Regenxbio (RGNX) investor relations material

Regulatory strategy and timelines

• Plans to initiate rolling BLA filing for Duchenne gene therapy in Q3 this year, aiming for completion in Q1 2027 and approval within 2027.

• Waiting for FDA leadership stabilization before key regulatory submissions, viewing recent changes as positive for rare disease therapies.

• Engaged in ongoing discussions with FDA and EMEA, with a confirmatory study nearly fully enrolled and an ex-U.S. RCT planned.

• Confident that current data supports accelerated approval, with robust magnitude of effect and strong biomarker correlation.

• Patient advocacy groups are actively pushing for regulatory agencies to expedite access to new therapies.

Clinical data and safety

• Top-line data for Duchenne gene therapy shows strong microdystrophin expression and functional benefit, with ongoing accrual of 12-month functional data.

• Safety profile includes two SAEs (liver injury and myocarditis) in 30 patients, both resolved without sequelae and at lower rates than comparable therapies.

• Functional improvements observed in several patients, including those eight years and older, exceeding expectations of stabilization.

• Product is differentiated by its construct, with FDA recognizing its uniqueness compared to competitors.

• Prophylactic regimen using steroids, eculizumab, and sarilumab is considered manageable and well-accepted by investigators.

Competitive landscape and differentiation

• Uptake of existing commercial gene therapies has been slower than anticipated, with safety and functional benefit as key concerns for patients.

• Differentiation includes in-house U.S. manufacturing, high product purity, and attractive cost of goods, supporting rapid BLA progress.

• Product design includes the C terminus domain, contrasting with competitors' molecular approaches.