Beacon's Gene Therapy Laru-zova Restores Dim-Light Vision in Pivotal Trial for Rare Blinding Disease

The US Food and Drug Administration will soon decide whether to approve the first gene therapy for a rare, progressive blinding disease, following a pivotal clinical trial that successfully restored patients' ability to see in dim light. Beacon Therapeutics announced Monday that it plans to initiate a rolling Biologics License Application before the end of 2026 for laru-zova, a one-time treatment for X-linked retinitis pigmentosa.[1][3]

The decision hinges on new data from the Phase 2/3 VISTA trial, which tested the therapy in 85 male patients aged 12 to 48. X-linked retinitis pigmentosa, caused by mutations in the RPGR gene, typically begins with night blindness in childhood and progressively narrows peripheral vision until it causes legal blindness. Currently, no approved treatments exist to slow or reverse the condition.[1][4]

Laru-zova works by delivering a functional copy of the RPGR gene directly to the retina using an adeno-associated virus vector. The goal is to restore the natural function of both rod and cone photoreceptors. In the VISTA trial, patients were randomized to receive either a high dose of 6.8 trillion vector genomes per eye, a low dose of 3.7 trillion vector genomes, or to remain in an untreated control group.[1][6]

The trial's primary endpoint measured low-luminance visual acuity—a critical metric for this patient population, as difficulty seeing in dim light is often the first and most debilitating symptom. After 12 months, 31.0% of patients in the high-dose group and 24.1% in the low-dose group achieved an improvement of at least 15 letters on a standard eye chart under low-light conditions.[1][2]

By contrast, none of the patients in the untreated control group achieved a 15-letter improvement. The therapy also showed broader efficacy trends: 48.3% of the high-dose group and 58.6% of the low-dose group gained at least 10 letters of low-luminance vision, compared to just 3.7% of the untreated cohort.[2][7]

For patients and their families, these numbers translate to tangible differences in daily navigation and independence. A 15-letter gain is equivalent to reading three additional lines on an eye chart, a threshold widely recognized by regulators as clinically meaningful. "Beacon selected endpoints that would best capture improvements that matter to patients, particularly their ability to see in low-light conditions, which is one of the most challenging aspects of living with XLRP," said Dr. Robert Sisk, a trial investigator and professor of ophthalmology at the University of Cincinnati.[6]

Safety data from the trial aligned with previous early-stage studies. Beacon reported that treatment-emergent adverse events were predominantly mild to moderate and localized to the eye, occurring in 25% of the high-dose group and 38% of the low-dose group. Two serious ocular adverse events were recorded in the low-dose cohort, both of which investigators attributed to the surgical procedure required to administer the subretinal injection rather than the gene therapy itself.[1][6]

The VISTA results distinguish Beacon's program in a challenging developmental landscape. Earlier in 2026, a competing RPGR-directed gene therapy from MeiraGTx failed to meet its primary endpoint in a Phase 3 trial, which had relied on a navigation-based functional vision test rather than the FDA-endorsed low-luminance visual acuity metric used by Beacon.[3][7]

While the topline data are definitive enough to support regulatory filings, full trial results are scheduled for a late-breaking presentation at the American Academy of Ophthalmology annual meeting on October 10, 2026. If the FDA accepts the forthcoming application, laru-zova could reach clinics by late 2027. In the meantime, patients with X-linked retinitis pigmentosa should consult their retinal specialists about genetic testing to confirm their RPGR mutation status, as this will be required for eligibility if the therapy is approved. Long-term monitoring will also be necessary to determine how many years the vision restoration lasts after the single injection.[1][4]