Neurogene (NGNE) 3rd Annual Guggenheim Healthcare Innovation Conference summary

Trial results and enrollment

• Phase I/II data from 10 patients showed functional gains and global clinical improvement in every patient; all gained at least one milestone, 7/10 gained multiple milestones, and 7/10 had multi-domain change.

• At 12 months, 80% met the pivotal endpoint; benefits were seen across pediatric and adolescent ages and disease severities.

• Embolden enrolled 25 patients versus the planned 20, driven by strong patient interest; results are expected in H2 next year.

• DAYBUE is a symptom modifier; gene therapy is positioned to address Rett syndrome’s root cause.

Delivery and gene design

• Biodistribution studies found 10–100x greater delivery with ICV versus intrathecal lumbar administration; the one-time treatment strategy prioritizes brain delivery.

• Trial participants averaged 4.7 milestones, described as almost double the competitor’s result; delivery route was cited as a possible contributor.

• The single-stranded AAV9 construct carries full-length MECP2; expression starts by day 7 and reaches maximum in a couple of weeks, supporting stable protein expression and potential durability.

• Neurons remain available for treatment across ages; earlier treatment may better alter disease trajectory, while potential benefit was observed across age and severity ranges.

Regulatory and safety plans

• FDA discussions through the START program consistently supported 12-month data to assess durability; the pivotal endpoint is 12 months.

• BLA drafting has started, with a goal to move quickly through regulatory review after H2 next year data; 12-month outcomes are intended to support the label’s durability claims.

• No material HLH event was reported beyond the expected monitoring window following the last patient dosing in June.