Belite plans filing for oral Stargardt drug after phase 3 win

Belite Bio has said the results of the DRAGON trial of its oral therapy for sight-robbing disorder Stargardt disease type 1 (STGD1), tinlarebant, could support an FDA filing.

The San Diego biotech said that DRAGON is the first successful pivotal trial in patients with STGD1, an eye disease that leads to progressive vision loss, usually starting in childhood or young adulthood, and has no approved treatment worldwide. Around 50,000 people are living with Stargardt disease in the US.

Tinlarebant is designed to reduce the accumulation of vitamin A-based toxins or 'bisretinoids', which is a feature of the disease, by blocking a molecule that transports vitamin A (retinol) into the eye.

In the 104-patient, phase 3 trial, a daily oral dose of tinlarebant achieved the primary efficacy endpoint by demonstrating a 35.7% reduction in the growth rate of STGD1 lesions in the retina compared to placebo over 24 months, which was a highly statistically significant result.

Belite's chief executive and chairman, Dr Tom Lin, said the results "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."

He added: "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."

Belite is now planning to file for approval of tinlarebant in the US in the first half of 2026, and will also start talking to other regulatory authorities around the world about paths to market.

It's worth noting that the change to visual acuity was minimal among patients in both groups over the two years of follow-up, which the company said was "consistent with natural history data."

The lead DRAGON investigator in the UK, Prof Michel Michaelides of Moorfields Eye Hospital, said: "Given the strength and consistency of these findings, we believe an approved treatment option is on the horizon for people living with this devastating condition."

Efforts to develop therapies for Stargardt disease have proved fruitless so far, although candidates from Ocugen, Splice Bio, and VeonGen are among those also at the clinical testing stage.

Ocugen is running the phase 2/3 GARDian3 pivotal trial of its AAV-based gene therapy OCU410ST, which delivers the RORA gene, with results due next year. Meanwhile, SpliceBio's protein splicer SB007 and VeonGen's mRNA splicer VG801 are both in phase 1/2 for Stargardt patients carrying ABCA4 mutations.

Image by Monica Volpin from Pixabay