05:41 PM EDT, 08/18/2025 (MT Newswires) -- Regenxbio ( RGNX ) said late Monday the US Food and Drug Administration has extended the review timeline of its Biologics License Application for RGX-121 to treat Mucopolysaccharidosis II, also known as Hunter syndrome.

The Prescription Drug User Fee Act goal date has been extended to Feb. 8, 2026 from Nov. 9, 2025, the company said.

The extension follows its submission of longer-term data for all patients in the pivotal study of RGX-121 in response to an FDA request, the firm said. It plans to present the data in September.