Promising results from a phase 2 study indicate that Apellis Pharmaceuticals’ conjugated peptide candidate (APL-2) is effective at slowing progression of geographic atrophy (GA) associated with AMD.

The novel drug is a derivative of compstatin, a small peptide that inhibits complement component 3 (C3). Activation of C3 is essential for all 3 pathways of the complement cascade, which plays a key role in a wide range of autoimmune and inflammatory diseases. Previous research has implicated that dysregulation in the complement system plays a role in AMD pathogenesis.

Apellis’ multicenter, single-masked study randomized 246 patients to receive intravitreal APL-2 or sham injections either monthly or every-other-month for 1 year, followed by 6 months of post-treatment monitoring.

According to the press release, patients who received monthly APL-2 showed 29% reductions in the rate of GA lesion growth compared with sham eyes at month 12. The bimonthly APL-2 arm also showed delayed lesion growth compared with sham (20%), but this difference did not reach statistical significance.

Additionally, a post hoc analysis suggests that the treatment effect may increase over time, as the growth rate reduction during the second 6 months of the study was higher: 47% for the monthly group and 33% for bimonthly. The press release did not, however, detail if the C3 inhibitor provided any visual benefits.

The most commonly reported adverse events were associated with the injection procedure. A higher incidence of exudative AMD was observed in the APL-2 arms, which was successfully managed with standard therapies.

“We are very excited about the results of this study,” said Cedric Francois, MD, PhD, founder and CEO of Apellis. “In addition to demonstrating a statistically significant slowing of disease over 12 months, APL-2’s effect appears to increase in the second six months of the study, slowing down the rate of degeneration by almost half. We plan to move forward with Phase 3 studies as soon as possible.”