Organization and Description of Business Operations	6 Months Ended
Jun. 30, 2025
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business Operations	Note 1—Organization and Description of Business Operations Taysha Gene Therapies, Inc. (the “Company” or “Taysha”) was originally formed under the laws of the State of Texas on September 20, 2019. Taysha converted to a Delaware corporation on February 13, 2020, which had no impact to the Company’s par value or issued and authorized capital structure. Taysha is a clinical-stage biotechnology company focused on advancing AAV-based gene therapies for severe monogenic diseases of the central nervous system. Sales Agreement On October 5, 2021, the Company entered into a Sales Agreement (the “Sales Agreement”) with SVB Securities LLC (f/k/a SVB Leerink LLC) and Wells Fargo Securities, LLC (collectively, the “Sales Agents”), pursuant to which the Company may issue and sell, from time to time in its sole discretion, shares of its common stock having an aggregate offering price of up to $150.0 million through the Sales Agents. In March 2022, the Company amended the Sales Agreement to, among other things, include Goldman Sachs & Co. LLC as an additional Sales Agent. The Sales Agents may sell common stock by any method permitted by law deemed to be an “at-the-market offering” as defined in Rule 415(a)(4) of the Securities Act (the “ATM”), including sales made directly on or through the Nasdaq Global Select Market or any other existing trade market for the common stock, in negotiated transactions at market prices prevailing at the time of sale or at prices related to prevailing market prices, or any other method permitted by law. The Sales Agents are entitled to receive 3.0% of the gross sales price per share of common stock sold under the Sales Agreement. In April 2022, the Company sold 2,000,000 shares of common stock under the Sales Agreement and received $11.6 million in net proceeds. No other shares of common stock have been issued and sold pursuant to the Sales Agreement as of June 30, 2025. On December 13, 2024, the Company filed a new shelf registration statement on Form S-3 following the expiration of its prior registration statement, in relation to the registration of common stock, preferred stock, debt securities, warrants and units or any combination thereof up to a total aggregate offering price of $300.0 million, including up to $100.0 million shares of common stock that may be offered and sold pursuant to the Sales Agreement. On May 28, 2025, the Company notified the Sales Agents that it was suspending and terminating the prospectus (the “ATM Prospectus”) related to up to $100.0 million of the Company’s common stock issuable pursuant to the Sales Agreement. The Company will not make any sales of its securities pursuant to the Sales Agreement unless and until a new prospectus, prospectus supplement or a new registration statement is filed. Other than the termination of the ATM Prospectus, the Sales Agreement remains in full force and effect. Liquidity and Capital Resources The Company has incurred operating losses since inception and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. Losses are expected to continue as the Company continues to invest in its research and development activities. As of June 30, 2025, the Company had an accumulated deficit of $650.7 million. The Company expects to continue to incur significant expenses and operating losses for the foreseeable future. On May 28, 2025, the Company entered into an underwriting agreement (the “May 2025 Underwriting Agreement”) with Jefferies LLC, BofA Securities, Inc., Piper Sandler & Co. and Barclays Capital Inc, as representatives of the several underwriters set forth therein (collectively, the “Underwriters”), to issue and sell 46,868,687 shares of the Company’s common stock and, in lieu of common stock to certain investors, pre-funded warrants to purchase 25,858,586 shares of its common stock in an underwritten public offering (the “May 2025 Offering”), pursuant to an effective shelf registration statement on Form S-3 and a related prospectus and prospectus supplement. The offering price to the public was $2.75 per share of common stock and $2.749 per pre-funded warrant, which was the price to the public of each share of common stock sold in the May 2025 Offering minus the $0.001 exercise price per pre-funded warrant. The Underwriters purchased the shares and the pre-funded warrants from the Company pursuant to the May 2025 Underwriting Agreement at a price of $2.585 per share and $2.584 per pre-funded warrant, respectively. See Note 10 for additional information. The initial closing of the May 2025 Offering occurred on May 30, 2025. In addition, the Company granted the Underwriters an option to purchase, for a period of 30 days, up to an additional 10,909,090 shares of common stock, which the Underwriters exercised in full on June 6, 2025. The total net proceeds from the May 2025 Offering were approximately $215.6 million, including the proceeds from the Underwriter’s option, after deducting underwriting discounts and commissions and offering expenses. Future capital requirements will depend on many factors, including the timing and extent of spending on research and development and the market acceptance of the Company’s products. The Company will need to obtain additional financing in order to complete clinical studies and launch and commercialize any product candidates for which it receives regulatory approval. There can be no assurance that such financing will be available or will be on terms acceptable to the Company. As of June 30, 2025, the Company had cash and cash equivalents of $312.8 million, which the Company believes will be sufficient to fund its planned operations for a period of at least twelve months from the date of issuance of these unaudited condensed consolidated financial statements. The Company has based this estimate on assumptions that may prove to be wrong, and its operating plan may change as a result of many factors currently unknown to it. As a result, the Company could deplete its capital resources sooner than it currently expects. The Company expects to finance its future cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements. If the Company is unable to obtain funding, the Company would be forced to delay, reduce or eliminate some or all of its research and development programs, preclinical and clinical testing or commercialization efforts, which could adversely affect its business prospects.

Organization and Description of Business Operations

6 Months Ended

Jun. 30, 2025

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization and Description of Business Operations

Note 1—Organization and Description of Business Operations

Taysha Gene Therapies, Inc. (the “Company” or “Taysha”) was originally formed under the laws of the State of Texas on September 20, 2019. Taysha converted to a Delaware corporation on February 13, 2020, which had no impact to the Company’s par value or issued and authorized capital structure.

Taysha is a clinical-stage biotechnology company focused on advancing AAV-based gene therapies for severe monogenic diseases of the central nervous system.

Sales Agreement

On October 5, 2021, the Company entered into a Sales Agreement (the “Sales Agreement”) with SVB Securities LLC (f/k/a SVB Leerink LLC) and Wells Fargo Securities, LLC (collectively, the “Sales Agents”), pursuant to which the Company may issue and sell, from time to time in its sole discretion, shares of its common stock having an aggregate offering price of up to $150.0 million through the Sales Agents. In March 2022, the Company amended the Sales Agreement to, among other things, include Goldman Sachs & Co. LLC as an additional Sales Agent. The Sales Agents may sell common stock by any method permitted by law deemed to be an “at-the-market offering” as defined in Rule 415(a)(4) of the Securities Act (the “ATM”), including sales made directly on or through the Nasdaq Global Select Market or any other existing trade market for the common stock, in negotiated transactions at market prices prevailing at the time of sale or at prices related to prevailing market prices, or any other method permitted by law. The Sales Agents are entitled to receive 3.0% of the gross sales price per share of common stock sold under the Sales Agreement. In April 2022, the Company sold 2,000,000 shares of common stock under the Sales Agreement and received $11.6 million in net proceeds. No other shares of common stock have been issued and sold pursuant to the Sales Agreement as of June 30, 2025.

On December 13, 2024, the Company filed a new shelf registration statement on Form S-3 following the expiration of its prior registration statement, in relation to the registration of common stock, preferred stock, debt securities, warrants and units or any combination thereof up to a total aggregate offering price of $300.0 million, including up to $100.0 million shares of common stock that may be offered and sold pursuant to the Sales Agreement.

On May 28, 2025, the Company notified the Sales Agents that it was suspending and terminating the prospectus (the “ATM Prospectus”) related to up to $100.0 million of the Company’s common stock issuable pursuant to the Sales Agreement. The Company will not make any sales of its securities pursuant to the Sales Agreement unless and until a new prospectus, prospectus supplement or a new registration statement is filed. Other than the termination of the ATM Prospectus, the Sales Agreement remains in full force and effect.

Liquidity and Capital Resources

The Company has incurred operating losses since inception and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. Losses are expected to continue as the Company continues to invest in its research and development activities. As of June 30, 2025, the Company had an accumulated deficit of $650.7 million. The Company expects to continue to incur significant expenses and operating losses for the foreseeable future.

On May 28, 2025, the Company entered into an underwriting agreement (the “May 2025 Underwriting Agreement”) with Jefferies LLC, BofA Securities, Inc., Piper Sandler & Co. and Barclays Capital Inc, as representatives of the several underwriters set forth therein (collectively, the “Underwriters”), to issue and sell 46,868,687 shares of the Company’s common stock and, in lieu of common stock to certain investors, pre-funded warrants to purchase 25,858,586 shares of its common stock in an underwritten public offering (the “May 2025 Offering”), pursuant to an effective shelf registration statement on Form S-3 and a related prospectus and prospectus supplement. The offering price to the public was $2.75 per share of common stock and $2.749 per pre-funded warrant, which was the price to the public of each share of common stock sold in the May 2025 Offering minus the $0.001 exercise price per pre-funded warrant. The Underwriters purchased the shares and the pre-funded warrants from the Company pursuant to the May 2025 Underwriting Agreement at a price of $2.585 per share and $2.584 per pre-funded warrant, respectively. See Note 10 for additional information. The initial closing of the May 2025 Offering occurred on May 30, 2025. In addition, the Company granted the Underwriters an option to purchase, for a period of 30 days, up to an additional 10,909,090 shares of common stock, which the Underwriters exercised in full on June 6, 2025. The total net proceeds from the May 2025 Offering were approximately $215.6 million, including the proceeds from the Underwriter’s option, after deducting underwriting discounts and commissions and offering expenses.

Future capital requirements will depend on many factors, including the timing and extent of spending on research and development and the market acceptance of the Company’s products. The Company will need to obtain additional financing in order to complete clinical studies and launch and commercialize any product candidates for which it receives regulatory approval. There can be no assurance that such financing will be available or will be on terms acceptable to the Company. As of June 30, 2025, the Company had cash and cash equivalents of $312.8 million, which the Company believes will be sufficient to fund its planned operations for a period of at least twelve months from the date of issuance of these unaudited condensed consolidated financial statements. The Company has based this estimate on assumptions that may prove to be wrong, and its operating plan may change as a result of many factors currently unknown to it. As a result, the Company could deplete its capital resources sooner than it currently expects. The Company expects to finance its future cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements. If the Company is unable to obtain funding, the Company would be forced to delay, reduce or eliminate some or all of its research and development programs, preclinical and clinical testing or commercialization efforts, which could adversely affect its business prospects.