Atsena Initiates Dosing in Phase I/II XLRS Gene Therapy Trial

Atsena Therapeutics, a company dedicated to advancing genetic medicine for vision restoration, has commenced the second phase of the LIGHTHOUSE study. This Phase I/II clinical trial is assessing the subretinal administration of ATSN-201, a gene therapy candidate designed to treat X-linked retinoschisis (XLRS), a condition leading to progressive vision loss. ATSN-201 utilizes the innovative AAV.SPR spreading capsid, which facilitates gene expression in photoreceptors while minimizing surgical risks.

In the initial cohort of the trial, ATSN-201 demonstrated excellent tolerability among all three XLRS patients, with no serious adverse events being reported. The positive safety profile prompted the Data and Safety Monitoring Board to endorse the progression to the second cohort, where participants will receive an escalated dosage of ATSN-201.

Kenji Fujita, Atsena's Chief Medical Officer, expressed optimism regarding the safety and preliminary signs of structural and functional improvements observed in the LIGHTHOUSE study. He noted that the vector's lateral spread was successful, suggesting a promising step towards a potential one-time treatment for XLRS, a genetic disorder that typically emerges in childhood and can result in blindness.

The LIGHTHOUSE study is an open-label, dose-escalation, and dose-expansion trial targeting male patients aged six and above with XLRS. The condition is caused by mutations in the RS1 gene, which encodes retinoschisin, a protein vital for retinal health. XLRS is characterized by a schisis, or splitting of the retinal layers, leading to impaired vision and eventual blindness. It predominantly affects males, with approximately 30,000 affected individuals in the U.S. and EU, and currently, there are no approved treatments.

AAV.SPR, Atsena's novel capsid, is capable of lateral spread beyond the injection site, ensuring efficient transduction of the retina's central area. Preclinical studies in non-human primates have shown that AAV.SPR can promote gene expression significantly beyond the injection margins, unlike standard AAV vectors that remain confined. At clinically relevant doses, AAV.SPR effectively targets foveal cones without surgical detachment and avoids inflammation.

Atsena Therapeutics is in the clinical stage of development, focusing on creating superior treatments for inherited retinal diseases that can reverse or prevent blindness. The company's lead program involves ATSN-201 for XLRS, and another trial is evaluating ATSN-101 for Leber congenital amaurosis type 1 (LCA1), a common cause of childhood blindness. Atsena's pipeline is driven by novel AAV technology, addressing the unique challenges of inherited retinal diseases. The company is founded by leaders in ocular gene therapy and is led by a team committed to improving the lives of those with vision impairment.