Atsena Completes Dosing in Part A of Phase 1/2 Trial Evaluating Gene Therapy to Treat X-linked Retinoschisis

Atsena Therapeutics announced dosing has been completed in Part A of the LIGHTHOUSE study, a phase 1/2 clinical trial evaluating subretinal injection of ATSN-201 for the treatment of X-linked retinoschisis (XLRS). ATSN-201, a best-in-class gene therapy product candidate, leverages AAV.SPR, the company’s novel spreading capsid, to achieve therapeutic levels of gene expression in photoreceptors of the central retina while avoiding the surgical risks of foveal detachment.

“Nine adults have been treated in Part A of the study in which three dose levels of ATSN-201 are being evaluated for safety and efficacy. We have seen both structural and functional benefits in patients treated at all dose levels. Additionally, no serious adverse events related to treatment have been reported,” Kenji Fujita, MD, Atsena’s Chief Medical Officer, said in a company news release. “Collecting data from Part A of the trial is an important breakthrough for Atsena because it validates the use of our novel capsid to effectively treat inherited retinal disease and it informs the safest and most effective path forward for Part B. We look forward to providing further updates from those patients early next year.”

Currently, there are no approved treatments for XLRS which is typically diagnosed in early childhood and primarily affects males. XLRS is characterized by schisis, or abnormal splitting of retinal layers, which causes impaired visual acuity that is not correctable with glasses and ultimately leads to blindness. Approximately 30,000 males in the US and EU have this inherited retinal disease.

The LIGHTHOUSE study is a phase 1/2, open-label, dose-escalation and dose-expansion clinical trial evaluating the safety and tolerability of ATSN-201 in male patients ages 6 and older with a clinical diagnosis of XLRS caused by pathogenic or likely pathogenic mutations in RS1. Enrollment for this study is ongoing.

For more information, visit ClinicalTrials.gov (Identifier: NCT05878860). ATSN-201 has received Orphan Drug and Rare Pediatric Disease designations from the FDA.