Inflammation-Reducing Drug Shows No Benefit for Dry AMD in Trial

Key Takeaways

  • The drug minocycline, an antibiotic that also decreases inflammation, has previously shown beneficial effects for conditions such as diabetic retinopathy.
  • Minocycline failed to slow vision loss or expansion of geographic atrophy in people with dry age-related macular degeneration (AMD).

Dry AMD is an eye disease that affects the macula, the part of the eye’s retina that allows for clear central vision. In people with dry AMD, patches of light-sensing photoreceptors and their nearby support cells begin to die off, leaving regions known as geographic atrophy. Over time, these regions expand, causing people to lose more and more of their central vision. 

Microglia, immune cells that help maintain tissue and clear up debris, are present at higher levels around damaged retinal regions in people with dry AMD than in people without AMD. Scientists have suggested that inflammation—and particularly microglia—may be driving the expansion of geographic atrophy regions. Previous studies have shown that the antibiotic minocycline can help reduce inflammation and microglial activity in the eye, including the retina. The drug has shown beneficial effects for conditions such as diabetic retinopathy but has not previously been tested for dry AMD.

To test whether minocycline might help slow geographic atrophy expansion and its corresponding vision loss, Tiarnan Keenan, M.D., Ph.D., of the National Eye Institute’s Division of Epidemiology and Clinical Applications, and colleagues conducted a phase II clinical trial with 37 participants from the NIH Clinical Center in Bethesda, Maryland, and the Bristol Eye Hospital, United Kingdom. After a nine-month period where the researchers tracked each participant’s rate of geographic atrophy expansion, the participants took twice-daily doses of minocycline for two years. The researchers compared each participant’s rate of geographic atrophy expansion while taking minocycline to their baseline rate and found there was no difference in geographic atrophy expansion rate or vision loss with minocycline. The study was published in the journal JAMA Ophthalmology.

Source: National Institutes of Health, Medical Xpress, March 20, 2024; see source article