REGENXBIO Inc.

In 2009, we acquired exclusive rights to our NAV Technology Platform. Our NAV Technology Platform includes over 100 NAV Vectors, as well as vectors that are at least 95% identical to any NAV Vector, that provide the foundation for the development of new AAV therapeutics. We have observed that several of our NAV Vectors demonstrate preferential tropisms for a range of tissues, as well as efficient transgene delivery and expression that may produce a therapeutic effect. Our NAV Technology Platform has enabled the development of a number of gene therapies being investigated in clinical trials and two that are FDA-approved.

For many years, by sublicensing NAV Vectors from our NAV Technology Platform to other biopharmaceutical companies with disease-specific expertise, which we refer to as our NAV Technology Licensees, we received capital to advance our own research and capabilities. Our NAV Technology Platform is being applied to a number of programs over a broad range of therapeutic areas and disease indications by our NAV Technology Licensees. These partnered programs include Novartis’ Zolgensma® and Itvisma® gene therapies for the treatment of spinal muscular atrophy (SMA), a debilitating and potentially deadly disease. Zolgensma was approved by the U.S. Food and Drug Administration (FDA) in 2019 for the treatment of SMA in patients under the age of two years old, and Itvisma was approved by the FDA in November 2025 for the treatment of SMA in patients two years and older. Together, Zolgensma and Itvisma have been used to treat thousands of patients suffering from SMA. Our partnering strategy provides us the flexibility to sublicense development of treatments designed to address significant unmet medical needs, while remaining focused on our own pipeline of gene therapies.

We believe we have extensive human safety experience to support the development of our investigational AAV therapeutics based on data from thousands of patients dosed with AAV therapeutics derived from our NAV Technology Platform in two FDA approved products and numerous clinical stage programs. To date, we have observed that AAV therapeutics derived from our NAV Technology Platform have been generally well tolerated.