Acucela Inc, a clinical-stage ophthalmology company that specializes in identifying and developing novel therapeutics to treat and slow the progression of sight-threatening ophthalmic diseases, announced that the company initiated a phase 2 clinical trial with the successful enrollment of the first patient, to assess the benefits of emixustat hydrochloride (emixustat) for the treatment of proliferative diabetic retinopathy (PDR).

Acucela has submitted a clinical study protocol to the US Food and Drug Administration (FDA) and has received Institutional Review Board approval to initiate a randomized, placebo-controlled, phase 2 clinical trial evaluating emixustat in patients with PDR. In this three-month study, 20 patients will be dosed once daily with oral emixustat. Pre-specified study endpoints include changes in cytokine expression levels associated with PDR severity and changes in ocular neovascularization. With the enrollment of the first patient, the phase 2 clinical trial is under way.

Diabetic retinopathy is a progressive condition in which damage to the retinal microvasculature occurs as a result of chronic hyperglycemia. These vascular changes eventually lead to a chronic decrease in oxygen supply (hypoxia) to the retina. PDR occurs when chronic retinal hypoxia causes proliferation of new, fragile vessels that tend to leak fluid and blood.  This is the most advanced stage of diabetic eye disease and can result in permanent vision loss. PDR affects over 19 million people worldwide today, and this number is expected to grow to almost 22 million by 20201.

“I am excited to explore the potential benefit of emixustat in this serious sight threatening retinal disease affecting millions throughout the world,” stated Ryo Kubota, MD, PhD, and chairman, president and CEO of Acucela.

Emixustat hydrochloride (emixustat) is a once-daily, orally administered small molecule that inhibits RPE65, an enzyme crucial to the visual cycle, the chemical pathway in the retina central to the initiation of visual perception. Emixustat has been shown to play a critical role in slowing the progression of multiple retinal degenerative diseases in animal models, including geographic atrophy (GA) secondary to age related macular degeneration (AMD). Emixustat is being developed by Acucela in collaboration with Otsuka Pharmaceutical Co., Ltd. (Otsuka). Acucela and Otsuka share commercial rights for emixustat in the USA. Otsuka has exclusive rights in Japan and Asia, while Acucela has exclusive rights in Europe and other countries. Acucela has received fast-track designation for emixustat for the treatment of GA secondary to dry AMD by the US Food and Drug Administration (FDA).