A one-time gene therapy for a rare inherited disease that blinds boys and young men has met the main goal of its largest trial, its maker Beacon Therapeutics says. After a year, about a quarter to a third of treated patients could read at least 15 more letters on an eye chart in dim light, while no untreated patients did1. Beacon announced the headline results on September 21 and presented more detail at the American Academy of Ophthalmology meeting in New Orleans on October 101. The data have not yet been published in a peer-reviewed journal.
What happened
The treatment, called laruparetigene zovaparvovec or laru-zova, is meant for X-linked retinitis pigmentosa, often shortened to XLRP. The disease usually begins with night blindness, moves on to loss of side vision and can end in blindness2. It mostly affects boys and young men because the faulty gene sits on the X chromosome2. One estimate puts the number of affected men and boys in the US at about 6,8002.
The trial, named VISTA, enrolled 85 males aged 12 to 48 whose disease is caused by changes in a gene called RPGR1. They were split by chance into three equal-sized groups: 29 got a higher dose, 29 got a lower dose and 27 got no treatment1. Each treated person received the gene therapy in one eye3. Everyone was followed for 12 months4.
Beacon says VISTA is the “first and only pivotal trial” in XLRP to reach its main goal5. A pivotal trial is the large study a company uses to ask regulators for approval.
The evidence so far
The main test was low-light reading vision: how many letters a person can read on a standard eye chart when the light is dimmed. The goal was the share of people who gained 15 letters or more, which is about three lines on the chart4.
- Higher dose: 31.0% gained 15 or more letters1.
- Lower dose: 24.1% gained 15 or more letters1.
- No treatment: nobody gained that much1.
Both dose results were statistically significant, meaning they were unlikely to be due to chance alone4. On a smaller gain of 10 letters or more, the numbers were 48.3% for the higher dose, 58.6% for the lower dose and 3.7% for untreated patients1. Beacon also reported that 13.8% of the higher-dose group and 6.9% of the lower-dose group gained 20 letters or more, a measure it says was not a defined goal of the trial1.
A second kind of test, called microperimetry, measures how well the central retina picks up faint spots of light. Treated eyes did better than untreated eyes on average, but the difference was statistically significant only for the lower dose4. BioPharma Dive noted that some of the secondary results were not statistically significant5.
On safety, Beacon says most eye side effects were mild to moderate, similar across groups and mostly tied to the surgery used to inject the treatment under the retina4. Side effects judged related to laru-zova itself were reported in 25% of the higher-dose group and 38% of the lower-dose group4. Two serious eye side effects occurred, both in the lower-dose group, and both were attributed to the surgery6.
What it does not show yet
The full results have so far come through company statements and a meeting talk, not a journal paper. Outside experts have not yet been able to check all the data.
The untreated group did not receive a fake procedure, so patients knew whether they had been treated7. The doses also did not line up neatly: the higher dose did better on the 15-letter test, while the lower dose did better on the 10-letter test, and the retina sensitivity results were similar between the two4. Hosts of the RetinUp retina podcast said the lack of a clear dose pattern “may raise FDA questions about dose selection,” though they added that gene therapies do not always behave in a straight line, and that manufacturing will also face scrutiny7.
The trial also says nothing yet about how long any gain lasts beyond one year, or about people with more advanced disease. The podcast hosts said enrollment required reading vision between 20/32 and no worse than 20/200, so patients may need to be found and genetically tested early7.
Who is behind it
Laru-zova was first developed by Applied Genetic Technologies Corp., which the healthcare investor Syncona took private in 2022 and folded into what became Beacon5. The treatment was then called AGTC-5012. Beacon launched in 2023 in the UK and also has a base in Cambridge, Massachusetts2.
Beacon ran and paid for the trial, and the main numbers come from its own announcements. The doctor who presented the data, Robert Sisk of the Cincinnati Eye Institute, spoke about the choice of the low-light test in a statement provided by Beacon5. The patient charity Foundation Fighting Blindness, whose chief executive Jason Menzo welcomed the results6, funded the early lab research behind the gene therapy8.
Beacon’s chief executive, Lance Baldo, described the results this way6:
Today’s data are both statistically significant and clinically meaningful, representing an important milestone for ocular gene therapy and demonstrating the potential for a one-time treatment to change the course of an inherited retinal disease.
How it fits the field
Laru-zova uses a harmless virus shell, known as AAV, to carry working copies of the RPGR gene into retinal cells8. Beacon says 70% to 90% of XLRP cases are caused by changes in that gene8.
Other gene therapies aimed at the same gene have struggled. A program Biogen bought failed in testing in 20215. In May 2025, Johnson & Johnson’s late-stage trial of another RPGR gene therapy missed its main goal, which measured how well patients could find their way around using their sight4. Ophthalmology Times noted that comparing trials has clear limits, but said the gap shows how much the choice of test has shaped this field4.
Laru-zova has been tested in earlier, smaller trials named HORIZON, SKYLINE and DAWN, and Beacon says 110 people have now been treated across its studies4. At the Retina Society meeting in September, Cleveland Clinic’s Aleksandra Rachitskaya reported that in DAWN, where patients’ second eyes were treated, the therapy was well tolerated and treated eyes gained more lines of low-light vision than untreated eyes9. For context, Biohack recently covered a different gene approach for retinitis pigmentosa that works regardless of which gene is broken.
What to watch next
Beacon says it plans to talk with regulators around the world and to begin a rolling application for US approval, which is sent in pieces, later in 20266. The treatment already has several faster-review designations, including Fast Track and RMAT from the FDA and PRIME from the European Medicines Agency4. Beacon plans to combine VISTA with its earlier studies to support filings in the US and Europe3.
A separate trial, LANDSCAPE, is testing the safety of treating both eyes within weeks of each other8. Key questions ahead are whether a peer-reviewed paper confirms the numbers, how regulators view the dose results, and whether the dim-light gains hold up over longer follow-up.
