Taysha Gene Therapies (TSHA) has announced encouraging progress in its TSHA-102 program, a gene therapy being developed for Rett syndrome. The company's Q3 2024 financial results highlighted that the high-dose treatment of TSHA-102 was well-tolerated in both adult and pediatric trials, with no serious adverse events reported. These findings pave the way for further clinical advancements and potential regulatory milestones.
FDA Endorsement and Manufacturing Advancement
A significant achievement for Taysha is the FDA's approval of the pivotal TSHA-102 product for use in the REVEAL trials. This approval was based on the successful demonstration of analytical comparability between the clinical product and the product derived from the final commercial manufacturing process. The FDA also endorsed the intended commercial manufacturing process, proposed analytical methods, and corresponding qualification and validation plans, including mechanism of action potency release assays. This endorsement signifies a major step forward in the development and potential commercialization of TSHA-102.
Clinical Trial Updates and Anticipated Milestones
Taysha's REVEAL trials are currently underway, evaluating the safety and efficacy of TSHA-102 in adolescent/adult and pediatric patients with Rett syndrome. As of the latest data cutoff, eight patients have been dosed in the REVEAL trials (low dose=4, high dose=4). The Independent Data Monitoring Committee (IDMC) has approved continued enrollment in cohort two (high dose) across both REVEAL Phase 1/2 trials, following review of available clinical data from the first two adolescent/adult patients and the first pediatric patient treated with the high dose of TSHA-102.
Clinical data from cohort two (high dose) and cohort one (low dose) of both REVEAL trials are expected in the first half of 2025. These data will provide critical insights into the potential therapeutic benefits of TSHA-102 in Rett syndrome patients.
Financial Position and Future Outlook
Taysha reported a net loss of $25.5 million for the three months ended September 30, 2024, compared to a net loss of $117.1 million for the three months ended September 30, 2023. Research and development expenses were $14.9 million for the three months ended September 30, 2024, compared to $11.8 million for the three months ending September 30, 2023. As of September 30, 2024, Taysha had $157.7 million in cash and cash equivalents, which is expected to support planned operating expenses and capital requirements into the fourth quarter of 2026.
TSHA-102: Addressing the Genetic Root of Rett Syndrome
TSHA-102 is designed as a one-time treatment to address the genetic root cause of Rett syndrome by delivering a functional form of MECP2 to cells in the CNS. The therapy utilizes a novel miRNA-Responsive Auto-Regulatory Element (miRARE) technology designed to mediate levels of MECP2 in the CNS on a cell-by-cell basis without risk of overexpression. TSHA-102 has received Regenerative Medicine Advanced Therapy, Fast Track and Orphan Drug and Rare Pediatric Disease designations from the FDA, Orphan Drug designation from the European Commission and Innovative Licensing and Access Pathway designation from the Medicines and Healthcare products Regulatory Agency.
About Rett Syndrome
Rett syndrome is a rare neurodevelopmental disorder caused by mutations in the X-linked MECP2 gene encoding methyl CpG-binding protein 2 (MeCP2), which is essential for regulating neuronal and synaptic function in the brain. The disorder is characterized by loss of communication and hand function, slowing and/or regression of development, motor and respiratory impairment, seizures, intellectual disabilities and shortened life expectancy. Currently, there are no approved disease-modifying therapies that treat the genetic root cause of the disease.
