The US Food and Drug Administration has cleared the investigational new drug application for CTx001, an adeno-associated virus–based gene therapy developed by Complement Therapeutics for geographic atrophy (GA) secondary to age-related macular degeneration (AMD). The clearance allows initiation of the Opti-GAIN phase 1/2 trial, a first-in-human study evaluating safety, tolerability, and preliminary efficacy of the therapy.

CTx001 is designed to deliver a truncated version of complement receptor 1 (mini-CR1), intended to modulate both the classical and alternative complement pathways. The Opti-GAIN trial will enroll patients at multiple centers in the United States and United Kingdom, with first dosing expected in early 2026. Trial design has been informed by i-GAIN, a natural history study that included more than 230 participants and generated data on biomarkers and disease progression. RP