Treatment of Geographic Atrophy with Intravitreal Sirolimus: The Age-Related Eye Disease Study 2 Ancillary Study.
Objective/Purpose: To evaluate efficacy and safety of monthly intravitreal injections of sirolimus, an immunosuppressive drug, for the treatment of age-related macular degeneration associated geographic atrophy (GA).
Design: Randomized, controlled, single-masked multi-center phase 2 clinical trial of intravitreal sirolimus vs. sham therapy in AREDS2 clinical centers.
Subjects: Participants with GA.
Methods: Participants eligible in one eye were randomly assigned to a monthly intravitreal injection of sirolimus (20 µL [440 µg]) or sham treatment while participants with two study eyes were assigned to a monthly intravitreal injection in a randomly-selected eye. Best-corrected visual acuities (BVCA), spectral domain optical coherence tomography (OCT), fundus color photography and fundus autofluorescence (FAF) images were obtained at baseline and every 6 months until visit month 24.
Main Outcome Measures: Rate of progression of GA (mm/year) measured on color fundus photograph from baseline to 24 months. Secondary outcome measures include change in BVCA, worsening of vision by ≥3 lines, and changes in area of GA measured on FAF and OCT.
Results: 52 participants (mean age 79 years) were enrolled with 27 study eyes assigned to sirolimus from May 2012 to March 2014. The baseline median area of GA was 4.73 DA (12.01 mm). The mean (standard deviation) growth rates of GA detected on color fundus photographs were 2.27 (2.17) mm and 1.91 (2.27) mm at month 12, and 4.94 (2.96) mm and 5.72 (3.97) mm at month 24, for the sirolimus and sham groups, respectively. There was no statistically significant difference in the GA growth rates between the two treatment groups (P=0.33). Median visual acuity changes and incidence of 15-letter loss from baseline were not different between the 2 treatment groups (p=0.19). The intervention was stopped early because of sterile endophthalmitis that occurred in 3 participants in the sirolimus group. Participants were followed for safety until the study was closed in May 2015 due to lack of efficacy.
Conclusion: Sirolimus did not result in different rates of GA growth in this phase 2 study. Immunosuppression may be important for some stages of the AMD process but may not necessarily be the main pathway for the development of GA.