Organization and Description of Business Operations	12 Months Ended
Dec. 31, 2022
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 (“Inception”). 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 patient-centric gene therapy company focused on developing and commercializing AAV-based gene therapies for the treatment of monogenic diseases of the central nervous system in both rare and large patient populations. 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, 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 December 31, 2022. Liquidity and Going Concern In October 2022, the Company entered into a securities purchase agreement (the “Securities Purchase Agreement”) and an option agreement (the “Option Agreement,” together with the Securities Purchase Agreement, the “Astellas Transactions”) with Audentes Therapeutics, Inc. (d/b/a Astellas Gene Therapy) (“Astellas”), pursuant to which the Company agreed to issue and sell 7,266,342 shares of its common stock for aggregate proceeds of $30.0 million and received a one-time payment in the amount of $20.0 million (the “Upfront Payment”), respectively, for total gross proceeds of $50.0 million. See Note 6 for additional information. Also in October 2022, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with Goldman Sachs & Co. LLC (the "Underwriter”) to issue and sell 14,000,000 shares of common stock at a price to the public of $2.00 per share. The Underwriter exercised its option to purchase an additional 765,226 shares of the Company’s common stock at a price of $1.88 per share. The net proceeds from the offering were $27.7 million, after deducting underwriting discounts and other offering expenses. The accompanying consolidated financial statements are prepared in accordance with generally accepted accounting principles applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. 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. As of December 31, 2022, the Company had an accumulated deficit of $401.4 million and cash and cash equivalents of $87.9 million. Losses are expected to continue as the Company continues to invest in its research and development activities. Management believes that there is presently insufficient funding available to allow the Company to fund its currently planned research and discovery programs for a period exceeding one year from the date of this filing with the Securities and Exchange Commission ("SEC"). These conditions and events raise substantial doubt about the Company’s ability to continue as a going concern. In response to these conditions and to meet the Company’s capital requirements, management plans to use its current cash on hand and some combination of the following: (i) dilutive and/or non-dilutive financings, (ii) out-licensing or strategic alliances/collaborations, and (iii) out-licensing or sale of its non-core assets. If the Company raises additional funds through collaborations, strategic alliances, business development or licensing arrangements with third parties, the Company might have to relinquish valuable rights to its technologies, future revenue streams, research programs or product candidates. However, these plans have not yet been finalized and are not within the Company’s control, and therefore cannot be deemed probable. As a result, the Company has concluded that management’s plans do not alleviate substantial doubt about the Company’s ability to continue as a going concern. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

Organization and Description of Business Operations

12 Months Ended

Dec. 31, 2022

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 (“Inception”). 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 patient-centric gene therapy company focused on developing and commercializing AAV-based gene therapies for the treatment of monogenic diseases of the central nervous system in both rare and large patient populations.

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, 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 December 31, 2022.

Liquidity and Going Concern

In October 2022, the Company entered into a securities purchase agreement (the “Securities Purchase Agreement”) and an option agreement (the “Option Agreement,” together with the Securities Purchase Agreement, the “Astellas Transactions”) with Audentes Therapeutics, Inc. (d/b/a Astellas Gene Therapy) (“Astellas”), pursuant to which the Company agreed to issue and sell 7,266,342 shares of its common stock for aggregate proceeds of $30.0 million and received a one-time payment in the amount of $20.0 million (the “Upfront Payment”), respectively, for total gross proceeds of $50.0 million. See Note 6 for additional information.

Also in October 2022, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with Goldman Sachs & Co. LLC (the "Underwriter”) to issue and sell 14,000,000 shares of common stock at a price to the public of $2.00 per share. The Underwriter exercised its option to purchase an additional 765,226 shares of the Company’s common stock at a price of $1.88 per share. The net proceeds from the offering were $27.7 million, after deducting underwriting discounts and other offering expenses.

The accompanying consolidated financial statements are prepared in accordance with generally accepted accounting principles applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business.

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. As of December 31, 2022, the Company had an accumulated deficit of $401.4 million and cash and cash equivalents of $87.9 million. Losses are expected to continue as the Company continues to invest in its research and development activities. Management believes that there is presently insufficient funding available to allow the Company to fund its currently planned research and discovery programs for a period exceeding one year from the date of this filing with the Securities and Exchange Commission ("SEC"). These conditions and events raise substantial doubt about the Company’s ability to continue as a going concern.

In response to these conditions and to meet the Company’s capital requirements, management plans to use its current cash on hand and some combination of the following: (i) dilutive and/or non-dilutive financings, (ii) out-licensing or strategic alliances/collaborations, and (iii) out-licensing or sale of its non-core assets. If the Company raises additional funds through collaborations, strategic alliances, business development or licensing arrangements with third parties, the Company might have to relinquish valuable rights to its technologies, future revenue streams, research programs or product candidates. However, these plans have not yet been finalized and are not within the Company’s control, and therefore cannot be deemed probable. As a result, the Company has concluded that management’s plans do not alleviate substantial doubt about the Company’s ability to continue as a going concern.

The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.