Company: RGNX
Filing Date: 2025-03-13
Form Type: 10-K
Source: 0000950170-25-038770
Chunk: 301

Company: REGENXBIO Inc.
Filing Date: 2025-03-13
Form: 10-K
Item: Item 7
Chunk 301
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 is to evaluate the prevalence of AAV8 antibodies in patients with Duchenne up to 12 years of age. Information collected in this study may be used to identify potential participants for the AFFINITY DUCHENNE trial and potential future trials of RGX-202.

•RGX-121: We are developing RGX-121 (clemidsogene lanparvovec) in collaboration with Nippon Shinyaku in the United States and certain countries in Asia as an investigational one-time AAV therapeutic for the treatment of Mucopolysaccharidosis Type II (MPS II), also known as Hunter syndrome, using the NAV AAV9 vector to deliver the gene that encodes the iduronate-2-sulfatase enzyme.

In the pivotal phase of the Phase I/II/III CAMPSIITE® trial, RGX-121 achieved its primary endpoint, a reduction in cerebrospinal fluid Heparan sulfate levels of D2S6, a biomarker indicative of brain disease activity, with statistical significance. In September 2024, we announced positive data from the pivotal dose level of RGX-121 demonstrating long-term systemic effect. We plan to use levels of cerebrospinal fluid Heparan sulfate D2S6 as a surrogate endpoint reasonably likely to predict clinical benefit for accelerated approval. A BLA for RGX-121 seeking accelerated approval was submitted to the FDA in March 2025, which we believe is likely to be eligible for priority review. We expect potential approval of RGX-121 in the second half of 2025.

Potential approval of the BLA for RGX-121 could result in receipt of a Rare Pediatric Disease Priority Review Voucher in 2025, assuming the statutory criteria are met. If approved, RGX-121 would be the first approved gene therapy and one-time treatment for MPS II.

•RGX-111: We are developing RGX-111 in collaboration with Nippon Shinyaku in the United States and certain countries in Asia as an investigational one-time AAV therapeutic for the treatment of Mucopolysaccharidosis Type I (MPS I), also known as Hurler syndrome, using the NAV AAV9 vector to deliver the IDUA gene.  

In November 2023, future development of RGX-111 was halted as a result of a strategic pipeline prioritization and corporate restructuring. Prior to that announcement, RGX-111 was demonstrated to be well tolerated and