Regenxbio completes dosing in Phase 1/2 trial of RGX-111 in MPS I

Regenxbio has completed dosing in the expanded Cohort 2 of the Phase I/II trial of RGX-111 for the treatment of severe Mucopolysaccharidosis Type I – MPS I -. The trial has now completed dosing, with eight patients enrolled across two dose cohorts. The primary endpoint of the trial is to evaluate the safety of RGX-111. Secondary and exploratory endpoints include biomarkers of IDUA enzyme activity in the cerebrospinal fluid, serum and urine, neurodevelopmental assessments, and caregiver reported outcomes. The Phase I/II trial of RGX-111 is a global trial, which includes sites in the U.S. and Brazil. Regenxbio plans to continue having early and frequent communication with regulatory agencies about pathways to expedite development of its neurodegenerative disease pipeline. In the first half of 2023, Regenxbio expects to use its Manufacturing Innovation Center to produce RGX-111 commercial-scale cGMP material from its proprietary, high-yielding suspension-based manufacturing process, named NAVXPress. The pivotal program for RGX-121 is using the NAVXPress manufacturing process. Additional interim data from the Phase I/II trial of RGX-111 is also expected to be reported in the first half of 2023.