Taysha Gene Therapies, Inc.

Previous wording

The REVEAL Phase 1/2 Adolescent and Adult Trial, also known as Part A, is a first-in-human, open-label, randomized, dose-escalation and dose-expansion study evaluating the safety and preliminary efficacy of TSHA-102 as a single lumbar intrathecal administration in adolescent and adult females aged 12 years and older with Rett syndrome due to MECP2 loss-of-function mutation. The trial is taking place in Canada and the United States. A total of six participants aged 15 to 21 years were treated with TSHA-102 in this study, and enrollment for this trial is complete. Part A also includes the REVEAL Phase 1/2 Pediatric Trial, which is a first-in-human, open-label, randomized, dose-escalation and dose-expansion study evaluating the safety and preliminary efficacy of TSHA-102 as a single lumbar intrathecal administration in pediatric females aged 5 to 8 years with Rett syndrome due to MECP2 loss-of-function mutation. The trial is taking place in the United States and Canada. A total of six participants aged 6 to 8 years were treated with TSHA-102 in this study, and enrollment for this trial is also complete.

Current wording

The REVEAL Phase 1/2 Adolescent and Adult Trial, also known as Part A, is a first-in-human, open-label, randomized, dose-escalation and dose-expansion study evaluating the safety and preliminary efficacy of TSHA-102 as a single lumbar intrathecal administration in adolescent and adult females aged 12 years and older with Rett syndrome due to MECP2 loss-of-function mutation. The trial is taking place in Canada and the United States. A total of six patients aged 15 to 21 years were treated with TSHA-102 in this study, and enrollment for this trial is complete. Part A also includes the REVEAL Phase 1/2 Pediatric Trial, which is a first-in-human, open-label, randomized, dose-escalation and dose-expansion study evaluating the safety and preliminary efficacy of TSHA-102 as a single lumbar intrathecal administration in pediatric females aged 5 to 8 years with Rett syndrome due to MECP2 loss-of-function mutation. The trial is taking place in the United States and Canada. A total of six patients aged 6 to 8 years were treated with TSHA-102 in this study, and enrollment for this trial is also complete.

Previous wording

We have completed dosing of the 12 patients in Part A of both REVEAL trials, which includes eight patients in cohort two (high dose, 1x1015 total vg) and four patients in cohort one (low dose, 5.7x1014 total vg). We reported positive clinical data in May 2025, demonstrating that the first 10 patients gained or regained one or more developmental milestone across communication, fine motor and gross motor function following TSHA-102 as of the May 19, 2025 data cutoff. Patients also showed improvements across multiple standardized Rett syndrome assessments. High dose (1x1015 total vg) and low dose (5.7x1014 total vg) TSHA-102 continue to be generally well tolerated with no treatment-related serious adverse events, or SAEs, or dose-limiting toxicities, or DLTs, in all patients treated in the REVEAL Phase 1/2 and REVEAL pivotal trials as of the May 2026 data cutoff.

Current wording

We have completed dosing of the 12 patients aged 6 to 21 years in Part A of both REVEAL trials, which includes eight patients in cohort two (high dose, 1x1015 total vg) and four patients in cohort one (low dose, 5.7x1014 total vg).

Previous wording

The TSHA-102 clinical development program is designed to support the potential future approval of TSHA-102 for a broad population of patients aged 2 years and older with Rett syndrome through an efficient and rigorously designed pathway. In close collaboration with the United States Food and Drug Administration, or FDA, we designed the TSHA-102 pivotal program so that efficacy data from the REVEAL pivotal trial in participants aged 6 to <22 years who have reached developmental plateau can be used to represent patients aged 2 to <6 years, while safety data in younger children are generated through the separate ASPIRE trial to support the potential for a broad label for TSHA-102.

Current wording

The TSHA-102 clinical development program is designed to support the potential future approval of TSHA-102 for a broad population of patients aged 2 years and older with Rett syndrome through an efficient and rigorously designed pathway. In close collaboration with the United States Food and Drug Administration, or FDA, we designed the TSHA-102 pivotal program so that efficacy data from the REVEAL pivotal trial in patients aged 6 to <22 years who have reached developmental plateau can be used to represent patients aged 2 to <6 years, while safety data in younger children are generated through the separate ASPIRE trial to support the potential for a broad label for TSHA-102.

Previous wording

The REVEAL pivotal trial, also known as Part B, is a single-arm, open-label study evaluating the efficacy and safety of TSHA-102 in females with Rett syndrome, with each patient serving as their own control. Each participant will receive a single administration of the high dose (1x1015 total vg) of TSHA-102 delivered by lumbar intrathecal injection. The study will enroll 15 females aged 6 to <22 years in the developmental plateau population of Rett syndrome; these patients have an exceedingly low likelihood (0% to <6.7%) of gaining new or regaining developmental milestones that were lost after a defined number of years, based on our analysis of the National Institutes of Health, or NIH, -funded International Rett Syndrome Foundation’s natural history study data. The primary endpoint will assess response rate, defined as the percentage of patients who gain or regain at least one developmental milestone from a list of 28 defined milestones across the core functional domains of communication, fine motor and gross motor, following administration of TSHA-102. Standardized milestone assessments will be administered and captured on video at pre- and post-treatment timepoints, with determination of milestone gain/regain upon video-evidence review by independent, blinded central raters based on prespecified definitions of achievement for each milestone.

Current wording

The REVEAL pivotal trial, also known as Part B, is a single-arm, open-label study evaluating the efficacy and safety of high dose TSHA-102 as a single lumbar intrathecal administration in females aged 6 to <22 years with Rett syndrome due to MECP2 loss-of-function mutation, with each patient serving as their own control. The trial is taking place in the United States. The study enrolled females in the developmental plateau population of Rett syndrome; these patients have an exceedingly low likelihood (0% to <6.7%) of gaining new or regaining developmental milestones that were lost after a defined number of years, based on our analysis of the National Institutes of Health, or NIH, -funded International Rett Syndrome Foundation’s natural history study data. The primary endpoint will assess response rate, defined as the percentage of patients who gain or regain at least one developmental milestone from a list of 28 natural-history defined milestones across the core functional domains of communication, fine motor and gross motor, following administration of TSHA-102. The response rate of 33% is the minimum threshold for success sufficient to reject the natural history established null hypothesis of 6.7%.

Previous wording

We also obtained written alignment from the FDA on an extrapolation approach in a separate safety-focused study, which we refer to as the ASPIRE trial, and the data for inclusion in the planned BLA submission to enable potential broad labeling of TSHA-102 for patients aged ≥2 years with Rett syndrome. ASPIRE will enroll three females aged 2 to <4 years with Rett syndrome to evaluate the safety and preliminary efficacy of a single intrathecal administration of high dose TSHA-102 (1x1015 total vg), scaled to account for the lower brain volume in 2 to <4‑year‑olds. A minimum of three months of ASPIRE safety data will be included in the planned BLA submission, while efficacy in the 2 to <6-year-old population will be extrapolated from data collected in the REVEAL pivotal trial, to support the potential for a broad label for TSHA-102 in patients aged ≥2 years with Rett syndrome. We expect to complete dosing in the ASPIRE trial in the second quarter of 2026.

Current wording

We also obtained written alignment from the FDA on an extrapolation approach in a separate safety-focused study, which we refer to as the ASPIRE trial, and the data for inclusion in the planned BLA submission to enable potential broad labeling of TSHA-102 for patients aged ≥2 years with Rett syndrome. We have completed dosing of four patients aged 2 to <4 years with Rett syndrome in the overenrolled ASPIRE trial to evaluate the safety and preliminary efficacy of a single intrathecal administration of high dose TSHA-102 (1x1015 total vg), scaled to account for the lower brain volume in 2 to <4-year-olds. A minimum of three months of ASPIRE safety data will be included in the planned BLA submission, while efficacy in the 2 to <6-year-old population will be extrapolated from data collected in the REVEAL pivotal trial.

Previous wording

We have a limited operating history. Since our inception, our operations have focused on organizing and staffing our company, business planning, raising capital and entering into collaboration agreements for conducting preclinical and clinical development activities for our product candidates. Our lead product candidate is still in the clinical stage. We do not have any product candidates approved for sale and have not generated any revenue from product sales. Through March 31, 2026, we have funded our operations primarily through: (i) the sale of equity, raising an aggregate of $961.0 million of gross proceeds from our initial public offering, or the IPO, sales of common stock pursuant to our Sales Agreement (as defined below), our October 2022 follow-on offering, our 2023 private placement, our June 2024 Offering (as defined below) and our May 2025 Offering (as defined below); (ii) pre-IPO private placements of our convertible preferred stock; (iii) our 2023 Term Loan Agreement (as defined below) and subsequently the 2025 Trinity Term Loan Agreement (as defined below); and (iv) the Astellas Transactions.

Current wording

We have a limited operating history. Since our inception, our operations have focused on organizing and staffing our company, business planning, raising capital and entering into collaboration agreements for conducting preclinical and clinical development activities for our product candidates. Our lead product candidate is still in the clinical stage. We do not have any product candidates approved for sale and have not generated any revenue from product sales. Through June 30, 2026, we have funded our operations primarily through: (i) the sale of equity, raising an aggregate of $1,191.0 million of gross proceeds from our IPO and subsequent public and private offerings of common stock; (ii) pre-IPO private placements of our convertible preferred stock; (iii) our 2023 Trinity Term Loan Agreement (as defined below) and subsequently the 2025 Trinity Term Loan Agreement (as defined below); and (iv) the option agreement dated October 21, 2022, with Audentes Therapeutics, Inc. (d/b/a Astellas Gene Therapy) and the securities purchase agreement dated October 21, 22 with Astellas, or the Astellas Transactions.

Previous wording

Since our inception, we have incurred significant operating losses. Our net losses were $42.4 million for the three months ended March 31, 2026. As of March 31, 2026, we had an accumulated deficit of $753.7 million. We expect to continue to incur significant expenses and operating losses for the foreseeable future. We anticipate that our expenses will increase significantly in connection with our ongoing activities, as we:

Current wording

Since our inception, we have incurred significant operating losses. Our net losses were $89.0 million for the six months ended June 30, 2026. As of June 30, 2026, we had an accumulated deficit of $800.3 million. We expect to continue to incur significant expenses and operating losses for the foreseeable future. We anticipate that our expenses will increase significantly in connection with our ongoing activities, as we:

Previous wording

In March 2022, our clinical trial application filing for TSHA-102 for the treatment of Rett Syndrome was approved by Health Canada and therefore triggered a regulatory milestone payment in connection with the Abeona Rett Agreement. We recorded a $1.0 million charge within research and development expenses in the consolidated statements of operations for the year ended December 31, 2022. In May 2023, we dosed the first patient with TSHA-102 in the Phase 1/2 REVEAL trial evaluating the safety and preliminary efficacy of TSHA-102 in adult patients with Rett syndrome and therefore triggered a milestone payment of $3.5 million in connection with the Abeona Rett Agreement. In December 2025, we dosed the first patient with TSHA-102 in the Phase 1/2 Part B REVEAL pivotal trial and therefore triggered a milestone payment of $3 million in connection with this agreement. This pivotal milestone fee was paid in January 2026. We recorded $3.0 million as an investing cash outflow in our condensed consolidated statement of cash flows for the three months ended March 31, 2026. No other milestone payments were made or triggered in connection with this agreement during the three months ended March 31, 2026.

Current wording

In March 2022, our clinical trial application filing for TSHA-102 for the treatment of Rett Syndrome was approved by Health Canada and therefore triggered a regulatory milestone payment in connection with the Abeona Rett Agreement. We recorded a $1.0 million charge within research and development expenses in the consolidated statements of operations for the year ended December 31, 2022. In May 2023, we dosed the first patient with TSHA-102 in the Phase 1/2 REVEAL trial evaluating the safety and preliminary efficacy of TSHA-102 in adult patients with Rett syndrome and therefore triggered a milestone payment of $3.5 million in connection with the Abeona Rett Agreement. In December 2025, we dosed the first patient with TSHA-102 in the Phase 1/2 Part B REVEAL pivotal trial and therefore triggered a milestone payment of $3 million in connection with this agreement. This pivotal milestone fee was paid in January 2026. We recorded $3.0 million as an investing cash outflow in our condensed consolidated statement of cash flows for the six months ended June 30, 2026. No other milestone payments were made or triggered in connection with this agreement during the six months ended June 30, 2026.

Previous wording

Revenue for the three months ended March 31, 2025 was derived from the Astellas Transactions. We recognized revenue as research and development activities related to our Rett program were performed. Revenue related to the material rights associated with the Rett Option and the GAN Option were recognized at a point in time when the option was exercised or the option period expired. In September 2023, Astellas elected not to exercise the GAN Option, therefore we recognized revenue related to the GAN Option during the year ended December 31, 2023. In October 2025, Astellas elected not to exercise the Rett Option, therefore we recognized revenue related to the Rett Option during the year ended December 31, 2025. All revenue related to the Astellas Transactions was recognized as of December 31, 2025.

Current wording

Revenue for the six months ended June 30, 2025 was derived from the Astellas Transactions. We recognized revenue as research and development activities related to our Rett program were performed. Revenue related to the material rights associated with the Rett Option and the GAN Option were recognized at a point in time when the option was exercised or the option period expired. In September 2023, Astellas elected not to exercise the GAN Option, therefore we recognized revenue related to the GAN Option during the year ended December 31, 2023. In October 2025, Astellas elected not to exercise the Rett Option, therefore we recognized revenue related to the Rett Option during the year ended December 31, 2025. All revenue related to the Astellas Transactions was recognized as of December 31, 2025.

Previous wording

Revenue was zero for the three months ended March 31, 2026, compared to $2.3 million for the three months ended March 31, 2025. The revenue recorded for the three months ended March 31, 2025, was derived entirely from the Astellas Transactions as a result of Rett research and development activities performed during the period.

Current wording

Revenue was zero for the three months ended June 30, 2026, compared to $2.0 million for the three months ended June 30, 2025. The revenue recorded for the three months ended June 30, 2025, was derived entirely from the Astellas Transactions as a result of Rett research and development activities performed during the period.

Previous wording

Research and development expenses were $33.8 million for the three months ended March 31, 2026, compared to $15.6 million for the three months ended March 31, 2025. The $18.2 million increase was primarily driven by BLA-enabling PPQ manufacturing initiatives performed during the three months ended March 31, 2026 and higher clinical expenses from the REVEAL Part A Phase 1/2, REVEAL Part B pivotal, and ASPIRE trials. Compensation expenses, including non-cash stock-based compensation, also increased as a result of additional research and development headcount.

Current wording

Research and development expenses were $38.6 million for the three months ended June 30, 2026, compared to $20.1 million for the three months ended June 30, 2025. The $18.5 million increase was primarily driven by BLA-enabling PPQ manufacturing initiatives performed during the three months ended June 30, 2026 and higher clinical expenses from the REVEAL Part A Phase 1/2, REVEAL Part B pivotal, and ASPIRE trials. Compensation expenses, including non-cash stock-based compensation, also increased as a result of additional research and development headcount.

Previous wording

General and administrative expenses were $9.7 million for the three months ended March 31, 2026, compared to $8.2 million for the three months ended March 31, 2025. The increase of $1.5 million was primarily due to higher compensation expenses, including non-cash stock-based compensation expense, and increases in consulting and professional fees, including commercial launch-readiness initiatives.

Current wording

General and administrative expenses were $12.1 million for the three months ended June 30, 2026, compared to $8.6 million for the three months ended June 30, 2025. The increase of $3.5 million was primarily due to higher compensation expenses, including non-cash stock-based compensation expense, and increases in consulting and professional fees, including commercial launch-readiness initiatives.

Previous wording

Change in fair value of warrant liability was a non-cash gain totaling $0.1 million for the three months ended March 31, 2025 related to the SSI Warrants. In December 2025, all vested and outstanding liability classified warrants were exercised, therefore the change in fair value of warrant liability was zero for the three months ended March 31, 2026.

Current wording

Change in fair value of warrant liability was a non-cash loss totaling $0.3 million for the three months ended June 30, 2025 related to the SSI Warrants. In December 2025, all vested and outstanding liability classified warrants were exercised, therefore the change in fair value of warrant liability was zero for the three months ended June 30, 2026.

Previous wording

Interest income was $2.6 million for the three months ended March 31, 2026 compared to $1.3 million for the three months ended March 31, 2025. The increase in income was attributable to higher dividends earned from our money market fund.

Current wording

Interest income was $2.3 million for the three months ended June 30, 2026 compared to $1.9 million for the three months ended June 30, 2025. The increase in income was attributable to higher dividends earned from our money market fund.

Previous wording

Since our inception, we have not generated any revenue from product sales and have incurred significant operating losses. As of March 31, 2026, we had cash and cash equivalents of $276.6 million. We have funded our operations primarily through equity financings, raising an aggregate of $961.0 million in gross proceeds from equity financings, including from pre-IPO private placements of convertible preferred stock, our IPO, and subsequent sales of common stock in public and private securities offerings, proceeds from a warrant exercise, our term loans and the Astellas Transactions.

Current wording

Since our inception, we have not generated any revenue from product sales and have incurred significant operating losses. As of June 30, 2026, we had cash and cash equivalents of $455.4 million. We have funded our operations primarily through equity financings, raising an aggregate of $1.19 billion in gross proceeds from equity financings, including from pre-IPO private placements of convertible preferred stock, our IPO, and subsequent sales of common stock in public and private securities offerings, proceeds from a warrant exercise, our term loans and the Astellas Transactions.

Previous wording

On August 7, 2025, or the Trinity Refinance Date, we entered into a Loan and Security Agreement, or the 2025 Trinity Term Loan Agreement, by and among us, the lenders party thereto from time to time, or the 2025 Trinity Lenders, and Trinity Capital Inc., as administrative agent and collateral agent for the 2025 Trinity Lenders, or Trinity. The 2025 Trinity Term Loan Agreement provides for (i) on the Trinity Refinance Date, $50.0 million aggregate principal amount of term loans, or Tranche A (ii) from the Trinity Refinance Date until March 31, 2028 an additional $25.0 million term loan facility contingent on delivering evidence satisfactory to Trinity that we have submitted a BLA acceptance to the FDA for TSHA-102 in Rett Syndrome, or Tranche B, (iii) from the Trinity Refinance Date until March 31, 2029, an additional $25.0 million term loan facility contingent on delivering evidence satisfactory to Trinity that we have received BLA approval from the FDA for TSHA-102 in Rett Syndrome, or collectively, the 2025 Trinity Term Loans, and, together with the 2023 Trinity Term Loans, the Trinity Term Loans. We drew $50.0 million in term loans on the Trinity Refinance Date. The existing 2023 Trinity Term Loan Agreement was terminated and the existing 2023 Trinity Term Loans were repaid concurrently with entry into the 2025 Trinity Term Loan Agreement and the draw of Tranche A. The interest rate applicable to the 2025 Trinity Term Loans is the greater of (a) the WSJ Prime Rate plus 4.00% or (b) 11.50% per annum. The 2025 Trinity Term Loans are interest only from the Trinity Refinance Date through 48 months from the Trinity Refinance Date, which may be extended to 60 months from the Trinity Refinance Date upon the satisfaction of certain milestones set forth in the 2025 Trinity Term Loan Agreement, after which we are required to pay equal monthly installments of principal through August 1, 2030, or the New Maturity Date.

Current wording

On August 7, 2025, or the Trinity Refinance Date, we entered into a Loan and Security Agreement, or the 2025 Trinity Term Loan Agreement, by and among us, the lenders party thereto from time to time, or the 2025 Trinity Lenders, and Trinity Capital Inc., as administrative agent and collateral agent for the 2025 Trinity Lenders, or Trinity. The 2025 Trinity Term Loan Agreement provides for (i) on the Trinity Refinance Date, $50.0 million aggregate principal amount of term loans, or Tranche A (ii) from the Trinity Refinance Date until March 31, 2028 an additional $25.0 million term loan facility contingent on delivering evidence satisfactory to Trinity that we have submitted a BLA acceptance to the FDA for TSHA-102 in Rett Syndrome, or Tranche B, (iii) from the Trinity Refinance Date until March 31, 2029, an additional $25.0 million term loan facility contingent on delivering evidence satisfactory to Trinity that we have received BLA approval from the FDA for TSHA-102 in Rett Syndrome, or collectively, the 2025 Trinity Term Loans, and, together with the 2023 Trinity Term Loans, the Trinity Term Loans. We drew $50.0 million in term loans on the Trinity Refinance Date. The existing 2023 Trinity Term Loan Agreement was terminated and the existing 2023 Trinity Term Loans were repaid concurrently with entry into the 2025 Trinity Term Loan Agreement and the draw of Tranche A. The interest rate applicable to the 2025 Trinity Term Loans is the greater of (a) the WSJ Prime Rate plus 4.00% or (b) 11.50% per annum. The 2025 Trinity Term Loans are interest only from the Trinity Refinance Date through 48 months from the Trinity Refinance Date, which may be extended to 60 months from the Trinity Refinance Date upon the satisfaction of certain milestones set forth in the 2025 Trinity Term Loan

Previous wording

In April 2023, we entered into a securities purchase agreement, or the SSI Securities Purchase Agreement, with two affiliates of SSI Strategy Holdings LLC, or SSI, named therein, or the SSI Investors, pursuant to which we issued and sold to the SSI Investors in a private placement, or the SSI Private Placement, 705,218 shares of our common stock, or the SSI Shares, and warrants, or the SSI Warrants, to purchase an aggregate of 525,000 shares of our common stock, or the Warrant Shares. SSI provides certain consulting services to us. Each SSI Warrant has an exercise price of $0.7090 per Warrant Share. The SSI Warrants issued in the SSI Private Placement provide that the holder of the SSI Warrants will not have the right to exercise any portion of its SSI Warrants until the achievement of certain clinical and regulatory milestones related to our clinical programs. Gross proceeds of the SSI Private Placement were $0.5 million. During the year ended December 31, 2025, SSI exercised all 316,667 vested and outstanding Warrant Shares. We received proceeds of $0.2 million upon exercise.

Current wording

In April 2023, we entered into a securities purchase agreement, or the SSI Securities Purchase Agreement, with two affiliates of SSI Strategy Holdings LLC, or SSI, named therein, or the SSI Investors, pursuant to which we issued and sold to the SSI Investors in a private placement, or the SSI Private Placement, 705,218 shares of our common stock, or the SSI Shares, and warrants, or the SSI Warrants, to purchase an aggregate of 525,000 shares of our common stock, or the Warrant Shares. SSI provides certain consulting services to us. Each SSI Warrant has an exercise price of $0.7090 per Warrant Share. The SSI Warrants issued in the SSI Private Placement provide that the holder of the SSI Warrants will not have the right to exercise any portion of its SSI Warrants until the achievement of certain clinical and regulatory milestones related to our clinical programs. Gross proceeds of the SSI Private Placement were $0.5 million. During the year ended December 31, 2025, SSI exercised all 316,667 vested and outstanding Warrant Shares. We received proceeds of $0.2 million upon exercise. There are no outstanding SSI Warrants as of June 30, 2026.

Previous wording

On May 28, 2025, we entered into an underwriting agreement, or 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, or, collectively, the Underwriters, to issue and sell 46,868,687 shares of our common stock and pre-funded warrants to purchase 25,858,586 shares of our common stock, or the May 2025 Pre-Funded Warrants, pursuant to an effective shelf registration statement on Form S-3 and a related prospectus and prospectus supplement, or the May 2025 Offering. The offering price to the public was $2.75 per share of common stock and $2.749 per May 2025 Pre-Funded Warrant, which is the price to the public of each share of common stock sold in the May 2025 Offering, minus the $0.001 exercise price per May 2025 Pre-Funded Warrant. The Underwriters purchased the shares and the May 2025 Pre-Funded Warrants from us pursuant to the May 2025 Underwriting Agreement at a price of $2.585 per share and $2.584 per pre-funded warrant, respectively. The initial closing of the May 2025 Offering occurred on May 30, 2025. In addition, we granted the Underwriters an option to purchase, for a period of 30 days, up to an additional 10,909,090 shares of our common stock, which the Underwriters exercised in full on June 6, 2025. The total net proceeds received from the May 2025 Offering were $215.6 million after deducting underwriting discounts, commissions and other offering expenses payable by us.

Current wording

On June 24, 2026, we entered into an underwriting agreement, or the June 2026 Underwriting Agreement, with Jefferies LLC and Goldman Sachs & Co., LLC, as representatives of the several underwriters set forth therein, or collectively, the Underwriters, to issue and sell 32,500,001 shares of our common stock and, in lieu of common stock to certain investors, pre-funded warrants to purchase 833,333 shares of its common stock in an underwritten public offering. or the June 2026 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 $6.00 per share of common stock and $5.999 per pre-funded warrant, which was the price to the public of each share of common stock sold in the June 2026 Offering minus the $0.001 exercise price per pre-funded warrant. The Underwriters purchased the shares and the pre-funded warrants from us pursuant to the June 2026 Underwriting Agreement at a price of $5.64 per share and $5.639 per pre-funded warrant, respectively. The closing of the June 2026 Offering occurred on June 26, 2026. In addition, we granted the Underwriters an option to purchase, for a period of 30 days, up to an additional 5,000,000 shares of common stock, which the Underwriters exercised in full on June 26, 2026. The total net proceeds from the June 2026 Offering were approximately $215.6 million, including the proceeds from the Underwriter’s option, after deducting underwriting discounts and commissions and offering expenses payable by us.

Previous wording

As of March 31, 2026, our material cash requirements consisted of $27.6 million in total lease payments under our noncancelable leases for equipment, laboratory space and office space. These leases are described in further detail in Note 5 to our unaudited condensed consolidated financial statements located in “Part I – Financial Information, Item 1. Financial Statements” in this Quarterly Report on Form 10-Q. Our most significant purchase commitments consist of approximately $34.1 million in cancellable purchase obligations to manufacturing vendors, CROs and other clinical trial vendors.

Current wording

As of June 30, 2026, our material cash requirements consisted of $9.8 million in total lease payments under our noncancelable leases for equipment, laboratory space and office space. These leases are described in further detail in Note 5 to our unaudited condensed consolidated financial statements located in “Part I – Financial Information, Item 1. Financial Statements” in this Quarterly Report on Form 10-Q. Our most significant purchase commitments consist of approximately $39.3 million in cancellable purchase obligations to manufacturing vendors, CROs and other clinical trial vendors.

Previous wording

We believe that our existing cash and cash equivalents will enable us to fund our operating expenses and capital requirements into 2028. We will require additional capital to fund the research and development of our product candidates, to fund our manufacturing activities, to fund precommercial activities of our programs and for working capital and general corporate purposes. The assessment of our ability to meet our future obligations is inherently judgmental, subjective and susceptible to change.

Current wording

We believe that our existing cash and cash equivalents will enable us to fund our operating expenses and capital requirements into the second half of 2028. We will require additional capital to fund the research and development of our product candidates, to fund our manufacturing activities, to fund precommercial activities of our programs and for working capital and general corporate purposes. The assessment of our ability to meet our future obligations is inherently judgmental, subjective and susceptible to change.

Previous wording

The following table shows a summary of our cash flows for the three months ended March 31, 2026 and 2025 (in thousands):

Current wording

The following table shows a summary of our cash flows for the six months ended June 30, 2026 and 2025 (in thousands):

Previous wording

For the three months ended March 31, 2026, our net cash used in operating activities of $40.9 million primarily consisted of a net loss of $42.4 million, primarily attributable to our spending on research and development expenses. The net loss of $42.4 million was partially offset by adjustments for non-cash items, primarily stock-based compensation expense of $5.5 million and other non-cash items of $0.6 million, net. Additional cash used in operating assets and liabilities of $4.6 million was primarily attributable to decreases in accrued expenses and other liabilities.

Current wording

For the six months ended June 30, 2026, our net cash used in operating activities of $81.3 million primarily consisted of a net loss of $89.0 million, primarily attributable to our spending on research and development expenses. The net loss of $89.0 million was partially offset by adjustments for non-cash items of $7.6 million. Non-cash adjustments are comprised of stock-based compensation expense of $11.4 million and other non-cash items of $1.4 million, net, partially offset by non-cash net gain on lease termination of $5.1 million. Additional cash provided by operating assets and liabilities of $0.1 million was primarily attributable to increases in accounts payable and partially offset by decreases in accrued expenses and other liabilities and increases in prepaid expenses.

Previous wording

For the three months ended March 31, 2025, our net cash used in operating activities of $22.0 million primarily consisted of a net loss of $21.5 million, primarily attributable to our spending on research and development expenses. The net loss of $21.5 million was partially offset by adjustments for non-cash items, primarily stock-based compensation expense of $3.3 million and other non-cash items of $0.8 million, net. Additional cash used in operating assets and liabilities of $4.6 million was primarily attributable to deferred revenue and accrued expenses and other liabilities.

Current wording

For the six months ended June 30, 2025, our net cash used in operating activities of $42.2 million primarily consisted of a net loss of $48.4 million, primarily attributable to our spending on research and development expenses. The net loss of $48.4 million was partially offset by adjustments for non-cash items, primarily stock-based compensation expense of $6.5 million and other non-cash items of $2.1 million, net. Additional cash used in operating assets and liabilities of $2.3 million was primarily attributable to a decrease in deferred revenue of $4.3 million, partially offset by an increase in accounts payable of $3.9 million.

Previous wording

During the three months ended March 31, 2026, investing activities used $3.0 million of cash primarily attributable to the regulatory milestone payment of $3.0 million paid to Abeona pursuant to the Abeona Rett Agreement. This milestone payment related to the first patient dosed with TSHA-102 in the Phase 1/2 Part B REVEAL pivotal trial that occurred in 2025 and was paid in 2026.

Current wording

During the six months ended June 30, 2026, investing activities used $3.0 million of cash primarily attributable to the regulatory milestone payment of $3.0 million paid to Abeona pursuant to the Abeona Rett Agreement. This milestone payment related to the first patient dosed with TSHA-102 in the Phase 1/2 Part B REVEAL pivotal trial that occurred in 2025 and was paid in 2026.

Previous wording

During the three months ended March 31, 2025, investing activities used $0.4 million of cash primarily attributable to the purchase of lab equipment and computer equipment.

Current wording

During the six months ended June 30, 2025, investing activities used $0.3 million of cash primarily attributable to the purchase of lab equipment and computer equipment.

Previous wording

During the three months ended March 31, 2026, financing activities provided $0.7 million of cash, which is primarily attributable to proceeds from common stock issuances upon the exercise of stock options and the Employee Stock Purchase Plan, or ESPP.

Current wording

During the six months ended June 30, 2026, financing activities provided $217.4 million of cash, which is primarily attributable to the closing of the June 2026 Offering and proceeds from common stock issuances upon the exercise of stock options and the Employee Stock Purchase Plan, or ESPP.

Previous wording

We are a “smaller reporting company,” meaning that the market value of our shares held by non-affiliates is less than $700 million and our annual revenue was less than $100 million during the most recently completed fiscal year. We may continue to be a smaller reporting company if either (i) the market value of our shares held by non-affiliates is less than $250 million or (ii) our annual revenue was less than $100 million during the most recently completed fiscal year and the market value of our shares held by non-affiliates is less than $700 million. We will continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company, we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and smaller reporting companies have reduced disclosure obligations regarding executive compensation.

Current wording

We are eligible to use the requirements of a “smaller reporting company,” as defined in the Securities Exchange Act of 1934, as amended, or the Exchange Act. We may take advantage of certain of the scaled disclosures available to smaller reporting companies and will be able to take advantage of these scaled disclosures for so long as (i) the market value of our shares held by non-affiliates is less than $250 million or (ii) our annual revenue was less than $100 million during the most recently completed fiscal year and the market value of our shares held by non-affiliates is less than $700 million. Specifically, as a smaller reporting company, we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and smaller reporting companies have reduced disclosure obligations regarding executive compensation.