US-based Acucela has completed the treatment period in the current Phase llb/lll clinical trial of the investigational visual cycle modulator emixustat hydrochloride (emixustat).

Emixustat is a once-daily, orally administered small molecule that inhibits RPE65, which is an enzyme vital to the visual cycle, the chemical pathway in the retina central to the initiation of visual perception.

The molecule is being currently developed by Acucela in collaboration with Otsuka Pharmaceutical.

The safety and efficacy assessment treatment trials of emixustat hydrochloride (SEATTLE) study enrolled 508 patients with geographic atrophy (GA) secondary to dry age-related macular degeneration (AMD), an advanced form of age-related AMD, affecting more than nine million people worldwide.

"The trial’s main objective is to identify differences in lesion growth rate between treatment groups."

The last patient of the study has completed the treatment period of 24 months. The trial’s main objective is to identify differences in lesion growth rate between treatment groups.

The SEATTLE study compared the efficacy and safety of emixustat to placebo to treat GA secondary to dry AMD.

During the study, subjects were randomised to receive emixustat 2.5mg, 5mg, 10mg, or placebo, administered orally once-daily for up to 24 months.

Acucela intends to analyse and report top-line data from this clinical trial by June this year.

The study’s primary efficacy endpoint was the mean rate of change from baseline in the total area of the GA lesion(s) in the eye as imaged by fundus autofluorescence.

Secondary efficacy endpoints involved the mean change from baseline in normal luminance best-corrected visual acuity score and the proportion of subjects who developed choroidal neovascularization in their study eye.

Safety and tolerability were evaluated on the basis of ocular and non-ocular adverse events, serious adverse events, ophthalmic examination findings, vital signs, physical examination findings, electrocardiogram findings, and laboratory analyses.