Complement Therapeutics has dosed the first patient in its phase 1/2 Opti-GAIN trial, marking the company’s first-in-human study of its gene therapy CTx001 for geographic atrophy (GA) secondary to age-related macular degeneration (AMD). The multicenter study is evaluating the safety, tolerability, and preliminary efficacy of a single subretinal injection of CTx001.

CTx001 is an adeno-associated virus–based gene therapy designed to deliver a truncated form of complement receptor 1, known as mini-CR1. The approach aims to provide sustained modulation of both the classical and alternative complement pathways, which are implicated in the pathophysiology of GA.

The trial’s open-label dose-escalation phase includes 3 dose cohorts, followed by a dose-expansion phase. Opti-GAIN is being conducted alongside Pre-GAIN, an ongoing natural history study in the United States and United Kingdom that aims to support endpoint development and patient selection. Novel structural and functional assessments, including ellipsoid zone measurements and focal OCT-based microperimetry, will be used to evaluate treatment effects.

Earlier this year, the US Food and Drug Administration (FDA) granted Fast Track status to CTx001. This designation is intended to facilitate the development and review of therapies for serious conditions with unmet medical needs and allows for more frequent interaction with the FDA. OM