Gemma Biotherapeutics Doses First Patient in AAV Gene Therapy Trial for SMA1

PHILADELPHIA, Feb. 26, 2026 — Gemma Biotherapeutics (GEMMABio) announced that the first patient has been dosed in the Phase 1/2 CHARISMA (NCT07070999) clinical trial evaluating GB221, an investigational next-generation AAV gene therapy for spinal muscular atrophy type 1 (SMA1).

GB221 is the first next-generation AAV therapy for SMA1 delivered directly into the cerebrospinal fluid (CSF) via intracisterna-magna (ICM) injection, a route designed to enhance central nervous system (CNS) targeting. The program leverages proprietary CNS-directed AAV platform technology licensed from the University of Pennsylvania.

The AAV vector encodes a functional, codon-optimized SMN1 gene under control of a modified expression cassette engineered to reduce risks of overexpression-related toxicities and sensory neurotoxicity. The study will assess safety, tolerability, and preliminary efficacy in pediatric patients aged two weeks to less than 12 months, including both symptomatic and presymptomatic infants.

CEO James M. Wilson, MD, PhD highlighted the collaborative effort supporting the launch of the trial in Brazil, including partnerships with Oswaldo Cruz Foundation (Fiocruz), Casa dos Raros, ANVISA, Intrials, and the Hospital de Clínicas de Porto Alegre. Brazil serves as a regional hub for GEMMABio’s gene therapy programs under its broader collaboration with Fiocruz.

In parallel, the U.S. Food and Drug Administration has granted GB221 Rare Pediatric Disease Designation (RPDD). If approved, the AAV gene therapy could qualify GEMMABio for a Priority Review Voucher (PRV) under the reauthorized Rare Pediatric Disease Priority Review Voucher Program, currently extended through September 2029.