REGENXBIO Inc. announced topline results from the Phase I/II/III CAMPSIITE®? trial of RGX-121 for the treatment of patients up to 5 years old diagnosed with Mucopolysaccharidosis Type II (MPS II), also known as Hunter syndrome, demonstrating that the pivotal phase of the trial met its primary endpoint with statistical significance. The results were presented at the 20th Annual WORLDSymposium??

by Paul Harmatz, M.D., UCSF Benioff Children's Hospital and trial investigator. As of January 3, 2024, RGX-121 continues to be well tolerated in 25 patients dosed across all phases of the CAMPSIITE trial. Following an RMAT meeting held with FDA at the end of 2023, REGENXBIO continues with plans to use CSF levels of D2S6 as a surrogate endpoint for accelerated approval and is completing remaining activities in order to file a BLA in the second half of 2024.

Based on an expected priority review, potential approval of the planned BLA could result in receipt of a Rare Pediatric Disease Priority Review Voucher in 2025.