Atsena Therapeutics, a clinical-stage gene therapy company focused on bringing the life-changing power of genetic medicine to reverse or prevent blindness, today announced the first patient has been dosed in its phase 1/2 clinical trial, the LIGHTHOUSE study, evaluating subretinal injection of ATSN-201 for the treatment of X-linked retinoschisis (XLRS).
ATSN-201 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.
“Dosing the first patient in the LIGHTHOUSE study marks a significant milestone for Atsena and the XLRS community,” said Kenji Fujita, MD, CMO of Atsena Therapeutics. “We are excited to be utilizing AAV.SPR in the clinic, as it has the potential to revolutionize the treatment of XLRS, as well as other inherited retinal disorders. Spreading laterally beyond the subretinal injection site, AAV.SPR facilitates the safe delivery of RS1 to photoreceptors in the central retina/fovea. We look forward to advancing the LIGHTHOUSE study and the continued development of our novel gene therapies to reverse or prevent blindness.”
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 6-64 with a clinical diagnosis of XLRS caused by pathogenic or likely pathogenic mutations in RS1. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).
“Considering the lack of available therapies for X-linked retinoschisis, this is very exciting news for the inherited retinal disease community,” said Mark Pennesi, MD, PhD, professor in Ophthalmology and chief of the Paul H. Casey Ophthalmic Genetics Division Molecular and Medical Genetics, School of Medicine at Oregon Health & Science University (OHSU). “While attempts to deliver gene therapy through intravitreal routes faced challenges, subretinal treatment utilizing spreading AAV vectors has the potential to be the breakthrough we need to achieve efficacy.”
About x-linked retinoschisis (XLRS)
XLRS is a monogenic X-linked disease caused by mutations in the RS1 gene which encodes retinoschisin, a protein secreted primarily by photoreceptors. RS1 is localized to the extracellular surface of rods, cones, and bipolar cells. XLRS is characterized by schisis, or abnormal splitting of the layers of the retina, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss. XLRS primarily affects males and is typically diagnosed in early childhood. Approximately 30,000 males in the U.S. and EU have XLRS, for which there are currently no approved treatments.
About AAV.SPR
AAV.SPR, one of Atsena’s novel spreading capsids, spreads laterally beyond the subretinal injection site to enable safe and efficient transduction of the central retina (where schisis cavities predominate in XLRS patient retinas) when injected into areas outside the macula. A preclinical study in non-human primates demonstrated that AAV.SPR promotes transgene expression well beyond subretinal injection bleb margins. This is in stark contrast to benchmark vector AAV5, which remains confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and does not cause inflammation. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.