Stealth BioTherapeutics announced top-line data from its Phase 2 ReCLAIM-2 trial evaluating elamipretide in patients with geographic atrophy (GA) secondary to dry age-related macular degeneration. Although the trial did not meet its primary endpoints assessing mean changes in LLVA and GA, a key secondary endpoint showed however that elamipretide categorically improved visual function for patients with GA. Additionally, elamipretide demonstrated proof of mechanism by reducing progressive ellipsoid zone loss, a key biomarker of retinal mitochondrial health which has been shown to be predictive of long-term GA growth and development.

Based on these data, the Company currently plans to progress development initiatives intended to better position this indication for potential partnering consistent with previous guidance. ReCLAIM-2 was a randomized, double-masked, parallel-group, placebo-controlled trial to evaluate the efficacy and safety of elamipretide over 48 weeks in 176 patients with GA. Elamipretide improved LLVA relative to placebo, although the mean change (primary endpoint) was not statistically significant.

Administration of elamipretide resulted in a 2 or more line gain in LLVA for greater than 15% of patients completing the 48-week trial (p=0.04). Although this improvement in visual function was not associated with reduced GA progression (primary endpoint), a significant reduction in ellipsoid zone loss (p=0.0034) was observed. Elamipretide was generally well tolerated in ReCLAIM-2. Injection site reactions were the most commonly observed adverse events and in some cases led to early termination.

The rate of new-onset exudations was 5% for patients treated with elamipretide versus 7% for patients treated with placebo.