Benzinga | Feb 8, 2021 02:31PM EST

REGENXBIO Highlights Presentation Of Added Interim Data From Phase 1/2 Trial Of RGX-121 For Treatment Of Mucopolysaccharidosis Type II At 17th Annual WORLDSymposium 2021

REGENXBIO Inc. (NASDAQ:RGNX) today announced that additional positive interim data from a total of eight patients in 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), also known as Hunter Syndrome, will be presented at the 17th Annual WORLDSymposium(tm).

"We are pleased to report additional positive data from Cohorts 1 and 2 of our ongoing Phase I/II trial of RGX-121. Data from the eight patients dosed to date continue to show an encouraging safety profile of RGX-121, and highlight the potential of RGX-121 to restore biological enzyme activity and improve outcomes for MPS II patients," said Steve Pakola, M.D., Chief Medical Officer of REGENXBIO. "We look forward to enrolling patients in Cohort 3 at a higher dose level of RGX-121, which we expect to begin in the first quarter of 2021."

"The consistent biomarker data and neurocognitive development updates from patients in the RGX-121 trial are compelling, especially the data from patients who were not treated with enzyme replacement therapyprior to enrolling in the trial," said Dr. Roberto Giugliani, Professor, Department of Genetics, UFRGS, Medical Genetics Service, HCPA, Porto Alegre, Brazil. "These patients have demonstrated decreased levels of GAGs in urine, increased I2S enzyme in plasma, and one patient has shown reduced liver and spleen dimensions several months after receiving RGX-121, suggesting that RGX-121 delivered to the CNS has the potential to deliver benefit to patients outside of the CNS. I am encouraged by these results and look forward to further evaluations and advancement of this program."

RGX-121 is an investigational one-time gene therapy designed to deliver the gene that encodes the iduronate-2-sulfatase (I2S) enzyme using the AAV9 vector. RGX-121 is administered directly to the central nervous system (CNS). Patients in Cohorts 1 and 2 received doses of RGX-121 at 1.3x1010 genome copies per gram (GC/g) of brain mass and 6.5x1010 GC/g of brain mass, respectively. REGENXBIO expects to begin enrolling patients in Cohort 3 in the first quarter of 2021 at an increased dose of 2.0x1011 GC/g brain mass.

The study findings that will be presented at the WORLDSymposium are available under the Presentations & Publications page in the Media section of the company's website located at www.regenxbio.com.