Atsena Therapeutics present positive clinical data for LCA1 gene therapy program
Astena Theraputics' investigational gene therapy, ATSN-101, has shown promising long-term results in an early clinical trial for LCA1, a sever inherited retinal disease caused by mutations in the GUCY2D gene.
LCA1 is a severe inherited retinal disease caused by mutations in the GUCY2D gene, leading to significant vision loss. There are currently no approved treatments. ATSN-101 is an experimental gene therapy developed by Atsena Therapeutics that uses a harmless virus to deliver a healthy copy of the GUCY2D gene directly to retinal cells, with the aim of restoring normal gene function and improving vision. In an ongoing phase 1/2 clinical trial, ATSN-101 has shown encouraging results. Participants receiving the highest dose experienced substantial and lasting improvements in light sensitivity that were maintained for at least three years after treatment. The therapy has also been well tolerated, with no treatment-related serious adverse events reported. Based on these positive findings, Atsena plans to begin a global pivotal phase 3 trial in the second half of 2026
What is LCA1?
Leber Congenital Amaurosis (LCA) is a rare genetic eye disease that appears at birth or in the first few months of life. The extent of vision loss varies between individuals but is generally more rapid and severe than other forms of retinal disease. LCA is actually a term given to a group of diseases that are caused by mutations in at least 25 genes. LCA1 is one of the most common forms of LCA, affecting approximately 20 percent of people who live with this group of inherited retinal diseases (IRDs).
LCA1 is caused by mutations in the GUCY2D gene. Mutations in the GUCY2D gene lead to the disruption of a protein called retinal guanylate cyclase-1 (GC1), an essential protein for normal photoreceptor function in the retina. In healthy eyes, GC1 helps to produce a molecule called cGMP, which is needed for photoreceptors to recover after detecting light and to continue sending visual signals to the brain. Without enough cGMP, the normal visual signalling process (phototransduction) is disrupted. As a result, photoreceptors are unable to respond to light properly, leading to severe visual impairment.
There are no approved treatments for LCA1 currently, however given the severity of the condition, it is one of the most extensively researched IRDs, and a number of clinical trials are underway such as the one by Atsena Therapeutics.
The treatment:
Atsena Therapeutics have developed a treatment known as ATSN-101, which is currently being tested in a phase 1/2 clinical trial.
ATSN-101 is an adeno-associated viral vector gene therapy, meaning that a small virus, that doesn’t cause illness in humans, is used as a delivery system to package and transport a healthy copy of the GUCY2D gene into cells to alter the genetic material. ATSN-101 is delivered via a single subretinal injection. Subretinal injection involves delivering the gene therapy directly under the retina into the subretinal space, where the therapeutic agent can make direct contact with photoreceptors
The trial:
This phase 1/2 clinical trial is designed to evaluate the safety, tolerability and efficacy of ascending doses of ATSN-101 administered as a unilateral subretinal injection. The trial is taking place across 2 sites in the US, and although active, has now closed recruitment.
Updates:
Atsena Therapeutics recently presented 3-year safety and efficacy results from part A of the phase 1/2 trial involving 15 participants. They found that:
- Participants treated at the high dose continued to demonstrate clinically meaningful improvements in dark-adapted full-field stimulus testing (FST), with a mean improvement of approximately 20 decibels, a 100-fold gain in light sensitivity, that has been durable through at least three years post-treatment.
- ATSN-101 was well-tolerated with no drug-related serious adverse events and no participant discontinuations.
Atsena expects to initiate a global pivotal phase 3 trial for ATSN-101 in the second half of 2026 and we look forward to hearing updates about this soon!
To learn more about Atsena Therapeutics or ATSN-101, please visit their website here.