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Atsena Therapeutics Announces Dosing Complete for Adults in Part B of the Phase I/II/III LIGHTHOUSE Trial Evaluating ATSN-201 to Treat X-linked Retinoschisis

Pediatric dosing expected to begin in Q4 2025

Pivotal cohort expected to begin enrolling in Q1 2026

BLA submission anticipated in early 2028

Part A results demonstrated efficacy and safety; ATSN-201 on track to be first gene therapy and one-time treatment for XLRS

DURHAM, NC, September 23, 2025 – Atsena Therapeutics, a clinical-stage gene therapy company focused on using the life-changing power of genetic medicine to reverse or prevent blindness, today announced that dosing is complete in adults enrolled in Part B of the LIGHTHOUSE study, the Phase I/II/III clinical trial evaluating subretinal injection of ATSN-201 for the treatment of X-linked retinoschisis (XLRS). Based on the evaluation of preliminary data from the adult cohort, dosing of the pediatric patients is expected to begin in the fourth quarter of 2025, pending approval from the Data Monitoring Committee.

“Dosing of adult patients in all groups of Part B is now complete, and follow-up is ongoing,” said Kenji Fujita, MD, Chief Medical Officer of Atsena Therapeutics. “Preliminary safety data remain favorable, and early structural and functional readouts, including improvements in foveal schisis and retinal sensitivity, are consistent with the positive signals observed in Part A. These findings will enable initiation of pediatric dosing, a critical next step in assessing the full therapeutic potential of ATSN-201 across the XLRS patient population.”

Part B of the ongoing multicenter clinical trial is evaluating a total of nine adults and three pediatric patients with XLRS. Adults are separated into three groups: low volume, high volume and control. Patients in the control group will be observed off-therapy for one year and then have the option to receive treatment. In July 2025, the U.S. Food and Drug Administration (FDA) agreed to the expansion of the study to serve as a pivotal trial and support a Biologics License Application (BLA), anticipated in early 2028.

“Completing adult dosing in Part B of the LIGHTHOUSE study represents a meaningful milestone as we advance ATSN-201 through the pivotal trial pathway,” said Patrick Ritschel, MBA, Chief Executive Officer of Atsena Therapeutics. “The FDA’s alignment on our trial design underscores the growing momentum behind this program. With no approved therapies, we remain committed to progressing this potential first- and best-in-class gene therapy as rapidly and rigorously as possible to patients with XLRS.”

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and ultimately blindness. 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 ATSN-201
ATSN-201 is Atsena’s investigational gene therapy leveraging AAV.SPR, a novel, laterally spreading capsid designed to efficiently target photoreceptors in the central retina while avoiding the surgical risks of foveal detachment. It is currently being evaluated in the Phase I/II/III LIGHTHOUSE Trial which consists of three parts (A, B and C) and six cohorts. The Phase I/II portion includes cohorts 1-3 (Part A) and cohorts 4-5 (Part B), while the remaining cohort 6 (Part C) will serve as the Phase III portion of the study.

ATSN-201 is the first XLRS gene therapy to demonstrate efficacy and positive safety data in a Phase I/II trial, with the majority of patients demonstrating improvements in retinal structure (foveal schisis closure) and meaningful improvements in retinal and visual function as assessed by microperimetry, best-corrected visual acuity and low-luminance visual acuity. ATSN-201 has demonstrated a favorable safety profile and has been well-tolerated for at least one year post-treatment with no serious adverse events reported to date. If approved, ATSN-201 will be the first gene therapy approved for XLRS. The best-in-class gene therapy product candidate has received Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease and Orphan Drug Designations from the U.S. Food and Drug Administration. Enrollment for this study is ongoing. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

About AAV.SPR
AAV.SPR, one of Atsena’s novel 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 contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II/III clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1) has completed a Phase I/II trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Announces Alignment with FDA on Regulatory Pathway to Approval for ATSN-201 in X-Linked Retinoschisis (XLRS)

Outcome of Regenerative Medicine Advanced Therapy (RMAT) meeting provides clear regulatory pathway to approval in a continuous Phase 1 / 2 / 3 study, avoiding the requirement for an additional registrational study and accelerating time to potential approval

Expansion builds on favorable efficacy and safety data from Part A of the LIGHTHOUSE study

Enrollment of pivotal cohort expected to begin in Q1 2026; BLA submission anticipated in early 2028

ATSN-201 on track to potentially be the first gene therapy and one-time treatment for XLRS

DURHAM, NC, July 9, 2025 – Atsena Therapeutics, a clinical-stage gene therapy company focused on using the life-changing power of genetic medicine to reverse or prevent blindness, today announced that the U.S. Food and Drug Administration (FDA) has agreed to the expansion of the company’s ongoing Phase 1 / 2 LIGHTHOUSE study of ATSN-201 into a continuous Phase 1 / 2 / 3 trial, enabling it to serve as a pivotal trial to support a Biologics License Application (BLA) submission for the treatment of X-linked retinoschisis (XLRS). The BLA submission is anticipated in early 2028.

“This regulatory milestone marks another significant step toward delivering a potentially first- and best-in-class gene therapy for patients living with XLRS,” said Patrick Ritschel, MBA, Chief Executive Officer of Atsena Therapeutics. “The agency’s agreement will expedite the clinical development of ATSN-201 by at least 1.5 years, compared to a separate Phase 3 clinical trial. If approved, this would be the first available treatment for XLRS, offering hope to patients and families affected by this inherited retinal disease. We’re grateful for the FDA’s continued guidance as we continue to advance this trial and prepare for filing a BLA in early 2028.”

The first- and best-in-class gene therapy product candidate has received Regenerative Medicine Advanced Therapy (RMAT), Fast Track, Rare Pediatric Disease and Orphan Drug Designations from the FDA. The regulatory feedback follows an RMAT meeting with the FDA. The Agency agreed on the proposed study design, endpoints and patient population to support potential registration. An additional cohort will be added to the ongoing multicenter trial. In the additional cohort, approximately 30 adult and pediatric patients will be randomized 1:1 between treatment and control groups. Patients in the control group will have the opportunity to receive treatment after one year. Efficacy and safety will be assessed in all patients using measures such as microperimetry, visual acuity and macular structure. The pivotal cohort is anticipated to begin enrolling in the first quarter of 2026 with a pivotal data readout expected in the second half of 2027.

“Data from the ongoing trial show that subretinal delivery of ATSN-201 has been well tolerated to date, including in patients with severe schisis cavities, and has led to encouraging improvements in both retinal structure and visual function,” said Kenji Fujita, MD, Chief Medical Officer of Atsena Therapeutics. “This program marks the first clinical use of our laterally spreading subretinal vector, offering important proof of principle for our ocular gene therapy platform. With the study’s expansion, we’re positioned to generate the pivotal data needed to potentially bring the first treatment for XLRS across the finish line.”

Currently, there are no approved treatments for XLRS, which is typically diagnosed in early childhood and affects approximately 30,000 males in the U.S. and the EU combined. The LIGHTHOUSE study is a dose-escalation and dose-expansion clinical trial in male patients ages six and older with a clinical diagnosis of XLRS caused by mutations in the RS1 gene. Enrollment for this study is ongoing. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and ultimately blindness. 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 ATSN-201
ATSN-201 is Atsena’s investigational gene therapy leveraging AAV.SPR, a novel laterally spreading capsid designed to efficiently target photoreceptors in the central retina while avoiding the surgical risks of foveal detachment. ATSN-201 is the first XLRS gene therapy to demonstrate efficacy and positive safety data in a Phase 1 / 2 trial. The majority of patients in Part A of the trial demonstrated improvements in retinal structure (foveal schisis closure) and meaningful improvements in retinal and visual function as assessed by microperimetry, best-corrected visual acuity and low-luminance visual acuity. ATSN-201 has demonstrated a favorable safety profile and has been well-tolerated up to one year post-treatment. No serious adverse events have been reported. If approved, ATSN-201 will be the first gene therapy approved for XLRS. The first and best-in-class gene therapy product candidate has received Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease and Orphan Drug Designations from the U.S. Food and Drug Administration.

About AAV.SPR
AAV.SPR, one of Atsena’s novel 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 contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase 1 / 2 / 3 clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1), has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Announces Positive Clinical Data from Part A of Phase I/II Trial Evaluating ATSN-201 Gene Therapy to Treat X-linked Retinoschisis (XLRS)

First XLRS study to demonstrate efficacy and positive safety data in a Phase I/II trial

Majority of patients demonstrated successful efficacy readouts across structural measurements (foveal schisis closure) and had meaningful improvement on visual function measurements including MP, BCVA, and LLVA

Safe and well-tolerated up to one year post-treatment

DURHAM, NC, May 19, 2025 – Atsena Therapeutics, a clinical-stage gene therapy company focused on using the life-changing power of genetic medicine to reverse or prevent blindness, today announced positive clinical data results from Part A of the LIGHTHOUSE study, a Phase I/II clinical trial 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. The best-in-class gene therapy product candidate has received Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease, and Orphan Drug Designations from the U.S. Food and Drug Administration.

“The full Part A data from the LIGHTHOUSE study reinforce the favorable safety profile and demonstrate encouraging structural and functional benefits across all three dose levels of ATSN-201,” said Kenji Fujita, MD, Chief Medical Officer of Atsena Therapeutics. “Interim data is available for nine adults who have been treated, and no serious adverse events related to treatment have been reported. We’re particularly pleased that the foveal schisis closure seen in 7 of 9 patients validates AAV.SPR’s ability to spread laterally beyond the subretinal injection blebs and enable safe gene delivery to the central retina. These findings represent a significant breakthrough, validating the use of our novel capsid to effectively treat inherited retinal disease and informing the safest and most effective path forward for Part B of the study, which is already underway. We look forward to advancing ATSN-201, which is on track to be the first gene therapy approved for XLRS.”

Part A of the study evaluated the tolerability and safety of three different doses of ATSN-201 administered through subretinal injection in three patients per cohort, for a total of nine adult patients. ATSN-201 was well tolerated in all nine patients with XLRS in Part A, and no serious adverse events related to treatment were reported. The majority of adverse events were related to the surgical procedure and were Grade 1-2 in severity. One serious adverse event, a fever of unknown origin with negative workup, occurred, which was unrelated to ATSN-201 or the surgical procedure. There were no dose-limiting toxicities, and no subjects discontinued from the study.

Efficacy highlights from the data include:

• Preliminary evidence of efficacy demonstrated at all dose levels
• 7 of 9 treated eyes had closure of foveal schisis, which was not demonstrated in untreated eyes
• On Microperimetry (MP), 67% of treated eyes (6/9) had an improvement of ≥ 7 dB in the 5 or more loci with the lowest sensitivity at baseline
• Statistically significant improvements were seen in Best Corrected Visual Acuity (BCVA) and Low Luminance Visual Acuity (LLVA)
• Structural improvements correlated with improvements in function

Enrollment is underway in Part B, a multicenter clinical trial that will evaluate nine additional adults and three pediatric patients with XLRS. The adult cohort will be broken down into three arms: low volume, high volume, and control (deferred treatment). Patients in the control arm will be observed for one year and then have the option to receive treatment. The pediatric cohort will be dosed after evaluating preliminary data from the adult cohort in Part B. This part of the study will continue to assess safety and efficacy, including microperimetry, visual acuity, and macular structure.

“We’re proud to share these clinical data that demonstrate ATSN-201 can be safely delivered subretinally in patients with extensive retinal schisis—a pivotal milestone for our XLRS program,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “These data underscore the promise of our novel spreading capsid and the urgency of addressing a devastating disease with no approved therapeutic solutions. We remain deeply committed to advancing gene therapies that can transform the lives of individuals living with XLRS and other inherited retinal diseases.”

Currently, there are no approved treatments for XLRS, which is typically diagnosed in early childhood and affects approximately 30,000 males in the U.S. and the EU combined. The LIGHTHOUSE study is a dose-escalation and dose-expansion clinical trial in male patients ages six and older with a clinical diagnosis of XLRS caused by mutations in the RS1 gene. Enrollment for this study is ongoing. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

Interim results from Part A of the study were presented at the 2025 Association for Research in Vision and Ophthalmology and 2025 American Society for Gene and Cell Therapy annual meetings. Presentations can be found on the Presentations and Publications page of the Atsena website at www.atsenatx.com/news/presentations-and-publications.

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and ultimately blindness. 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 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 contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1) has completed a Phase I/II trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics to Present at May Scientific Conferences

DURHAM, NC, April 29, 2025 – Atsena Therapeutics, a clinical-stage gene therapy company focused on using the life-changing power of genetic medicine to reverse or prevent blindness, today announced it will present at the following scientific conferences in May:

Retinal Therapeutics Innovation Summit 2025 – Salt Lake City, UT
Session: Retinal Genetic Augmentation
Date and Time: Friday, May 2, 2025, 3:30-3:45 p.m. MT
Presentation Title: Advancements in IRD Gene Therapy: From the Bench to the Clinic
Presenter: Kenji Fujita, MD, Chief Medical Officer, Atsena Therapeutics

ARVO 2025 Symposium – Salt Lake City, UT
Session: Innovating Breakthroughs in Ocular Gene Therapy
Presentation Date and Time: Thursday, May 8, 2025, 8:51-9:09 a.m. MT
Presentation Title: Interim safety and efficacy data in XLRS patients validates the use of a novel, laterally spreading capsid for the treatment of retinal disease
Presenter: Lesley Everett, MD, PhD, Assistant Professor, Ophthalmology, Oregon Health & Science University

Poster Session: Retinal Function Testing and Advanced Therapies
Presentation Date and Time: Thursday, May 8, 2025, 2:00-3:45 p.m. MT
Posterboard Number: A0499
Poster Title: Quantitative Comparison of Two Physical Mobility Tests as Functions of FST and BCVA to Evaluate Therapeutic Benefit in LCA1 Patients Treated with Unilateral Gene Therapy
Presenter: Alexandra Viviann Garafalo, Research Project Manager, Perelman School of Medicine, University of Pennsylvania

American Society of Gene and Cell Therapy (ASGCT) 28th Annual Meeting – New Orleans and Virtual
Session: Gene Therapy Trials – In-Vivo Gene Therapy Modification
Date and Time: Friday, May 16th, 2025, 5:15 p.m. ET
Presentation Title: Safety and Efficacy of ATSN-201 Dose Escalation in Patients with X-linked Retinoschisis (XLRS)
Presenter: Shannon Boye, PhD, Founder and Chief Scientific Officer, Atsena Therapeutics

3rd Annual Retinal Imaging Biomarkers & Endpoints Summit – Boston, MA
Session: Delving into Commercial Trends, Trial Insights, and Therapeutic Applications to Spearhead Development
Date and Time: Thursday, May 29, 2025, 2:30 p.m. ET
Presentation Title: Delving Into Emerging Insights for Trial Endpoints: Analyzing Correlations Between FST & MLMT
Presenter: Kenji Fujita, MD, Chief Medical Officer, Atsena Therapeutics

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and ultimately blindness. 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 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 contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1) has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Granted U.S. FDA Regenerative Medicine Advanced Therapy Designation for ATSN-201 Gene Therapy to Treat X-linked Retinoschisis

Marks fourth FDA designation for ATSN-201, which has also received Fast Track, Rare Pediatric Disease and Orphan Drug Designations

DURHAM, NC, April 15, 2025 – Atsena Therapeutics, a clinical-stage gene therapy company focused on using the life-changing power of genetic medicine to reverse or prevent blindness, today announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation for 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.

“We’re honored that the FDA has granted Regenerative Medicine Advanced Therapy (RMAT) designation to ATSN-201, further underscoring its potential to address the urgent, unmet need in XLRS—a rare inherited retinal disease with no approved treatments,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “This regulatory momentum, coupled with the recent close of our oversubscribed $150 million Series C financing, reinforces our commitment to advancing meaningful gene therapies that have the potential to improve vision and quality of life for individuals living with XLRS and other inherited retinal diseases.”

Established under the 21st Century Cures Act, RMAT designation is a dedicated program designed to expedite the drug development and review processes for promising pipeline products, including gene therapies. A regenerative medicine therapy is eligible for RMAT designation if it is intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug or therapy has the potential to address unmet medical needs for that disease or condition. RMAT designation provides sponsors with intensive FDA guidance on efficient drug development, including the ability to discuss surrogate or intermediate endpoints, potential ways to support accelerated approval and satisfy post-approval requirements, potential priority review of the biologics license application (BLA), and other opportunities to expedite development and review.
Currently, there are no approved treatments for XLRS, which is typically diagnosed in early childhood and affects approximately 30,000 males in the U.S. and the EU. The safety and tolerability of ATSN-201 is currently being evaluated in the LIGHTHOUSE study, a Phase I/II, dose-escalation and dose-expansion clinical trial in male patients ages six and older with a clinical diagnosis of XLRS caused by mutations in the RS1 gene. Enrollment for this study is ongoing. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and ultimately blindness. 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 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 contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1) has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Announces Oversubscribed $150 Million Series C Financing to Further Advance Ocular Gene Therapy Programs

Financing led by new investor Bain Capital with participation from new investor Wellington Management and all existing investors

Proceeds to support advancement of ATSN-201 through potential approval and launch as well as preclinical programs to treat inherited retinal diseases

Norbert Riedel, PhD, will join Atsena’s Board of Directors

DURHAM, NC, April 2, 2025 – Atsena Therapeutics (“Atsena” or “the Company”), a clinical-stage gene therapy company focused on bringing the life-changing power of genetic medicine to reverse or prevent blindness, today announced the successful close of an oversubscribed $150 million Series C financing. The financing was led by Bain Capital’s Life Sciences team, with participation from an additional new investor, Wellington Management. All the Company’s existing investors also participated in the round, including Lightstone Ventures, Sofinnova Investments, Abingworth, Foundation Fighting Blindness, Hatteras Venture Partners, Osage University Partners, and the Manning Family Foundation.

Proceeds from the financing will be used to advance Atsena’s lead program, ATSN-201, for the treatment of X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. The proceeds will also support Atsena’s preclinical pipeline of first-in-class therapies and expand the use of Atsena’s novel spreading AAV.SPR capsid.

“Closing our Series C marks a pivotal moment for Atsena as we advance our transformative ocular gene therapies and fuel our next phase of growth, innovation, and clinical progress,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “It follows a productive 12 months of key achievements including securing a partner to advance ATSN-101 to a global pivotal trial for Leber Congenital Amaurosis type 1 (LCA1) and initiating Part B of the ATSN-201 LIGHTHOUSE study for XLRS. We’re grateful for the support of our investors and partners who share our vision for the future of leveraging genetic medicine to reverse or prevent blindness.”

To date, Atsena’s clinical portfolio has received multiple designations by the U.S. Food and Drug Administration (FDA). ATSN-101, for the treatment of LCA1, has received Rare Pediatric Disease designation, Orphan Drug Designation, and Regenerative Medicine Advanced Therapy designation. ATSN-201 has been granted Fast Track, Rare Pediatric Disease, and Orphan Drug Designations. Updated data from the ongoing LIGHTHOUSE Phase I/II clinical trial evaluating ATSN-201 is anticipated later this year.

“We believe Atsena has a unique opportunity to deliver meaningful impact for patients with inherited retinal diseases on the basis of novel science and impressive clinical data generated to date,” said Amir Zamani, a Partner at Bain Capital. “We look forward to supporting Patrick and his strong team as they look to unlock the next phase of Atsena’s growth and innovation while thoughtfully advancing potentially groundbreaking therapies toward patients in need.”

In conjunction with the financing, Norbert Riedel, PhD, a seasoned scientist and biopharmaceutical executive, will join Atsena’s Board of Directors.

Wedbush & Co. served as exclusive placement agent to Atsena for the Series C financing, Cooley LLP acted as its legal advisor.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1) has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Granted U.S. FDA Fast Track Designation for ATSN-201 Gene Therapy to Treat X-linked Retinoschisis

Marks third FDA designation for ATSN-201, which has also received Rare Pediatric Disease Designation and Orphan Drug Designation

DURHAM, NC, March 12, 2025 – Atsena Therapeutics, a clinical-stage gene therapy company focused on using the life-changing power of genetic medicine to reverse or prevent blindness, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation for 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.

“We are pleased that the FDA has granted Fast Track designation to ATSN-201, reinforcing its potential to address the significant unmet need in XLRS, a rare inherited retinal disease with no approved treatments,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “This designation, along with the previously granted Orphan Drug and Rare Pediatric Disease designations, marks an important milestone in advancing the development of ATSN-201. The Atsena team remains dedicated to developing transformative gene therapies and improving the quality of life of individuals suffering from XLRS and other inherited retinal diseases.”

Fast Track designation is granted to treatments intended to address serious or life-threatening diseases that have demonstrated the potential to meet an unmet medical need. Treatments that receive Fast Track designation may benefit from more frequent interactions with the FDA throughout drug development. In addition, the Fast Track program allows for Priority Review, if relevant criteria are met.

Currently, there are no approved treatments for XLRS, which is typically diagnosed in early childhood and affects approximately 30,000 males in the U.S. and the EU. The safety and tolerability of ATSN-201 is currently being evaluated in the LIGHTHOUSE study, a Phase I/II, dose-escalation and dose-expansion clinical trial in male patients ages six and older with a clinical diagnosis of XLRS caused by mutations in the RS1 gene. Enrollment for this study is ongoing. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and ultimately blindness. 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 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 contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1), one of the most common causes of blindness in children, has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

Media Contact:
Gina Mangiaracina
6 Degrees
(917) 797-7904
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics to Present ATSN-201 Safety and Efficacy Data at The Macula Society’s 48th Annual Meeting

 

DURHAM, NC, February 6, 2025 – 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 that safety and efficacy data on ATSN-201 for the treatment of X-linked retinoschisis (XLRS) will be presented during a panel discussion at The Macula Society’s 48^th Annual Meeting taking place February 12-15, 2025, in Charlotte Harbor, Florida. 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.

Presentation details are as follows:

Session: Inherited Retinal Dystrophy I: Trials

Date and Time: Thursday, February 13, 2025, 7:00-7:45 a.m. ET

Presentation Title: Interim Safety and Efficacy of ATSN-201 Dose Escalation Study in Patients With X-linked Retinoschisis (XLRS)

Presentation Time: 7:25 a.m. ET

Presenter: Christine Nichols Kay, MD, Clinical Ophthalmology Advisor, Atsena Therapeutics

The LIGHTHOUSE study is a Phase I/II, open-label, dose-escalation and dose-expansion clinical trial evaluating the safety and tolerability of ATSN-201 in male patients ages six 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 U.S. Food and Drug Administration.

 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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and ultimately blindness. 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 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 AAV vectors, which remain 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/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1), one of the most common causes of blindness in children, has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

 

Media Contact:
Gina Mangiaracina

6 Degrees
(917) 797-7904

[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Initiates Part B of Phase I/II Clinical Trial Evaluating Gene Therapy ATSN-201 to Treat X-linked Retinoschisis

Part B of the LIGHTHOUSE study will enroll adults and children

 DURHAM, NC, January 8, 2025 – 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 initiation of Part B of the LIGHTHOUSE study, a Phase I/II 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.

“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,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “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.”

Part A of the study evaluated the safety and tolerability of three different doses of ATSN-201 administered through subretinal injection. After reviewing early safety data from Part A, the Data Monitoring Committee has recommended proceeding to Part B using 1.0E11 vg/mL, a concentration that offered the optimal balance of tolerability and efficacy based on preliminary clinical results. Part B is a multicenter clinical trial that will evaluate nine additional adults and three pediatric patients with XLRS. The adult cohort will be broken down into three arms, low volume, high volume and control. Patients in the control arm will be observed off-therapy for one year and then have the option to receive treatment. The pediatric cohort will be dosed after evaluating preliminary data from the adult cohort in Part B. This part of the study will continue to assess safety and efficacy, including microperimetry, visual acuity and macular structure.

“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,” said Kenji Fujita, MD, Atsena’s Chief Medical Officer. “By testing different volumes in Part B, we will better understand the optimal administration of ATSN-201 to achieve the broadest effect.”

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 U.S. and EU have this inherited retinal disease.

The LIGHTHOUSE study is a Phase I/II, open-label, dose-escalation and dose-expansion clinical trial evaluating the safety and tolerability of ATSN-201 in male patients ages six 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 U.S. Food and Drug Administration.

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and ultimately blindness. 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 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 AAV vectors, which remain 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/.

About Atsena Therapeutics
Atsena Therapeutics (“Atsena”) is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s first-in-class, investigational gene therapy for Leber congenital amaurosis type 1 (LCA1), one of the most common causes of blindness in children, has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8). Atsena is advancing ATSN-101 toward the initiation of a global pivotal trial as part of an exclusive, strategic collaboration. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit https://atsenatx.com/.

 

Media Contact:
Tony Plohoros
6 Degrees
(908) 591-2839
[email protected]

Business Contact:
[email protected]

Atsena Therapeutics Announces Dosing Completed in Part A of Phase I/II Clinical Trial Evaluating Gene Therapy ATSN-201 to Treat X-linked Retinoschisis

 

DURHAM, NC, December 16, 2024 – 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 dosing has been completed in Part A of the LIGHTHOUSE study, a Phase I/II 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,” said Kenji Fujita, MD, Atsena’s Chief Medical Officer. “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 U.S. and EU have this inherited retinal disease.

“We are thrilled that dosing is complete in Part A of the LIGHTHOUSE study for ATSN-201 and that we’ve begun hearing positive anecdotes from those involved. This marks a significant milestone for patients with XLRS as we push to bring a therapeutic option to individuals that otherwise have no approved treatment,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “It also represents potential for individuals living with other inherited retinal diseases that could benefit from our novel capsid. We look forward to the insights gained from this trial as we pioneer new approaches to ocular gene therapy.”

The LIGHTHOUSE study is a Phase I/II, open-label, dose-escalation and dose-expansion clinical trial evaluating the safety and tolerability of ATSN-201 in male patients ages six 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 U.S. Food and Drug Administration.

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 retinal layers, which causes impaired visual acuity that is not correctable with glasses and, ultimately, blindness. 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 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 AAV vectors, which remain 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/.

About Atsena Therapeutics
Atsena Therapeutics is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in an ongoing Phase I/II clinical trial for X-linked retinoschisis (XLRS), a genetic condition that is typically diagnosed in childhood and leads to blindness later in life. ATSN-101, Atsena’s program for Leber congenital amaurosis type 1 (LCA1), one of the most common causes of blindness in children, has completed a Phase 1 / 2 trial with positive results (https://doi.org/10.1016/s0140-6736(24)01447-8) and is moving towards initiation of a pivotal trial. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, please visit  https://atsenatx.com/.

 

Media Contact:
Tony Plohoros
6 Degrees
(908) 591-2839
[email protected]

Business Contact:
[email protected]