Compelling Clinical Efficacy Signals in REVEAL Part A
REVEAL Part A reported a 100% response rate among the 10 treated patients across low- and high-dose cohorts, with an 83% response rate at six months in the high-dose group (5 of 6). Management reported an average of ~19 developmental milestone gains per patient from a 32-milestone set, sustained and deepening over time.
Pivotal and Pediatric Safety Trials Initiated with Favorable Tolerability
Initiated the REVEAL pivotal trial in 2025 and have dosed multiple patients with enrollment advancing; ASPIRE safety-focused trial cleared by FDA to enroll three females aged 2 to <4 years. No treatment-related serious adverse events or dose-limiting toxicities observed across REVEAL Phase 1/2 and pivotal trials as of the March 2026 data cutoff.
Regulatory Progress — FDA Breakthrough and Written Alignments
Received FDA Breakthrough Therapy designation for TSHA-102 and secured written FDA alignment on REVEAL pivotal and ASPIRE trial designs, a six-month interim analysis for the pivotal trial, as well as CMC comparability approach and PPQ strategy — enabling pooling of data across trials to support a BLA.
CMC and Manufacturing Alignment
FDA endorsed the proposed process performance qualification (PPQ) campaign, stability package, and potency assay strategy; management plans to initiate BLA-enabling PPQ lots in 2026 with completion of PPQ lots expected by year-end, supporting a streamlined BLA timeline alongside pivotal data.
Commercial Readiness and Market Opportunity
Market research showed high anticipated demand from clinicians and caregivers and a strong preference for intrathecal administration for scalability and outpatient delivery. Company estimates 15,000–20,000 Rett patients in U.S./EU/UK (6,000–9,000 in U.S.) and has begun building commercial leadership with the appointment of Brad Martin as SVP, Market Access and Value.
Cash Position and Near-Term Financing
As of 12/31/2025, cash and cash equivalents were $319.8 million. The company raised $50.0 million in Q4 2025 via its ATM program and expects current cash resources to fund planned operating expenses into 2028.
Planned Near-Term Data Milestones
Company expects a REVEAL Part A update in Q2 with 12 patients and a minimum of 12 months of follow-up, plus a six-month interim analysis for the REVEAL pivotal once all pivotal patients reach six months — providing multiple potential regulatory pathways toward BLA submission.