Regenxbio’s RGX-121 shows efficacy in Phase 1/2/3 Hunter syndrome trial

Regenxbio announced positive results from the Phase I/II/III CAMPSIITE trial of RGX-121 for the treatment of patients with Mucopolysaccharidosis Type II, also known as Hunter syndrome. The totality of evidence from the CAMPSIITE trial continues to support RGX-121 as the potential first gene therapy and one-time treatment for MPS II. In the U.S. RGX-121 is also on track to be the first treatment that addresses the neurocognitive decline associated with MPS II, with the potential to be the first-line treatment for patients with neuronopathic disease. Patients receiving RGX-121 at the pivotal dose level demonstrated an 85% median reduction of cerebrospinal fluid levels of heparan sulfate D2S6, a key biomarker of brain disease activity, approaching normal levels and sustained for up to two years. Topline results presented earlier this year from the CAMPSIITE trial demonstrated that the pivotal phase of the trial met its primary endpoint with statistical significance. As of January 5, RGX-121 continues to be well tolerated in 25 patients dosed across all phases of the CAMPSIITE trial. Regenxbio is on track to initiate a rolling Biologics License Application submission using the accelerated approval pathway in Q3 using CSF D2S6 as a surrogate endpoint reasonable likely to predict clinical benefit. Approval of the planned BLA could result in receipt of a Priority Review Voucher in 2025.