Stargardt therapy receives orphan drug status

The FDA has granted orphan drug designation to Acucela’s drug candidate emixustat hydrochloride (emixustat) for the treatment of Stargardt disease.

The company is aiming to launch a proof-of-concept trial in 2018.

“We are very pleased to receive FDA’s orphan drug designation for emixustat to treat Stargardt disease,” said Dr. Ryo Kubota, MD, PhD, a chairman, president and CEO of Acucela. “We are actively advancing the development of emixustat to address this unmet medical need.”

The most common form of the disease is caused by a genetic mutation of the ABCA4 gene leading to the accumulation a toxic vitamin A byproduct called A2E in the retina, resulting in the gradual deterioration of photoreceptors and vision.

Emixustat is a non-retinoid small molecule inhibitor of retinal pigment epithelium protein 65 RPE65 that has been shown in preclinical research to stop the accumulation of A2E and preserve the integrity of the retina.

Earlier this year, results from a phase 2b/3 trial on emixustat for treatment of geographic atrophy secondary to AMD failed to meet its primary endpoint of reduced lesion growth rate compared to placebo. There was also no significant difference in change of BCVA from baseline to month 24 between the 2 groups.