Sep 3, 2026

2026 Research Round-Up: Advances in Inherited Retinal Disease

Inherited retinal disease (IRD) research continues to move forward on many fronts. This year, one important trend we’re seeing is how many potential treatments are advancing into later stages of clinical testing. At the same time, researchers are finding new ways to tackle some of the biggest challenges in IRD research.

Here are some of the developments that have caught our attention over the past year.

More treatments are getting closer to the finish line

Developing a new treatment is a long process, and most experimental therapies that show promise in the laboratory never reach clinical trials. But several potential IRD treatments have now progressed into “pivotal” trials, the large, usually Phase 2 or Phase 3 studies generally needed before a treatment can be considered for approval.

One of the most advanced is tinlarebant, a once-daily oral treatment being developed for Stargardt disease caused by mutations in the ABCA4 gene. In 2025, we shared results from the Phase 3 DRAGON trial, where tinlarebant slowed the growth of areas of retinal damage by approximately 36 per cent compared with placebo. Earlier this month the U.S. Food and Drug Administration (FDA) agreed to review the drug, with a decision expected in 2027. If approved, tinlarebant could become the first approved treatment for Stargardt disease. Another oral treatment, Alkeus’ gildeuretinol (ALK-001), has also entered a pivotal Phase 3 trial. Gildeuretinol is designed to reduce the formation of toxic vitamin A byproducts that contribute to retinal damage in Stargardt disease.

There has also been progress for OCU400, an experimental gene therapy for retinitis pigmentosa (RP). Unlike traditional gene replacement therapies that target one particular mutated gene, OCU400 delivers a gene called NR2E3 that helps regulate multiple processes important to retinal health. This “modifier gene” approach could potentially benefit people with RP caused by different mutations. Enrollment in the Phase 3 liMeliGhT trial is now complete, with results expected in early 2027.

Another gene therapy, ATSN-201 is moving into pivotal testing for X-linked retinoschisis (XLRS). Early testing showed encouraging changes in retinal structure and measures of visual function, and a good safety profile, leading Atsena Therapeutics to launch the Phase 3 LIGHTHOUSE trial. The first participant has now been treated in with results expected in 2028.

Of course, these milestones don’t guarantee that a treatment will ultimately be approved. But collectively, they show a growing number of treatments for IRDs are reaching the stages of development where researchers can get much more definitive answers about whether they are safe and effective.

Finding new ways around old barriers

The treatment pipeline for Stargardt disease stands out this year not only because of the progress of tinlarebant, but because of the number of different treatment approaches that are entering clinical trials.

The majority of cases of Stargardt disease are caused by mutations in the ABCA4 gene. One of the challenges with developing a traditional gene replacement therapy is that ABCA4 is very large and cannot fit inside delivery vehicles like adeno-associated virus (AAV) vectors, commonly used for other retinal gene therapies like Luxturna.

Researchers are now testing different ways around this problem.

VeonGen’s VG801 uses two AAV vectors to deliver different portions of the ABCA4 gene, which are then reassembled inside retinal cells. Preliminary results from an ongoing Phase 1/2 trial have shown improvements in some measures of visual function, with no serious treatment-related safety events.

SpliceBio’s SB-007 uses another dual-vector strategy, combined with protein-splicing technology, to reconstruct full-length ABCA4 inside retinal cells. A Phase 1/2 ASTRA trial has now progressed into a dose-expansion stage that will compare different doses of SB-007 with an untreated control group.

More approaches are coming behind them. Atsena’s ATSN-401, another dual-vector gene therapy for Stargardt disease, is undergoing pre-clinical studies needed before human testing can begin. OCU410ST, meanwhile, avoids replacing ABCA4 altogether. Like OCU400, it is a modifier gene therapy designed to influence biological pathways involved in retinal health and is being evaluated in a Phase 2/3 trial.

The diversity of this pipeline is important and should increase the chance of identifying successful treatments. Instead of relying on a single solution, researchers are testing multiple ways to try and treat the same disease.

Other IRDs are also seeing new treatment programs. A Phase 1/2 trial, sponsored by Opus Genetics, has begun testing OPGx-MERTK for RP caused by mutations in MERTK, while preclinical studies are studying potential treatments for RP caused by mutations in LRAT and PRPF3.

While researchers develop treatments for known IRD genes, new discoveries are also helping identify previously unknown genetic causes of disease. A large international study published in Nature Genetics identified variants in several small nuclear RNA genes as a cause of nonsyndromic RP. Unlike most known IRD genes, these genes do not make proteins. Instead, they produce small RNA molecules involved in processing genetic information.

Researchers estimate that variants in these genes could explain approximately 1.4 per cent of previously undiagnosed RP cases, potentially providing answers for some people whose previous genetic testing has not identified the cause of their disease.

Even these early-stage programs represent an important expansion of the diagnosis and treatment pipeline.

Moving beyond one gene, one treatment

More than 300 genes have been linked to IRDs. This genetic diversity creates a major challenge: a treatment designed for one gene may only be relevant to a relatively small number of people.

That is why another important area of research focuses on gene-agnostic treatments ― therapies that could potentially work across multiple genetic forms of a disease.

One example is Sparing Vision’s SPVN06, a gene therapy designed to help protect cone photoreceptors from degeneration. Instead of correcting the mutation that originally caused RP, it aims to support the survival of the remaining photoreceptors. All participants have been treated in the Phase 1/2 PRODYGY trial, which includes people with RP caused by several different genes with initial results expected in 2027.

A very different approach is NPI-001, an oral drug being developed by Nacuity Pharmaceuticals for RP associated with Usher syndrome. The treatment is designed to reduce oxidative stress, a type of cellular damage thought to contribute to photoreceptor loss. In a Phase 1/2 trial, researchers reported that participants receiving NPI-001 had more than a 50 per cent reduction in photoreceptor loss over two years compared with participants receiving placebo. A Phase 3 trial is now planned to further test whether the treatment can slow retinal degeneration.

Researchers are also beginning to ask an even harder question: can vision be restored after photoreceptors have already been lost?

This August, the first participant was treated in a Phase 1/2a clinical trial of Sumitomo Pharma America’s DSP-3077, an experimental cell therapy for RP. Researchers start with human cells that have been reprogrammed into a stem-cell-like state and use them to grow retinal tissue containing photoreceptor precursor cells. A sheet of these cells is then surgically implanted beneath the retina.

Unlike treatments designed to protect photoreceptors that are still alive, the long-term goal is to replace some of the retinal cells already lost to disease. This is very early clinical research — the initial trial is primarily designed to evaluate safety — but it represents an important step for regenerative approaches to IRD.

Together, these strategies could potentially broaden who benefits from future treatments, including people whose particular disease-causing gene does not yet have a targeted therapy and, eventually, people with more advanced retinal degeneration.