Taysha Gene Therapies Q2 Earnings Call Highlights

Taysha Gene Therapies NASDAQ: TSHA said it completed dosing in its REVEAL pivotal trial and ASPIRE trial for TSHA-102, its gene therapy candidate for Rett syndrome, while preparing for a potential biologics license application submission. Chief Executive Officer Sean Nolan said the company dosed 17 patients in the over-enrolled REVEAL pivotal trial and four patients ages 2 to under 4 in the ASPIRE study. The REVEAL trial enrolled pediatric, adolescent and adult patients, which Nolan said reflects the broader Rett syndrome population.

The company plans to conduct a six-month interim analysis after all 17 REVEAL pivotal-trial patients complete six months of follow-up. Taysha said the analysis could form the basis of a planned BLA submission and potentially accelerate its filing timeline by at least two quarters compared with waiting for 12-month data. The company expects to report top-line interim data and FDA feedback on its BLA pathway in the first half of 2027.

Sukumar Nagendran, Taysha’s president and head of research and development, discussed longer-term data from Part A of the REVEAL Phase I/II trial presented at the International Rett Syndrome Foundation scientific meeting. As of a May 2026 data cutoff, all 12 treated patients had at least 12 months of follow-up. Using the FDA-aligned developmental milestone assessment criteria planned as the pivotal trial’s primary endpoint, Taysha reported that 75% of Part A patients were responders at three months, 83% were responders at six months and all 12 patients were responders by 12 months. The company said the FDA-aligned minimum efficacy threshold for the pivotal trial is a 33% response rate. Patients achieved 31 total developmental milestones, including 16 among six pediatric patients and 15 among six adolescent and adult patients, according to Nagendran. At 12 months and beyond, the company recorded 310 functional gains across communication, fine motor, gross motor and autonomic domains, averaging 26 gains per patient.

Taysha also presented a Rett syndrome natural-history analysis indicating that developmental progress plateaus after age 6 and that the chance of gaining or regaining a lost developmental milestone declines to less than 6.7%. Nagendran said the data support REVEAL’s minimum enrollment age of 6 and help distinguish observed trial gains from the disease’s expected natural history. The company additionally cited a methods study supporting the developmental milestone assessment as a psychometrically valid and FDA-supported endpoint for a single-arm interventional study.