Atsena Advances Gene Therapy for XLRS

Atsena Therapeutics has announced the initiation of Part B of the LIGHTHOUSE study, a Phase 1/2 clinical trial evaluating the gene therapy ATSN-201 for the treatment of X-linked retinoschisis (XLRS). ATSN-201 utilizes AAV.SPR, a novel spreading capsid technology designed to deliver therapeutic gene expression to photoreceptors in the central retina while minimizing the surgical risks associated with foveal detachment.

Highlights from Part A

Part A of the LIGHTHOUSE study focused on assessing the safety and tolerability of three different doses of ATSN-201 administered via subretinal injection. Early data showed encouraging results:

• Functional and structural improvements in the retina validated the efficacy of the AAV.SPR spreading capsid.

• The Data Monitoring Committee recommended moving forward with Part B using a dose of 1.0E11 vg/mL, which offered an optimal balance of tolerability and efficacy.

Objectives and Structure of Part B

Part B is a multicenter clinical trial designed to evaluate nine additional adults and three pediatric patients with XLRS.

Cohorts and Trial Design

• Adult Cohort: Divided into three arms:

- Low volume treatment.

- High volume treatment.

- Control (off-therapy observation for one year with an option for treatment afterward).

• Pediatric Cohort: Dosing will occur after preliminary data from the adult cohort is analyzed.

Key Assessments

The trial will continue to assess the safety and efficacy of ATSN-201 through:

• Microperimetry

• Visual acuity

• Macular structure

Expert Perspectives

Patrick Ritschel, CEO of Atsena Therapeutics

“We are pleased to initiate Part B of the LIGHTHOUSE study of ATSN-201 following successful enrollment and dosing of Part A. The functional and structural improvements seen in Part A validate our novel AAV.SPR spreading capsid. Importantly, Part B will enroll both adult and pediatric participants. The Rare Pediatric Disease designation granted for ATSN-201 highlights the unmet need for a treatment, and we remain focused on advancing a therapeutic option for these patients.”

Kenji Fujita, MD, Chief Medical Officer

“A major benefit of ATSN-201 is that it does not need to be precisely placed underneath a specific retinal region. This gives surgeons more discretion regarding bleb placement during subretinal surgery and allows for safe delivery of the healthy gene to the critical portion of the retina. By testing different volumes in Part B, we will better understand the optimal administration of ATSN-201 to achieve the broadest effect.”

Unmet Need in X-Linked Retinoschisis

XLRS is a rare inherited retinal disease that primarily affects males and is typically diagnosed in early childhood. It is characterized by:

• Schisis: Abnormal splitting of retinal layers.

• Impaired visual acuity that cannot be corrected with glasses.

• Progressive vision loss leading to blindness.

Currently, there are no approved treatments for XLRS, which affects approximately 30,000 males in the US and EU.

About the LIGHTHOUSE Study

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 aged six and older with a clinical diagnosis of XLRS caused by pathogenic or likely pathogenic mutations in RS1.

• Enrollment: Ongoing.

• More Information: ClinicalTrials.gov (Identifier: NCT05878860).

Regulatory Designations

ATSN-201 has been granted Orphan Drug and Rare Pediatric Disease designations by the FDA, underscoring its potential to address the significant unmet medical need in XLRS.

Conclusion

With the initiation of Part B of the LIGHTHOUSE study, Atsena Therapeutics continues to make progress toward developing a groundbreaking gene therapy for XLRS. This innovative approach aims to provide a safe, effective treatment option for patients with this rare retinal disorder.