A rare win in Stargardt research breathes fire into a field long stuck in slow motion.
In a field where progress often feels glacial, Belite Bio (California, USA) has delivered a rare headline: positive topline results from its global Phase III DRAGON trial evaluating tinlarebant in adolescents with Stargardt disease type 1 (STGD1). This is the first STGD1 Phase III trial to successfully meet its primary endpoint.
Tinlarebant, an oral therapy, slowed retinal lesion growth by 36% compared to placebo based on autofluorescence imaging. With no approved treatment currently available for STGD1, the findings position Tinlarebant as a potential first-in-class therapy. Belite Bio plans to submit a New Drug Application to the U.S. Food and Drug Administration (FDA) in the first half of 2026.
“The final results from the DRAGON trial mark a historic breakthrough in Stargardt disease, paving the way for the first potential treatment for this devastating condition and bringing new hope to patients and families who have long faced a disease once considered untreatable,” said Belite Bio Chairman and CEO Dr. Tom Lin in a news release.
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“Not only was tinlarebant shown to be efficacious in slowing retinal degeneration, but this is also the first time that an oral treatment was able to demonstrate a clinically meaningful outcome in retinal degenerative disease,” he added. “With this data, we are advancing our regulatory interactions globally and moving closer to delivering the first approved treatment for people living with Stargardt disease.”
Study overview
The DRAGON trial enrolled 104 adolescents aged 12 to 20 with confirmed STGD1 and at least one ABCA4 mutation. Participants had a baseline best corrected visual acuity (BCVA) of 20/200 or better and a lesion size of up to three disc areas (7.62 mm²). The study was randomized 2:1 (tinlarebant to placebo), double-masked, placebo-controlled and conducted over a 24-month treatment period.
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Efficacy highlights
Tinlarebant achieved the primary endpoint, demonstrating a statistically significant 36% reduction in the rate of lesion growth measured as definitely decreased autofluorescence (DDAF). The pre-specified analysis yielded a p-value of 0.0033, and a post analysis using an autoregressive covariance matrix showed similar consistency with a p-value of <0.0001.
Comparable results were observed in the fellow eye, with a 33.6% reduction in lesion growth (p = 0.041).
“The significant lesion growth reduction observed in the DRAGON study, along with the favorable safety profile, provide important validation of our therapeutic approach and the mechanism of tinlarebant,” said Dr. Nathan Mata, chief scientific officer at Belite Bio. “These results underscore the team’s commitment to addressing the unmet need in Stargardt disease and the potential to meaningfully improve the quality of life for those affected.”
The treatment also met its key secondary endpoint by slowing the progression of decreased autofluorescence (DAF), which includes both DDAF and questionably decreased autofluorescence (QDAF), again in both eyes. Visual acuity remained relatively stable across treatment and placebo groups throughout the 24-month study, consistent with expected natural history in this age range.
Safety of the treatment
Tinlarebant was generally well tolerated. The most common treatment-related effects were xanthopsia and delayed dark adaptation, both consistent with the therapy’s mechanism. Most cases were mild and resolved during treatment.
Four participants discontinued due to drug-related effects, and there were no discontinuations related to non-ocular adverse events.
Pharmacodynamic data showed an average reduction of approximately 80% in serum retinol binding protein 4 (RPB4) during treatment, with levels returning to about 84% of baseline after cessation.
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Looking ahead
As Belite Bio moves forward with regulatory submissions, tinlarebant now stands as a leading candidate to fill a long-standing therapeutic gap in inherited retinal disease. Further updates will clarify its regulatory trajectory, but the Phase III DRAGON results set a new benchmark—and just maybe, the field is finally getting its dragon-slaying moment.
Editor’s Note: This content is intended exclusively for healthcare professionals. It is not intended for the general public. Products or therapies discussed may not be registered or approved in all jurisdictions, including Singapore.