Hope for Dry AMD: Novel Gene Therapy Completes First Human Safety Trial

PARIS, FRANCE – April 23, 2026 – In a significant development for the millions suffering from a leading cause of age-related blindness, PulseSight Therapeutics announced today the completion of its Phase I clinical trial for PST-611, a novel gene therapy for the dry form of Age-related Macular Degeneration (AMD) and its advanced stage, Geographic Atrophy (GA). The Paris-based biotech company confirmed that the last patient has finished their final follow-up visit, clearing the way for the first public presentation of the trial’s safety and tolerability results.

The highly anticipated data will be unveiled at the upcoming Association for Research in Vision and Ophthalmology (ARVO) 2026 Annual Meeting in Denver, Colorado. Professor Francine Behar-Cohen, the trial's lead investigator and a pioneer of the underlying technology, is scheduled to present the findings on May 7.

The announcement marks a critical milestone for a first-in-class therapy that diverges from current treatment paradigms. By using a non-viral delivery system to address iron-induced cell death in the retina, PST-611 represents a potential new front in the fight against a disease that has long frustrated patients and clinicians alike.

A Disease in Search of a Breakthrough

Age-related Macular Degeneration is the primary cause of irreversible central vision loss in the elderly, affecting an estimated 200 million people globally. The vast majority of cases are the 'dry' form, which progresses slowly, robbing individuals of the sharp, straight-ahead vision necessary for reading, driving, and recognizing faces. In its advanced stage, known as Geographic Atrophy, patches of retinal cells die off, creating permanent blind spots.

Until recently, patients with GA had no approved treatment options. The landscape shifted with the 2023 approvals of Syfovre® and Izervay™, two therapies that target the complement system, a part of the body's immune response implicated in the disease. While these drugs represent a major scientific advance by slowing the growth of GA lesions, their limitations highlight the vast unmet need that remains.

Current treatments do not halt or reverse vision loss; they merely slow the decline. Furthermore, they impose a significant treatment burden, requiring injections directly into the eye every one to two months. This frequent, invasive procedure carries its own risks and is a major drawback for an elderly patient population. The modest functional benefits have even led some European regulatory bodies to question their overall value, leaving a clear opening for therapies that can offer a more durable effect with a better safety and delivery profile.

Targeting Iron: A Novel Mechanism of Action

PST-611 sidesteps the complement pathway entirely, instead targeting a different biological process increasingly understood to be a key driver of retinal cell death in dry AMD: iron overload. Research has shown that in the aging eye, the delicate system that manages iron can break down. This leads to an excess of free iron, which is highly toxic to retinal cells. The resulting oxidative stress and inflammation can trigger a form of programmed cell death called ferroptosis, contributing directly to the atrophy seen in GA.

PulseSight’s therapy is designed to restore this balance. PST-611 is a vectorized gene therapy that delivers a DNA plasmid encoding for transferrin, a naturally occurring protein that acts as the body’s primary iron transporter. The goal is to increase the local concentration of transferrin in the eye, enabling it to bind to the excess free iron and neutralize its toxic effects. By doing so, the therapy aims to protect the vital photoreceptor and retinal pigment epithelium (RPE) cells from ferroptosis, thereby preserving retinal structure and visual function.

This approach is supported by promising preclinical data from animal models, where PST-611 demonstrated the ability to shield retinal cells from death and maintain vision. The now-completed Phase I trial, which enrolled six patients across two dose levels in Paris and Grenoble, was designed as the first crucial test of whether this mechanism is safe and tolerable in humans.

The Promise of Non-Viral Gene Therapy

Beyond its unique biological target, what sets PST-611 apart is its delivery technology. Most ocular gene therapies in development rely on viral vectors, typically adeno-associated viruses (AAV), to shuttle genetic material into cells. While effective, viral vectors have limitations, including a restricted payload capacity for genetic code and the potential to trigger an immune response that could compromise safety and efficacy.

PulseSight employs a non-viral approach. The therapy uses a minimally-invasive procedure involving electro-transfection to deliver the transferrin-encoding DNA plasmid into the ciliary muscle, a ring of tissue near the front of the eye. This turns the muscle cells into tiny, localized “biofactories” that continuously produce and secrete the therapeutic transferrin protein into the eye, allowing it to reach the affected tissues at the back of the retina.

This platform offers several potential advantages. Non-viral vectors are generally considered to have a better safety profile, with lower immunogenicity. They can also carry larger genetic payloads than many viral vectors, opening the door for more complex future therapies. Most importantly for patients, this method holds the promise of a long-lasting therapeutic effect from a single administration, potentially reducing the need for frequent injections to just a few times per year, or even less. The success of this platform could represent a paradigm shift in how chronic ocular diseases are managed.

A Milestone on a Long Road

The completion of the Phase I trial is a pivotal moment for the French biotech company. “Presentation of the results of our first in human clinical trial of PST-611 at a major ophthalmology conference is a significant milestone for the company,” said George Weissgerber, MD, PulseSight's Chief Medical Officer, in a statement. “The progress made over the past year is very encouraging for the project and for patients.”

With a global GA market projected to reach nearly $4 billion by the early 2030s, the commercial opportunity for a differentiated, effective, and less burdensome therapy is immense. PulseSight is already looking ahead, with Weissgerber confirming that the company will be “building upon this trial in the planned phase IIa study to further demonstrate PST-611’s potential.”

The initial human data from the six-patient study will provide the first clues as to whether the therapy’s strong preclinical performance and innovative design can translate into a safe and viable treatment for humans. All eyes in the ophthalmology world will now be on Denver, where the first human data will reveal if this innovative approach holds the key to preserving sight for millions.