Belite Bio Inc. announced its submission to the Pharmaceuticals and Medical Devices Agency (PMDA) to initiate a clinical trial of Tinlarebant in adolescent STGD1 in Japan (?DRAGON II?). The DRAGON II trial is a combination of Phase 1b open-label study to evaluate the pharmacokinetics and pharmacodynamics of Tinlarebant in Japanese adolescent STGD1 subjects and a Phase 2/3, global, multicenter, double-masked, placebo-controlled, randomized study designed to evaluate the efficacy, safety and tolerability of Tinlarebant in adolescent STGD1 subjects. Approximately 60 subjects, aged 12 to 20 years old, including approximately 10 Japanese subjects, are targeted for enrollment in the Phase 2/3 portion of the trial with a 1:1 randomization (tinlarebant:placebo).

The data from Japanese subjects is intended to facilitate future NDA applications in Japan. Tinlarebant is a novel oral therapy that is intended to reduce the accumulation of vitamin A-based toxins (known as bisretinoids) that cause retinal disease in STGD1 and also contribute to disease progression in GA, or advanced Dry AMD. Bisretinoids are by-products of the visual cycle, which is dependent on the supply of vitamin A (retinol) to the eye.

Tinlarebant works by reducing and maintaining levels of serum retinol binding protein 4 (RBP4), the sole carrier protein for retinol transport from the liver to the eye. By modulating the amount of retinol entering the eye, Tinlarebant reduces the formation of bisretinoids. Tinlarebant has been granted Fast Track Designation and Rare Pediatric Disease designation in the U.S., and Orphan Drug Designation in the U.S., Europe, and Japan for the treatment of STGD1.

STGD1 is the most common inherited retinal dystrophy (causing blurring or loss of central vision) in both adults and children. The disease is caused by mutations in a retina-specific gene (ABCA4), which results in progressive accumulation of bisretinoids leading to retinal cell death and progressive loss of central vision. The fluorescent properties of bisretinoids and the development of retinal imaging systems have helped ophthalmologists identify and monitor disease progression.

Currently, there are no FDA approved treatments for STGD1. Importantly, STGD1 and GA, or advanced Dry AMD, share a similar pathophysiology, which is characterized by the excessive accumulation of bisretinoids, retinal cell death, and progressive loss of vision. Vision loss occurs slowly, despite peripheral expansion of ?dead retina,?

until the disease reaches the center of the eye (the macula). Therefore, Belite Bio is evaluating safety and efficacy of Tinlarebant in GA patients in a 2-year Phase 3 study (PHOENIX). Dry AMD is a leading cause of vision loss in older adults.

Geographic Atrophy, or GA, is the advanced stage of AMD. Currently, there are no FDA approved orally administered treatments for GA and no FDA approved therapies for the other stages of Dry AMD other than GA. There are an estimated 20 million AMD patients in the U.S. and over 196 million patients worldwide with an estimated global direct healthcare cost of USD 255 billion.