PulseSight Therapeutics Completes Phase I Dosing for Novel Gene Therapy PST-611 in Geographic Atrophy
Key Insights
PulseSight Therapeutics (search) has completed enrollment in its Phase I clinical trial of PST-611, a first-in-class gene therapy targeting dry age-related macular degeneration and geographic atrophy.
The trial treated six patients across two dose cohorts to assess safety and tolerability of the transferrin-expressing therapy delivered via electro-transfection technology.
PST-611 addresses iron homeostasis dysregulation in dry AMD by expressing transferrin protein, which has shown protective effects on retinal cells in animal models.
PulseSight Therapeutics (search) SAS has completed patient enrollment in its Phase I clinical trial of PST-611, a novel gene therapy for dry age-related macular degeneration (AMD) and geographic atrophy (GA). The Paris-based ophthalmology biotech company announced that six patients have been treated across two successive cohorts at different dose levels, with trial data scheduled for presentation at the 2026 ARVO Annual Meeting from May 3-7.
Addressing Critical Unmet Medical Need
AMD represents the leading cause of central vision loss in the elderly, affecting 200 million people worldwide. Geographic atrophy, the advanced form of dry AMD, remains an area of high unmet medical need, lacking efficient and well-tolerated treatments that can prevent disease progression.
"Late-stage dry AMD/GA is a progressing disease that leads to vision loss and for which we have no therapeutic options for our patients," said Professor Francine Behar-Cohen, MD, PhD, at the Department of Ophthalmology, Cochin – Assistance Publique-Hôpitaux de Paris (AP-HP), who is conducting the study alongside Professor Christophe Chiquet, MD, PhD, at CHU Grenoble Alpes.
Novel Mechanism Targeting Iron Homeostasis
PST-611 represents a first-in-class therapeutic candidate that expresses transferrin, a natural iron transporter crucial for controlling normal iron homeostasis. The therapy addresses a key pathological mechanism in dry AMD, where dysregulation of iron homeostasis leads to excess free iron causing inflammation, oxidative stress, and ultimately retinal cell death through ferroptosis.
In preclinical studies, PST-611 demonstrated protective effects on photoreceptors and retinal pigment epithelium (RPE) cells, preserving visual function in animal models. The therapy is designed to require re-treatment only every four to six months.
Innovative Delivery Technology
The treatment utilizes PulseSight's proprietary electro-transfection technology, which delivers DNA plasmids encoding therapeutic proteins directly into the ciliary muscle of the eye. Professor Behar-Cohen, who pioneered this delivery approach, noted her enthusiasm for the technology's potential.
"Having pioneered the development of the electro-transfection technology that delivers DNA plasmids encoding therapeutic proteins into the ciliary muscle of the eye, I am very enthusiastic about PST-611," she said. "Based on its mechanism of action and thanks to the innovative delivery technology, PST-611 has potential to become a major treatment option for these patients."
Clinical Development Progress
The Phase I study assessed PST-611's safety and tolerability in dry AMD/GA patients, treating participants in Paris and Grenoble. George Weissgerber, MD, PulseSight's Chief Medical Officer, expressed satisfaction with the trial completion and gratitude to the investigating teams.
"We are very pleased to have completed the enrolment of the patients in the phase I trial and thankful to our investigators and their team for their involvement and support," Weissgerber said. "This trial marks the first step of PST-611 clinical development and provides the foundation to build upon for the phase IIa trial we are already preparing to further demonstrate PST-611's potential."
The company's technology platform enables ciliary muscle cells to function as biofactories, expressing therapeutic proteins that reach the retina with high distribution, providing what the company describes as safe and long-lasting treatment for major eye diseases. PulseSight's investors include Pureos Bioventures, ND Capital, and Korea Investment Partners (KIP).