Sylentis Announces Positive Phase 2a Results for Eye Drop siRNA Therapy SYL1801 in nAMD

Sylentis has released promising topline results from its phase 2a study evaluating SYL1801, an investigational siRNA eye drop therapy, for the treatment of neovascular age-related macular degeneration (nAMD). The findings mark a significant advancement in non-invasive treatment options for retinal diseases traditionally managed through intravitreal injections.

A Novel Approach: siRNA Therapy via Eye Drops

SYL1801 is a small interfering RNA (siRNA) therapeutic designed to be administered via eye drops, aiming to reduce treatment burden associated with current injection-based therapies for nAMD. The phase 2a study, designated SYL1801_II, assessed the safety and efficacy of the topical formulation in treatment-naïve nAMD patients.

Study Design and Methodology

The phase 2a trial was a double-blind study that enrolled 99 subjects with treatment-naïve nAMD. Patients were divided into three parallel cohorts, each receiving a different dose level of SYL1801. The study evaluated outcomes over a 6-week period (42 days).

Primary Endpoint

The primary goal was to assess the change in Best Corrected Visual Acuity (BCVA) from baseline to the end of treatment. According to Sylentis, this endpoint was successfully achieved.

Key Findings

       • All three dose levels of SYL1801 were found to maintain visual acuity throughout the study period.

       • The middle dose concentration (25 mg/mh) demonstrated a statistically significant improvement in visual acuity at day 42.

       • Notably, over 71% of patients receiving the mid-dose maintained their visual acuity during the 6-week period.

These results suggest that SYL1801 may provide a non-invasive alternative to intravitreal injections, potentially improving compliance and patient experience in managing nAMD.

Industry Response and Future Outlook

Commenting on the study, Andreas Segerros, CEO of Sylentis, stated:

“With these data from this explorative study of SYL1801, we are encouraged to put efforts into the subsequent clinical research program with proper guidance from the patient outcomes in the concluded study.”

Presentation at ARVO 2025

The results of the phase 2a trial were shared in a scientific poster titled “AMD, Clinical Research” during the 2025 Association for Research in Vision and Ophthalmology (ARVO) annual meeting, held from May 4–8 in Salt Lake City.