ROCKVILLE, Md., Dec. 8, 2020 /PRNewswire/ -- REGENXBIO Inc. (Nasdaq: RGNX), a leading clinical-stage biotechnology company seeking to improve lives through the curative potential of gene therapy based on its proprietary NAV® Technology Platform, today announced interim data from Cohorts 1 and 2 of the ongoing Phase I/II trial of RGX-121 for the treatment of patients up to 5 years old diagnosed with Mucopolysaccharidosis Type II (MPS II). In addition, REGENXBIO announced plans to evaluate a higher dose of RGX-121 in a third cohort of patients at an increased dose of 2.0x1011 GC/g brain mass. REGENXBIO expects to begin enrolling patients in Cohort 3 in the first quarter of 2021.