In January 2017, Acucela had received orphan drug designation from the US Food and Drug Administration (FDA) for emixustat to treat Stargardt disease.
Stargardt disease is a rare and genetically inherited disease, which directly affects the retina of the eye and may result in the slow progression of vision loss in children.
According to the company, Stargardt disease may also be referred to as Stargardt macular dystrophy or juvenile macular degeneration that affects around one in 8,000 to 10,000 individuals across the world.
A genetic mutation of the ABCA4 gene will result in the disease. It leads to the accumulation of toxic vitamin A byproducts in the retina that will result in the gradual deterioration of photoreceptors and vision.
Emixustat is said to modulate the visual cycle by inhibiting a critical enzyme of this pathway, retinal pigment epithelium protein 65 (RPE65).
The visual cycle is the process through which vitamin A is recycled in the eye. The vitamin A is important to the visual process.
Slowing the visual cycle will decrease the availability of vitamin A derivatives (11-cis- and all-trans-retinal) to form precursors of A2E and related compounds.
Emixustat was showed to stop and reverse the accumulation of A2E, as well as preserve the integrity of the retina in animal models of Stargardt disease.
When delivered orally, emixustat was demonstrated to be generally well tolerated in human clinical studies with delayed dark adaptation.
The company intends to explore the potential of emixustat to block or slow the progression of vision loss in patients diagnosed with Stargardt disease in ongoing and future clinical studies.
Acucela is a wholly-owned subsidiary of Kubota Pharmaceutical Holdings, which has diverse portfolio of drugs and devices for the restoration of vision.
The development pipeline of Acucela is comprised of drug candidates to treat diabetic retinopathy, diabetic macular edema, Stargardt disease, age-related macular degeneration, cataracts and presbyopia, and, optogenetics-based gene therapy for the treatment of retinitis pigmentosa.