Atsena Therapeutics announced the US 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, the company said in a press release. 

The 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, the company relayed in the press release. 

Atsena Therapeutics said 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 1 year.

According to the company, 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.

The LIGHTHOUSE study is a dose-escalation and dose-expansion clinical trial in male patients ages 6 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 https://clinicaltrials.gov/search?term=NCT05878860.