Taysha Gene Therapies, Inc. Q4 FY2024 earnings call

• Progress on TSHA-102 Phase 1/2 REVEAL trials with dosing of ten patients in Part A (dose escalation) complete. Both low and high doses showed encouraging safety profile with no treatment-related serious adverse events or dose-limiting toxicities. • Discussions with FDA via RMAT mechanism, with broad attendance from FDA across clinical, CMC, preclinical, etc. • Financials: R&D expenses $66M in 2024 vs $56.8M in 2023; G&A expenses $29M in 2024 vs $30M in 2023; net loss $89.3M in 2024 vs $111.6M in 2023; cash and cash equivalents $139M as of Dec 31, 2024. • Goal to advance TSHA-102 toward pivotal trial design focusing on functional gains in Rett syndrome domains.

No detailed product segment financial performance provided in the transcript. Focus is on the TSHA-102 gene therapy program.

• Expect to provide update on pivotal Part B trial design in first half of 2025. • Anticipate update on clinical data from low and high dose cohorts in REVEAL trials in first half of 2025. • Current cash resources expected to support operating expenses and capital requirements into Q4 2026.

• Risks that actual results may differ from forward-looking statements, including risks from clinical trial outcomes, FDA regulatory decisions, and potential impacts from external events like changes in FDA administration. • Uncertainties related to reproducibility and durability of favorable results from TSHA-102 clinical trials.

Q: Kristen Kluska asked about FDA interactions and number of people involved in discussions.

A: Sean Nolan said there are 15-20 FDA attendees in meetings, including Nicole Verdant, with consistent broad attendance and no impacts from new administration seen.

Q: Salveen Richter asked about FDA's view on endpoints and functional gains.

A: Sean Nolan said FDA discussions have been consistent, focusing on functional outcomes, and FDA has been open-minded, not guiding specific endpoints yet.

Q: Chris Raymond asked about differentiating factors of TSHA-102.

A: Sean Nolan mentioned self-complementary technology allowing quicker protein production, aiming for sooner and faster clinical effects, and plan to use natural history analysis for context.

Q: Maury Raycroft asked about safety past critical point.

A: Sukumar Nagendran said no treatment-related or DLTs of concern, mild LFT elevations controlled with prednisolone, and no other safety issues of concern.

Q: Yanan Zhu asked about closeness to endpoint agreement.

A: Sean Nolan said discussions are ongoing, with preference to align regulatory update with clinical data update in first half of 2025.

Q: Jack Allen asked about gatekeeping aspects for regulatory alignment and dosing safety.

A: Sean Nolan said discussions are ongoing, with recent sharing of natural history data, and Sukumar Nagendran noted mild liver enzyme elevations controlled by prednisone post-dosing with no acute toxicity concerns.

Q: Joon Lee asked about steroid suppression.

A: Sukumar Nagendran discussed standard steroid use and manageable liver enzyme elevations, with confidence in safety profile.