The primary endpoint was the change from baseline in size of GA lesion area at month 12. Compared with the control group, GA progression rate was reduced 18.8% and 27.5% in the low-dose and high-dose Brimo DDS groups, respectively, at month 12.
Although the study was not powered to detect statistically significant differences, analyses of additional time points showed that the rate of GA lesion growth was significantly lowered in both Brimo DDS groups compared with the control arm at month 3.
“A post-hoc sensitivity analysis of the square root of GA lesion area using observed data (i.e., without imputation) was also performed,” reported Dr. Freeman. “This analysis confirmed that mean GA area growth was consistently lower in both Brimo DDS treatment groups throughout the follow-up.”
The difference compared with sham in both Brimo DDS treatment groups increased over time, and approached statistical significance at month 24 for the comparison between the brimonidine high-dose group and sham controls (P<0.059).
The only adverse events reported in the study were events attributed to the intravitreal injection. They included conjunctival hemorrhage, conjunctival redness, and floaters. Intraocular pressure was not changed, which was expected because brimonidine is eliminated through the retina rather than through the front of the eye, Dr. Freeman said.
Known as BEACON, the ongoing study of intravitreal brimonidine as a cyto/neuroprotective agent for GA is investigating generation 2 Brimo DDS 400 mcg (formulated as the free base rather than the tartrate form). The biodegradable implant is delivered with a 25-gauge needle and dissolves more quickly, improving retinal exposure to the therapeutic agent. Patients are being treated every 3 months with Brimo DDS 400 mcg or sham, and the primary endpoint is at month 24.