PARIS, France — October 7, 2026
PulseSight Therapeutics SAS presented new early clinical data from its PST-611 Phase 1 trial in patients with advanced dry age-related macular degeneration (AMD), also known as geographic atrophy (GA), during an oral presentation at the 26th EURETINA Congress in Vienna. The presentation provided additional findings from the company’s first-in-human clinical study evaluating the safety, tolerability and early clinical activity of a single administration of PST-611. PulseSight said the new analysis showed positive early efficacy signals in five of six treated patients, adding to previously reported Phase 1 findings that demonstrated a favorable safety and tolerability profile at both evaluated dose levels. The company is developing PST-611 as a non-viral vectorized gene therapy designed to address underlying biological mechanisms involved in GA, a progressive retinal disease associated with loss of retinal pigment epithelium (RPE) and photoreceptors. The EURETINA presentation provides an important clinical update as PulseSight prepares to advance PST-611 into its next-stage clinical development program.
PST-611 Shows Early Structural Biomarker Signals
PulseSight conducted a quantitative post hoc analysis of optical coherence tomography (OCT) biomarkers following spontaneous reports from participants of perceived vision improvement and clinical observations suggesting a potential slowing of GA lesion growth. Using the RetinAI Discovery platform and artificial intelligence models, the company evaluated structural changes in four biomarkers associated with retinal cell loss before and after PST-611 administration. Across the full study population, PulseSight reported a consistent reduction in the mean growth rates of the evaluated biomarkers during the four months following treatment compared with the pre-treatment period, with reductions ranging from 35% to 52%. The company specifically reported a 40% reduction in the mean RPE depletion growth rate over the four-month post-treatment period. Additional findings included reductions in the growth rate of ellipsoid zone (EZ) depletion and EZ thickness loss, which were reported at 35% and 52%, respectively. PulseSight said these structural findings provide early signals that PST-611 may help preserve retinal structures involved in vision, although the company emphasized that the analysis was conducted post hoc in a small Phase 1 study.
PST-611 Targets Iron Homeostasis in Geographic Atrophy
PST-611 is a first-in-class gene therapy candidate designed to encode transferrin, a protein involved in regulating iron homeostasis. PulseSight is developing the therapy based on the rationale that dysregulated iron levels and transferrin oversaturation contribute to biological mechanisms associated with dry AMD and geographic atrophy. By enabling transferrin expression, PST-611 is designed to intervene in an upstream mechanism of GA pathogenesis and potentially influence multiple downstream processes involved in disease progression. The Phase 1 CT1 study enrolled six patients with advanced dry AMD/GA across two successive dose-escalation cohorts, with participants receiving a single administration followed by four months of follow-up. Earlier findings from the study established the primary and secondary objectives related to safety and tolerability, while the newly presented OCT analysis provides the first additional clinical evidence supporting potential biological activity. PulseSight said the results support further investigation of its non-viral ocular gene therapy platform and its approach to targeting retinal disease biology.
Advertisement
PulseSight Prepares Phase 2a PST-611 Trial
The new Phase 1 findings provide the clinical foundation for PulseSight’s planned Phase 2a study, PST-611-CT2a. The next-stage trial is designed to evaluate the safety and efficacy of PST-611 in up to 24 patients, with participants expected to receive up to three administrations over a 12-month period. PulseSight plans to evaluate whether the structural biomarker findings observed in the Phase 1 study can be reproduced in a larger patient population and over a longer treatment period. The company expects the Phase 2a program to provide additional information on the durability and clinical relevance of PST-611’s potential effects. The development strategy is particularly relevant in geographic atrophy, where significant unmet medical needs remain and treatment options are limited in several regions. With the Phase 1 study demonstrating favorable safety findings and early structural efficacy signals, PulseSight is advancing PST-611 toward Phase 2a development as it evaluates a potential new gene therapy approach for dry AMD and geographic atrophy.
Source::PulseSight Therapeutics, press release
