Exhibit 99.1 Initial data from cohort one (low dose, 5.7x1014 total vg) in REVEAL pediatric trial expected mid-2024; initial data from cohort two (high dose, 1x1015 total vg) in both trials (adolescent/adult and pediatric) expected in 2H 2024 Conference call and live webcast today at 4:30 PM Eastern Time Dallas – March 19, 2024 – Taysha Gene Therapies, Inc. (Nasdaq: TSHA) (Taysha or the Company), a clinical-stage gene therapy company focused on developing and commercializing AAV-based gene therapies for the ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________ to ___________ Commission File Number: 001-39536 Taysha Gene Therapies, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 84-3199512 ( ...

Taysha Gene Therapies, Inc. (NASDAQ:TSHA) Q3 2023 Results Conference Call November 14, 2023 4:30 PM ET Company Participants Hayleigh Collins - Director and Head of Corporate Communications Sean Nolan - Chief Executive Officer Sukumar Nagendran - President and Head of Research and Development Kamran Alam - Chief Financial Officer Conference Call Participants Whitney Ijem - Canaccord Genuity Kristen Kluska - Cantor Fitzgerald Salveen Richter - Goldman Sachs Gil Blum - Needham & Co Yanan Zhu - Wells Fargo Secu ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________ to ___________ Commission File Number: 001-39536 Taysha Gene Therapies, Inc. Indicate by check mark whether the registrant has submitted electro ...

Financial Performance - The company reported a net loss of $42.2 million for the six months ended June 30, 2023, compared to a net loss of $84.4 million for the same period in 2022, with an accumulated deficit of $443.7 million as of June 30, 2023[152]. - Net loss for the three months ended June 30, 2023, was $24.6 million, an improvement from a net loss of $34.1 million in the same period of 2022[308]. - Total revenue for the six months ended June 30, 2023, was $7.1 million, attributed to Rett research and development activities[315]. - Revenue for the three months ended June 30, 2023, was $2.4 million, compared to $0 in the same period of 2022[308]. - Research and development expenses for the six months ended June 30, 2023, were $32.3 million, significantly lower than $61.7 million in 2022, a decrease of approximately 47.5%[316]. - General and administrative expenses for the six months ended June 30, 2023, were $14.7 million, down from $21.3 million in 2022, a reduction of about 30.9%[317]. - Research and development expenses decreased to $19.8 million for the three months ended June 30, 2023, down from $23.5 million in 2022, a reduction of approximately 15.7%[310]. - General and administrative expenses were $6.0 million for the three months ended June 30, 2023, compared to $9.9 million in 2022, reflecting a decrease of about 39.4%[311]. - The company has incurred operating losses since inception and expects to continue incurring significant losses for the foreseeable future[296]. Funding and Capital Management - The company has raised an aggregate of $439.0 million in gross proceeds from its initial public offering and follow-on offerings, primarily funding operations through equity sales and a Term Loan Agreement[150]. - As of June 30, 2023, the company had cash and cash equivalents of $45.1 million, funded primarily through equity financings totaling $439.0 million[319]. - The company believes existing cash and cash equivalents, along with anticipated net proceeds from the August 2023 Private Placement, will fund operations into Q3 2025, but additional capital will be required for R&D, manufacturing, and working capital[331]. - The August 2023 Private Placement is expected to generate approximately $150 million in gross proceeds[328]. - The company anticipates further reductions in spending in 2023 compared to 2022 levels due to strategic pipeline prioritization initiatives[329]. - The company is required to regain compliance with the minimum Market Value of Listed Securities of $50,000,000 by January 30, 2024, or face potential delisting[298]. - The company received a Nasdaq notice on April 25, 2023, indicating that the closing bid price for its common stock was below $1.00 for 30 consecutive business days[297]. Research and Development Activities - TSHA-120, a gene therapy for giant axonal neuropathy, has shown clinically meaningful slowing of disease progression in a Phase 1/2 clinical trial, with a pivotal lot release completed in Q4 2022[147]. - TSHA-102, targeting Rett syndrome, has been dosed in adult patients in a Phase 1/2 clinical trial, with no serious adverse events reported as of the six-week assessment[149]. - The company has paused substantially all other R&D activities to increase operational efficiency, focusing on GAN and Rett syndrome[146]. - The company is focused on advancing clinical development for its product candidates while scaling up clinical and regulatory capabilities[153]. - The company is evaluating alternative study designs for TSHA-120 due to the ultra-rare nature of GAN, with regulatory flexibility acknowledged by the FDA[148]. - The company plans to continue reporting quarterly updates on available clinical data from ongoing studies[149]. - The REVEAL Phase 1/2 clinical trial is evaluating TSHA-102 in up to 18 adult female patients with Rett syndrome, with the first patient dosed in the first half of 2023[178]. - The ongoing Phase 1/2 clinical trial of TSHA-120 has intrathecally dosed 14 patients, with 12 patients having up to three years of long-term follow-up data[217]. - The company has deprioritized the evaluation of preclinical product candidates TSHA-105, TSHA-118, and TSHA-121, but may reconsider them in the future as part of pipeline expansion plans[251]. Clinical Trial Results - The FDA acknowledged MFM32 as an acceptable endpoint for TSHA-120 and recommended additional patient dosing in a double-blind, placebo-controlled design[148]. - TSHA-102 demonstrated significant survival improvement in neonatal KO Rett mice, with 47% surviving to 36 weeks compared to a maximum of 13.3 weeks for vehicle-treated controls[170]. - A one-time intrathecal injection of TSHA-102 significantly increased survival across all dose levels in the MECP2 KO mouse model, with improved body weight, motor function, and respiratory assessments[166]. - In a pharmacology study, TSHA-102 at a dose of 8.8x10^10 vg/mouse resulted in near normalization of survival and significant behavioral improvements as measured by the Bird Score[170]. - TSHA-102 showed a well-tolerated safety profile with no treatment-emergent serious adverse events reported as of six weeks post-treatment[180]. - Significant clinical improvement was observed in autonomic function, vocalization, and motor skills, including the ability to sit unassisted for three minutes for the first time in over a decade[183]. - In the REVEAL trial, the first patient dosed showed improvement in key efficacy endpoints four weeks post-TSHA-102 administration[185]. - The RSBQ Total Score showed significant clinical improvement four weeks post-TSHA-102 administration[186]. - No quantifiable seizure events were reported post-TSHA-102 administration through day 35[191]. - At one year post-gene transfer, a statistically significant slowing of disease progression was observed with TSHA-120 at the highest dose, with a 5-point improvement in the MFM32 score compared to an 8-point decline in natural history[218]. - The change in the rate of decline in the MFM32 score for all therapeutic doses combined showed a 5.20% point reduction compared to the pre-gene transfer rate of decline[221]. - There was a 99.9% probability of any slowing of disease progression and a 79.4% probability of clinically meaningful slowing of 50% or more following treatment with TSHA-120 compared to natural history data[223]. - TSHA-120 treatment showed a 7% treatment effect size in MFM32 with an 81% probability of slowing disease progression[231]. - The estimated treatment effect sizes for mFARS and FARS were 31% and 29% respectively, with a 99% probability of slowing deterioration in ataxic motor function[232]. - The DPM indicated a 100% probability of measurable improvement in nerve response with ulnar SNAP and median SNAP amplitude, with estimated treatment effects of 189% and 152% respectively[239]. - TSHA-120 demonstrated a favorable deviation in disease progression across multiple clinical performance and biological endpoints compared to the DPM[229]. - Safety data indicated no significant acute or subacute inflammation or dose-limiting toxicity associated with TSHA-120 treatment[245]. - The pivotal lot of TSHA-120, released in November 2022, yielded over 50 patient doses at the highest dose cohort of 1.0x10^14 vg by ddPCR[249]. Regulatory Designations - The company received orphan drug designation and rare pediatric disease designation from the FDA for TSHA-102 for the treatment of Rett syndrome[181]. - TSHA-120 for Giant Axonal Neuropathy (GAN) has received orphan drug designation and rare pediatric disease designation from the FDA[199]. - The company has received orphan drug designation for both TSHA-105 and TSHA-118 from the FDA, indicating the potential for significant market opportunities[260][257]. - TSHA-118 has received orphan drug designation and fast track designation from the FDA, with clinical trial material ready for use[257]. Operational Challenges - The company faces numerous risks and uncertainties in estimating future operating capital requirements, which depend on various factors including clinical trial progress and regulatory reviews[332]. - The company has not recognized any revenue from product sales to date and does not expect to generate revenue from product sales in the foreseeable future[300]. - A non-cash impairment charge was recorded in November 2022 related to the decision not to continue building a manufacturing facility in North Carolina[306]. - The company has no off-balance sheet arrangements during the periods presented[339]. - The company has elected to delay the adoption of certain accounting standards under the JOBS Act, allowing it to comply with new or revised accounting standards at a later date[342].

Taysha Gene Therapies, Inc. (NASDAQ:TSHA) Q1 2023 Earnings Conference Call May 11, 2023 4:30 PM ET Company Participants Hayleigh Collins - Director and Head of Corporate Communications Sean Nolan - CEO Sukumar Nagendran - President and Head of Research and Development Salman Bhai - Assistant Professor of Neurology at UT Kamran Alam - CFO Conference Call Participants Abigail Gray - Baird Gil Blum - Needham & Co. Operator Thank you for standing by. This is the conference operator. Welcome to the Taysha Gene T ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________ to ___________ Commission File Number: 001-39536 Taysha Gene Therapies, Inc. (Exact Name of Registrant as Specified in its Charter) ( State or other jurisdiction of inco ...

Taysha Gene Therapies, Inc. (NASDAQ:TSHA) Q4 2022 Earnings Conference Call March 28, 2023 4:30 PM ET Company Participants Hayleigh Collins - Director and Head of Corporate Communications Sean Nolan - Chief Executive Officer Sukumar Nagendran - President and Head of Research and Development Kamran Alam - Chief Financial Officer Conference Call Participants Whitney Ijem - Canaccord Genuity Jack Allen - Robert W. Baird & Co. Silvan Tuerkcan - JMP Securities Yun Zhong - BTIG David Hoang - SMBC Nikko Securities ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________ to ___________ WASHINGTON, DC 20549 FORM 10-K Commission File Number: 001-39536 Taysha Gene Therapies, Inc. (Exact Name of Registrant as Specified in its Charter) | Delaware | 84-31995 ...

Taysha Gene Therapies, Inc. (NASDAQ:TSHA) Q3 2022 Results Earnings Conference Call November 8, 2022 8:00 AM ET Company Participants Kimberly Lee - Chief Corporate Affairs Officer RA Session - President, Founder and Chief Executive Officer Suyash Prasad - Chief Medical Officer and Head of Research and Development Kamran Alam - Chief Financial Officer Fred Porter - Chief Technical Officer Conference Call Participants Gil Blum - Needham & Company, LLC Geulah Livshits - Chardan Mehdi Goudarzi - Truist Securitie ...