GA area, as measured through fundus autofluorescence, between the 9-month run-in phase and the 24-month treatment phase. A total of 21 patients (58 percent) completed at least 33 months of treatment, whereas 15 discontinued treatment (eight by request, six due to adverse events/illness, and one had died).

Mean square root GA enlargement rate in study eyes did not significantly differ between the run-in phase and the treatment phase (0.31 vs 0.28 mm per year; mean difference, −0.03 mm per year; p=0.39).

Results for the secondary outcome measures likewise showed no between-group differences. The mean difference in rate of change of visual acuity between the run-in and the treatment phases was 0.2 letter score per month (95 percent confidence interval [CI], −0.4 to 0.9; p=0.44), while that of subfoveal retinal thickness was 0.7 μm per month (95 percent CI, −0.4 to 1.8; p=0.20).

As for safety, 129 treatment-emergent adverse events (TEAEs) were documented among 32 participants. Of these TEAEs, 49 (38 percent) were related to minocycline (with no severe or ocular events), including elevated thyrotropin level (n=15) and skin hyperpigmentation/discoloration (n=8).