Sanofi (Nasdaq: SNY) reported that avalglucosidase alfa (Nexviazyme) met all primary and secondary endpoints in the Baby-COMET Phase III study in treatment-naïve infants with infantile-onset Pompe disease (IOPD). The trial potentially provides the clinical basis for a US label expansion that could extend Nexviazyme's reach into the most severe and time-critical patient population in Pompe disease — one where the only currently approved option is the older, less efficient enzyme replacement therapy (ERT) alglucosidase alfa.
Nexviazyme holds FDA approval for late-onset Pompe disease (LOPD) in patients one year of age and older, and European approval covering both LOPD and IOPD. In the US, however, IOPD treatment-naïve infants have been limited to Sanofi's own Myozyme (alglucosidase alfa), approved in 2006. Baby-COMET's results, if accepted by regulators, would allow Sanofi to replace or supplement the older molecule with a next-generation agent.
Trial results and design
Baby-COMET is a single-arm, open-label, international Phase III study enrolling 17 treatment-naïve pediatric patients with IOPD aged 12 months and younger. The primary endpoint — proportion of patients aged six months and younger who were alive and free of invasive ventilation at Week 52 — was met. All secondary endpoints were also met, including survival free of invasive ventilation at 12 and 18 months of age, and numerical improvements in left ventricular mass Z-score, Alberta Infant Motor Scale score, and urinary glucose tetrasaccharide at 52 weeks. Full data will be presented July 8, 2026 at the 19th International Congress on Neuromuscular Diseases in Florence.
The small cohort reflects the rarity and severity of IOPD, where rapid disease progression limits the feasibility of large controlled trials. The single-arm design, without a randomized comparator, means that efficacy interpretation is contextual rather than head-to-head. Cross-trial comparisons with historical alglucosidase alfa data are limited by differences in patient populations, endpoints, and era of treatment.