Regenxbio maintains "Buy Rating" despite BLA review delay for RGX-121 in Hunter Syndrome

Regenxbio's BLA review for RGX-121 in Hunter Syndrome has been delayed. Despite this, the company remains a "buy rating" due to its promising pipeline and potential for future growth. The delay is expected to be resolved in the coming months.

Regenxbio Inc. (Nasdaq: RGNX) recently announced that the Biologics License Application (BLA) review for its potential one-time treatment, RGX-121, for Mucopolysaccharidosis Type II (MPS II), also known as Hunter syndrome, has been delayed. Despite this setback, the company maintains a "buy rating" due to its promising pipeline and potential for future growth.

RGX-121, a gene therapy treatment, is designed to deliver the iduronate-2-sulfatase (IDS) gene to the central nervous system (CNS). The treatment aims to provide a permanent source of secreted iduronate-2-sulfatase (I2S) protein beyond the blood-brain barrier, addressing the underlying genetic cause of Hunter syndrome. The FDA is expected to make a decision on the application by February 8, 2026.

The delay in the BLA review comes after the FDA completed a pre-license inspection and bioresearch monitoring information inspection for the RGX-121 BLA in August 2025, with no observations raised. No safety-related concerns have been reported during the BLA review, and RGX-121 has been well-tolerated in all 26 patients dosed across all phases of the CAMPSIITE trial as of August 20, 2024.

The company remains optimistic about the potential of RGX-121, citing positive data from the Phase I/II/III CAMPSIITE® trial. The trial demonstrated an 82% median reduction in cerebrospinal fluid (CSF) levels of heparan sulfate (HS) D2S6, a key biomarker of MPS II brain disease, sustained through one year. This reduction was strongly correlated with positive neurodevelopmental outcomes at one year.

Regenxbio's pipeline includes other gene therapy treatments for rare and retinal diseases, such as RGX-202 for Duchenne muscular dystrophy and RGX-111 for MPS I. The company's investigational gene therapies have the potential to change the way healthcare is delivered for millions of people.

The delay in the BLA review is expected to be resolved in the coming months, and Regenxbio remains focused on its mission to improve lives through the curative potential of gene therapy.

References:
[1] https://ir.regenxbio.com/news-releases/news-release-details/regenxbio-presents-positive-twelve-month-pivotal-data-phase