Study on Oral Minocycline for Geographic Atrophy in AMD

A recent study published in the Journal of American Medical Association investigated the potential of oral minocycline in slowing down the progression of geographic atrophy (GA) in age-related macular degeneration (AMD). GA is a leading cause of irreversible vision loss among the elderly, which makes effective treatments crucial.

Existing therapies for GA enlargement in AMD are limited in efficacy and often require invasive intravitreal administration, raising concerns about safety and patient compliance. Thus, Tiarnan Keenan and team evaluated the safety and efficacy of oral minocycline, a microglial inhibitor, as an alternative therapeutic approach.

The phase 2 clinical trial was conducted over 45 months and included 37 participants with GA in one or both eyes. After a 9-month run-in phase, the participants received oral minocycline (100 mg, twice daily) for 3 years. However, despite the treatment, this research found no significant reduction in the rate of GA enlargement when compared to the run-in phase.

The National Institutes of Health (NIH) and Bristol Eye Hospital expressed disappointment at the results by underlining that oral minocycline did not show the desired efficacy in slowing down GA progression. The difference in rate of change of GA area on fundus autofluorescence was the primary outcome measure, which remained largely unaffected by the treatment.

Also, secondary outcome measures included visual acuity and subfoveal retinal thickness, which showed no significant improvement with oral minocycline treatment. Despite some adverse events related to minocycline, like elevated thyrotropin levels and skin hyperpigmentation, no severe ocular complications were reported.

Reference

Keenan, T. D. L., Bailey, C., Abraham, M., Orndahl, C., Menezes, S., Bellur, S., Arunachalam, T., Kangale-Whitney, C., Srinivas, S., Karamat, A., Nittala, M., Cunningham, D., Jeffrey, B. G., Wiley, H. E., Thavikulwat, A. T., Sadda, S., Cukras, C. A., Chew, E. Y., & Wong, W. T. (2024). Phase 2 Trial Evaluating Minocycline for Geographic Atrophy in Age-Related Macular Degeneration. In JAMA Ophthalmology. American Medical Association (AMA). https://doi.org/10.1001/jamaophthalmol.2024.0118