Taysha Gene Therapies (TSHA) investor relations material

Executive summary

• Achieved significant milestones in 2025, including compelling REVEAL phase I/II data for TSHA-102 in Rett syndrome and FDA Breakthrough Therapy designation.

• Dosed multiple Rett syndrome patients in pivotal REVEAL trial, with enrollment progressing and dosing completion expected in Q2 2026; ASPIRE trial for younger patients also cleared by FDA and on track for Q2 2026.

• Maintained favorable safety profile for TSHA-102, with no treatment-related serious adverse events or dose-limiting toxicities as of March 2026.

• Achieved written FDA alignment on pivotal and ASPIRE trial designs, manufacturing, and comparability strategy, supporting a streamlined BLA submission.

• Advanced commercial readiness with key leadership hires and market research indicating strong anticipated demand.

Financial highlights

• Research and development expenses rose to $86.4M for 2025, up from $66M in 2024, driven by increased headcount and clinical activities.

• General and administrative expenses increased to $33.9M from $29M, mainly due to higher compensation, legal, and professional fees.

• Net loss for 2025 was $109M ($0.34/share), compared to $89.3M ($0.36/share) in 2024.

• Ended 2025 with $319.8M in cash and cash equivalents; raised $50M in Q4 via ATM equity offering.

• Current cash resources expected to fund operations into 2028.

Outlook and guidance

• On track to complete dosing in both pivotal REVEAL and ASPIRE trials by Q2 2026.

• Expect to report 12-month follow-up data for all 12 REVEAL Part A patients in Q2 2026.

• BLA-enabling PPQ manufacturing lots to be completed by end of 2026; commercial manufacturing process initiation expected in Q2 2026.

• BLA submission timing contingent on FDA feedback post-interim analysis; could proceed after six-month data if agency agrees.

• Proceeds from recent equity raise intended to support potential commercial inventory build in 2027.