FDA Approves Avalglucosidase Alfa-ngpt For Late-Onset Pompe Disease

Officials with the FDA have approved avalglucosidase alfa-ngpt (Nexviazyme, Sanofi) for the treatment of patients with late-onset Pompe disease, a debilitating condition impacting mobility and the ability to breathe.

The drug, which is indicated for patients aged 1 year and older, is an enzyme replacement therapy (ERT) designed to target the mannose-6-phosphate (M6P) receptor. This receptor is the key pathway for cellular uptake of enzyme replacement therapy in Pompe disease, according to a press release.

“Pompe disease is a debilitating and progressive condition that significantly inhibits mobility and breathing,” said Bill Sibold, MBA, executive vice president of Sanofi Genzyme, in the press release. “For decades, we’ve made it our responsibility to research how to target the M6P receptor, the key pathway for cellular uptake of enzyme replacement therapy.”

Pompe disease impacts approximately 3500 individuals in the United States and can present as either infantile-onset disease or late-onset disease. Infantile-onset Pompe disease is the most severe form with rapid onset, whereas late-onset Pompe disease progressively damages muscles over time.

Symptoms of late-onset Pompe disease can present at any age, although it can take 7 to 9 years to diagnose due to the wide spectrum of clinical presentations and progressive nature of the disease. As the disease progresses, patients may require mechanical ventilation to help with breathing or a wheelchair to assist with mobility.

The disease is caused by a genetic deficiency or dysfunction of the lysosomal enzyme acid alpha-glucosidase (GAA), which causes build-up of glycogen in muscle cells. This accumulation results in irreversible damage to the muscles, including those in the diaphragm that support respiratory function and skeletal muscles that affect mobility, functional endurance, and breathing.

The approval is based on the pivotal phase 3 COMET trial, in which avalglucosidase alpha-ngpt demonstrated improvements in respiratory function and walking distance measures in patients with late-onset Pompe disease. According to the press release, patients receiving avalglucosidase alpha-ngpt had a 2.9-point improvement in forced vital capacity percent-predicted at week 49 compared to baseline.

Measured function endurance with a 6-minute walk test was a key secondary endpoint of the trial. When compared to baseline, patients treated with avalglucosidase alpha-ngpt walked 32.2 meters further at week 49. Notably, patients treated with avalglucosidase alpha-ngpt walked 30 meters further than patients treated with alglucosidase alfa at week 49.

During the double-blind active-controlled period of 49 weeks, serious adverse reactions were reported in 2 (2%) of the patients treated with avalglucosidase alpha-ngpt and in 3 (6%) of the patients treated with alglucosidase alfa. The most frequently reported adverse reactions in patients treated with avalglucosidase alpha-ngpt were headache, pruritus, nausea, hives, and fatigue.

Furthermore, infusion associated reactions were reported in 13 (25%) of the avalglucosidase alpha-ngpt treatment recipients and in 16 (33%) of patients treated with alglucosidase alfa. Infusion-associated reactions reported in more than 1 patient receiving avalglucosidase alpha-ngpt were mild to moderate and included headache, diarrhea, itching, hives, and rash. None of these infusion-associated reactions were severe.

The drug is administered as a monotherapy every 2 weeks and the recommended dose is based on body weight. It is expected to be available in the United States in the coming weeks.

“Nexviazyme is a new and exciting therapeutic option for people with late-onset Pompe disease,” said Mazen M. Dimachkie, MD, FAAN, FANA, chief of the Neromuscular Division and executive vice chair of the Department of Neurology at the University of Kansas Medical Center, in the press release. “The phase 3 study results showed meaningful improvements in respiratory function and walking distance, which are impactful in this serious condition.”

REFERENCE

FDA approves Nexviazyme (avalglucosidase alfa-ngpt), an important new treatment option for late-onset Pompe disease. News release. Sanofi; August 6, 2021. Accessed August 6, 2021. https://www.sanofi.com/en/media-room/press-releases/2021/2021-08-06-17-42-21-2276588