Belite Bio Reports Positive Results from Phase 2 Study of Tinlarebant in Childhood-onset Stargardt Disease
November 6, 2023
Rare Daily Staff
Belite Bio repoted positive final data from a 24-month, phase 2 study of Tinlarebant in adolescent Stargardt disease at the American Association of Ophthalmology (AAO) Annual Meeting.
“Tinlarebant’s final phase 2 results represent a significant milestone for Belite Bio and provide additional foundational support for the work being conducted across our trials,” said Tom Lin, chairman and CEO of Belite Bio. “The final phase 2 data continue to demonstrate Tinlarebant’s safety profile and show a sustained lower DDAF lesion growth compared to ProgStar participants over the two-year treatment period. We hope to see similar data in the ongoing phase 3 DRAGON study, further supporting Tinlarebant as a promising oral treatment for STGD1 patients.”
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.
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 geographic atrophy, 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 United States, and Orphan Drug Designation in the United States and Europe for the treatment of STGD1.
A total of 12 adolescent STGD1 subjects aged 12-18 years completed 24 months of treatment in the Phase 2 study of Tinlarebant. Tinlarebant was safe and well-tolerated with no withdrawals due to adverse events. Retinal imaging showed that 5 of 12 subjects remained free of atrophic retinal lesions (referred to as definitely decreased autofluorescence or DDAF) after 24 months of Tinlarebant treatment.
A comparison of the 24-month DDAF lesion growth between Tinlarebant-treated subjects and ProgStar participants possessing similar baseline characteristics (aged ≤18 years) showed a sustained lower DDAF lesion growth in Tinlarebant-treated subjects over the 24-month treatment period.
Visual acuity was stabilized in majority of subjects during the study with a mean loss of five letters following 24 months of treatment (a loss of <10 letters is not considered clinically significant).
John Grigg, the study’s principal investigator and head specialty of ophthalmology at the University of Sydney and consultant ophthalmologist at the Sydney Children’s Hospitals Network at Westmead and Sydney Eye Hospital, presented the final study data. “We are very encouraged by the promising 24-month treatment final results from this phase 2 study,” he said. “The natural progression of childhood-onset STGD1 is characterized by a rapid visual decline and fast disease progression leading to permanent visual loss at a very young age.”
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