07:58 AM EDT, 09/05/2025 (MT Newswires) -- Regenxbio ( RGNX ) said Friday that longer-term data from a phase I/II/III trial of clemidsogene lanparvovec, or RGX-121, further showed the ability of one-time treatment to improve outcomes for patients with Mucopolysaccharidosis Type II, or Hunter syndrome.

The company said it has submitted the 12-month data to the US Food and Drug Administration in response to an information request in an ongoing biologics license application review of RGX-121.

"The sustained reductions in CSF HS D2S6 and evidence of the strong correlation between biomarker level and neurodevelopmental improvement are highly encouraging as we look toward potential accelerated approval early next year," Regenxbio ( RGNX ) Chief Medical Officer Steve Pakola said.

The company's shares were up 3% in recent premarket activity.