Previously disclosed 100% response rate across all 10 patients in Part A for pivotal trial primary endpoint of gain/regain of ≥ one natural history defined developmental milestone assessed via video-evidenced review by independent central raters New supplemental analysis of validated, structured efficacy scales provides supportive evidence of additional functional gains, with 100% of patients demonstrating multiple skill gains/improvements outside the natural history defined developmental milestones Finding ...

Core Insights - Taysha Gene Therapies has commenced site activation for the REVEAL pivotal trial, with patient enrollment expected to begin in Q4 2025 following regulatory feedback from Health Canada and the FDA [1][3][4] - The TSHA-102 treatment has shown a 100% response rate in the primary endpoint of gaining or regaining developmental milestones in the Phase 1/2 trials, indicating strong therapeutic potential [1][5][10] - The company has successfully raised $230 million through a public follow-on offering, extending its cash runway into 2028 [1][8] Company Updates - Taysha Gene Therapies is focused on advancing AAV-based gene therapies for severe monogenic diseases, particularly targeting Rett syndrome with its lead product TSHA-102 [2][12] - The REVEAL pivotal trial is designed as a single-arm, open-label study, with a primary endpoint assessing the percentage of patients who gain or regain developmental milestones [4][5] - The company has received various designations from the FDA, including Regenerative Medicine Advanced Therapy and Fast Track, which facilitate the development of TSHA-102 [10][12] Financial Performance - For Q2 2025, Taysha reported a net loss of $26.9 million, compared to a net loss of $20.9 million in Q2 2024, with research and development expenses increasing to $20.1 million [7][15] - Cash and cash equivalents as of June 30, 2025, were $312.8 million, bolstered by the recent follow-on offering [8][16] - General and administrative expenses rose to $8.6 million in Q2 2025, primarily due to higher legal and professional fees [6][15]

Core Insights - Taysha Gene Therapies is advancing its TSHA-102 program for Rett syndrome, focusing on the potential to improve developmental milestones and quality of life for patients [2][3] - The company will present recent updates on TSHA-102 at the 2025 International Rett Syndrome Foundation Scientific Meeting in Boston [2][4] - TSHA-102 is a gene therapy designed to address the genetic root cause of Rett syndrome by delivering a functional form of the MECP2 gene [5] Company Overview - Taysha Gene Therapies is a clinical-stage biotechnology company specializing in AAV-based gene therapies for severe monogenic diseases of the central nervous system [7] - The company has received multiple designations from the FDA for TSHA-102, including Regenerative Medicine Advanced Therapy and Fast Track designations [5] - Taysha aims to address significant unmet medical needs in the field of gene therapy, leveraging its experienced management team and proven AAV9 capsid technology [7] Disease Context - Rett syndrome is a rare neurodevelopmental disorder primarily affecting females, characterized by loss of communication, motor function, and intellectual disabilities [6] - The disorder is caused by mutations in the MECP2 gene, with an estimated 15,000 to 20,000 patients affected in the U.S., EU, and U.K. [6] - Currently, there are no approved therapies that modify the disease's genetic root cause, highlighting the importance of TSHA-102 [6]

Core Insights - Taysha Gene Therapies announced positive clinical data for TSHA-102, a gene therapy for Rett syndrome, showing a 100% responder rate in patients aged 6-21 years, with all patients gaining or regaining at least one developmental milestone post-treatment [1][2][5] - The FDA has provided written alignment on the pivotal Part B trial design for TSHA-102, which is expected to begin in Q3 2025 [1][4][12] - The analysis of natural history data indicates that patients aged six years and older are in a developmental plateau, with a likelihood of gaining new milestones being exceedingly low without treatment [1][6] Company Overview - Taysha Gene Therapies is a clinical-stage biotechnology company focused on AAV-based gene therapies for severe monogenic diseases of the CNS, with TSHA-102 as its lead program targeting Rett syndrome [8][10] - TSHA-102 is designed as a one-time treatment that delivers a functional form of the MECP2 gene to address the genetic root cause of Rett syndrome [8][9] Clinical Trial Details - The pivotal Part B trial will be a single-arm, open-label study with an intended enrollment of 15 patients, assessing developmental milestone gain/regain [1][6] - The primary endpoint of the trial is the gain or regain of at least one defined developmental milestone, with independent central raters evaluating outcomes based on video evidence [6] - Safety data from the ongoing REVEAL Phase 1/2 trials indicated no treatment-related serious adverse events or dose-limiting toxicities [1][5][6] Efficacy and Safety Findings - In the REVEAL Part A trial, 100% of patients treated with TSHA-102 achieved developmental milestones, with high-dose cohorts showing faster and more pronounced improvements compared to low-dose cohorts [1][5][6] - Improvements were observed across multiple clinician-assessed outcome measures, including the Revised Motor Behavior Assessment and Clinician Global Impression – Improvement [6] Future Plans - The company plans to submit the pivotal trial protocol and statistical analysis plan as an amendment to the IND application within the current quarter [2][12] - Taysha anticipates initiating pivotal trial activities in Q3 2025, following FDA guidance [1][12]

Core Insights - Taysha Gene Therapies has made significant regulatory and clinical progress with its TSHA-102 program for Rett syndrome, having reached alignment with the FDA on key elements of the pivotal Part B trial design [3][4] - The FDA has advised the company to submit the pivotal Part B trial protocol and statistical analysis plan as an amendment to the IND application, which is expected to expedite study initiation and registration [3][4] - TSHA-102 has shown to be generally well tolerated in patients, with no treatment-related serious adverse events or dose-limiting toxicities reported in the initial cohorts [4] Regulatory Progress - The company achieved alignment with the FDA on the pivotal Part B trial design for TSHA-102, following discussions under the Regenerative Medicine Advanced Therapy (RMAT) pathway [4] - The FDA's guidance allows Taysha to submit the trial protocol directly as an IND amendment, eliminating the need for a formal end-of-phase meeting, which may accelerate the process [3][4] Clinical Data - As of April 10, 2025, TSHA-102 has been administered to 10 patients (6 in the high dose cohort and 4 in the low dose cohort) across two REVEAL Phase 1/2 trials, with no serious adverse events or dose-limiting toxicities reported [4] - A comprehensive update on the pivotal trial design, natural history data analysis, and clinical data from the REVEAL trials is anticipated in Q2 2025 [4][13] Financial Highlights - For Q1 2025, research and development expenses were $15.6 million, down from $20.7 million in Q1 2024, primarily due to reduced manufacturing activities [7] - General and administrative expenses increased to $8.2 million in Q1 2025 from $7.1 million in Q1 2024, attributed to higher compensation and legal fees [8] - The net loss for Q1 2025 was $21.5 million, or $0.08 per share, compared to a net loss of $24.1 million, or $0.10 per share, in Q1 2024 [9][17] Cash Position - As of March 31, 2025, Taysha had $116.6 million in cash and cash equivalents, which is expected to support operations into Q4 2026 [9][19] Upcoming Events - Taysha will present three abstracts related to TSHA-102 at the 2025 International Rett Syndrome Foundation Scientific Meeting scheduled for June 9-11, 2025 [4][5]