Sanofi’s Nexviazyme Meets All Endpoints in Phase 3 Baby-COMET Study for Infantile-Onset Pompe Disease

Sanofi has reported positive topline results from the Phase 3 Baby-COMET study (NCT04910776), demonstrating that Nexviazyme (avalglucosidase alfa) met its primary endpoint in infants with infantile-onset Pompe disease (IOPD). The findings support the company’s plan to seek U.S. regulatory approval for the enzyme replacement therapy in this severe pediatric indication during the second half of 2026.

The single-arm, open-label international study evaluated Nexviazyme in treatment-naïve infants aged six months or younger. The primary endpoint, survival without invasive ventilation after 52 weeks of treatment, was achieved. The study also met all secondary endpoints, including ventilator-free survival at 12 and 18 months of age and improvements across multiple measures of disease progression.

The full dataset will be presented on July 8, 2026, at the 19th International Congress on Neuromuscular Diseases in Florence, Italy.

Nexviazyme targets the underlying enzyme deficiency

Pompe disease is a rare inherited lysosomal storage disorder caused by deficiency of the acid alpha-glucosidase (GAA) enzyme. Reduced GAA activity leads to glycogen accumulation in skeletal and cardiac muscle, resulting in progressive muscle damage.

Infantile-onset Pompe disease represents the most aggressive form of the disorder, with symptoms appearing during the first months of life. Without treatment, affected infants rapidly develop cardiomyopathy, respiratory failure, profound muscle weakness, and often die within the first year.

Nexviazyme is an enzyme replacement therapy engineered to enhance cellular uptake through the mannose-6-phosphate receptor pathway. Compared with alglucosidase alfa, it contains approximately 15-fold higher mannose-6-phosphate content, which may improve delivery of the replacement enzyme into affected tissues and promote glycogen clearance.

Baby-COMET met efficacy and safety objectives

The Phase 3 Baby-COMET trial enrolled 17 treatment-naïve infants aged 12 months or younger with infantile-onset Pompe disease. Participants received intravenous Nexviazyme 40 mg/kg every other week.

Beyond meeting the primary endpoint of invasive ventilator-free survival at week 52, investigators reported numerical improvements in key markers of disease progression, including left ventricular mass Z-score, Alberta Infant Motor Scale score, and urinary glucose tetrasaccharide levels.

Nexviazyme demonstrated a safety profile consistent with previous studies. No serious treatment-related adverse events, treatment-related deaths, or treatment discontinuations occurred during the study. Infusion-associated reactions were reported in 29.4% of participants and were considered manageable.

Results strengthen evidence for earlier treatment

Commenting on the findings, Dr. Priya S. Kishnani of Duke University Medical Center said early treatment remains critical because infantile-onset Pompe disease progresses rapidly within the first weeks of life. She noted that the Baby-COMET results demonstrated encouraging ventilator-free survival alongside improvements in cardiac and motor outcomes, supporting the potential role of avalglucosidase alfa in this high-risk patient population.

Christopher Corsico, Global Head of Development at Sanofi, said the findings reinforce evidence generated across the company’s Pompe disease development program and could expand access to Nexviazyme for infants with limited treatment options.

Regulatory submission planned in 2026

Nexviazyme is currently approved in the United States for late-onset Pompe disease in patients aged one year and older following its 2021 approval. In Europe, the therapy is marketed as Nexviadyme and has been approved since 2022 for both late-onset and infantile-onset Pompe disease.

The Baby-COMET data will support Sanofi’s planned U.S. label expansion application for infantile-onset Pompe disease in the second half of 2026. Until regulatory review is completed, avalglucosidase alfa remains investigational for this indication in the United States.

Reference

Press Release: Sanofi’s Nexviazyme met all primary and secondary endpoints in infantile-onset Pompe disease phase 3 study