Previewing Some Thoughts Into TSHA's Upcoming Catalysts; Reiterating as a Top Pick

Research evidence excerpt

Previewing Some Thoughts Into TSHA's Upcoming Catalysts; Reiterating as a Top Pick

June 9, 2026

How Do We Cross-Compare NGNE (NC) and TSHA's Constructs/Therapies?

●Most investors we speak to have a clear view that intrathecal

administration will be viewed substantially more favorably than ICV

in a commercial world, by ease in performing/done in outpatient

setting, safety, more favorable reimbursement, etc.

●And importantly intrathecal administration doesn't come with an

efficacy trade off. Investors originally on the fence on this have started

to de-emphasize this debate now that TSHA has shown clear benefits

in the clinic.

●A more recent topic asked has been around construct differences. And

it's been our view that TSHA's double-stranded construct with a CNS-

specific promoter may allow for a rapid onset of action (more rapid

transcription of the transgene).

How to Cross-Compare Data Across NGNE (NC) and TSHA?

●Big picture, both company datasets have validated that AAV9-based

gene therapy is a successful treatment option for Rett syndrome.

●But cross-comparing data can be difficult for many reasons, and we

think investors should be understanding of several key differences.

●First on patient ages. We believe the strongest data to interpret is in

patients over the age of six where third party data suggests is the

earliest one can look at to remove any bias that some milestones/

improvements occur by chance (link to Cantor note).

●Next on the rigor of data collection where Taysha's includes clear

definitions of milestones, rigorous baseline collection, outside raters

adjudicating milestones, etc.

●We would note that Taysha also discloses additional skills and

improvements that are separate from the "milestones" but still carry