The 20th annual WORLDSymposium took place from February 4-9, 2024. During the course of the research conference, at least one presentation centered on data from the Phase 2 Mini-COMET long-term extension study and the Phase 3 Baby-COMET study. According to Market Screener, these studies evaluated Nexviazyme (avalglucosidase alfa) for infantile-onset Pompe disease. While there are existing therapies for late-onset Pompe disease, including Nexviazyme and Myozyme, there exists an unmet need for treatment options within the infantile-onset patient population.

People with Pompe disease, a rare genetic disorder, have GAA gene mutations. These mutations mean that people with this condition do not have enough GAA enzyme and cannot break down glycogen, a complex sugar. As a result, glycogen accumulates in cells, impairing muscle, tissue, and organ function. Nexviazyme is a MP6-enriched enzyme replacement therapy (ERT) that helps clear glycogen from tissues.

Infantile-onset Pompe disease is characterized by symptoms such as an enlarged liver, hypotonia (reduced muscle tone), muscle weakness, breathing difficulties, heart issues, and ptosis (drooping eyelids). Additionally, symptoms like ptosis can lead to vision loss and quality-of-life issues.

Is Nexviazyme an Option for Infantile-Onset Pompe Disease?

As described above, WORLDSymposium heard data from both the Phase 2 Mini-COMET and Phase 3 Baby-COMET studies. The first study included 22 participants younger than 18 years old with infantile-onset Pompe disease. These participants had previously received Nexviazyme for 6+ months and were divded into three cohorts. The first two cohorts showed clinical decline on the treatment, while the third cohort had a suboptimal response while on the treatment.

Cohort 1 received 20mg/kg Nexviazyme bi-weekly, with Cohort 2 receiving 40mg/kg bi-weekly and Cohort 3 receiving either 20mg/kg or 40mg/kg bi-weekly OR 40mg/kg weekly. All participants later entered an extension period of the trial where they received 40mg/kg Nexviazyme bi-weekly for up to almost three years. Researchers found that Cohorts 2 and 3a (receiving 40mg/kg bi-weekly) saw improved ptosis.

The second study, which included 11 participants with infantile-onset Pompe disease, explored how safe and effective this treatment was. All participants were six months old and had previously never received treatment. Researchers found that Nexviazyme was safe and well-tolerated. Some patients did experience treatment-emergent reactions such as bronchitis, febrile convulsions, COVID-19, urinary tract infections, and elevated potassium levels in the blood.