Baseline OCT features may determine visual gain response to risuteganib in AMD
A phase 2 study found baseline OCT features, such as greater outer retinal volume or thickness, in patients with non-exudative age-related macular degeneration may affect visual gains when treated with risuteganib.
“It was a dramatic difference looking at the eyes who got risuteganib who did respond vs. those who didn’t respond in terms of these outer retinal parameters,” Justis P. Ehlers, MD, said in discussion of the study at the virtual American Society of Retina Specialists meeting.
Ehlers and colleagues conducted the double-masked, placebo-controlled clinical study and evaluated patients with non-exudative AMD who were randomly assigned to treatment with intravitreal 1 mg risuteganib or sham injection at baseline.
Researchers performed a post hoc analysis to determine the impact of baseline OCT features on response to risuteganib. The primary outcome of the study was percentage of subjects with a gain in best corrected visual acuity of eight letters or more from baseline to week 28 in the risuteganib group compared with baseline to week 12 in the sham group.
The study included 25 patients treated with risuteganib and 14 in the sham/crossover cohort. At week 16, patients in the risuteganib group received a second dose, and the sham group crossed over to receive 1 mg risuteganib. At 28 weeks, 48% of risuteganib patients gained eight or more letters compared with 7.1% of patients in the sham/crossover cohort, a statistically significant difference (P = .013).
Two independent reading centers evaluated “responders,” defined as patients treated with risuteganib in the study who gained eight or more letters, and confirmed outer retinal thickness was significantly higher in responders. Responders also displayed thicker photoreceptor layers when compared with non-responders. Additionally, the ellipsoid zone defect areas were significantly larger in non-responders compared with responders, Ehlers said.
“Many of these biomarkers may be looked at in other trials as well. Specifically, with the risuteganib studies, what we want to do is be sure we’re including those eyes that have the best chance to respond,” Ehlers said in discussion of the study.
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Ehlers JP, et al. Impact of baseline OCT characteristics on response to risuteganib for the treatment of intermediate age-related macular degeneration. Presented at: American Society of Retina Specialists annual meeting; July 24-26, 2020 (virtual meeting).