FDA Defers Action on Novel Pompe Disease Therapy Cipaglucosidase Alfa, AT-GAA Decision

The FDA has issued a Deferred Action Letter in regard to today's anticipated decision on AT-GAA for the treatment of late-onset Pompe disease (LOPD). Because of travel restrictions related to COVID-19, the site inspection at WuXi Biologics manufacturing site in China was obstructed, and because of the October, 29 PDUFA date, the agency deferred.

Aside from the inability to fulfill the site inspection, there was no other reason for the FDA deferral. The approval of the combination drug candidate's 2 components are still expected, according to a statement from developing company Amicus Therapeutics.

“We are now one step away from the necessary approvals for AT-GAA in the US. We continue to believe this is a question of ‘when’ not ‘if’ AT-GAA will be approved and we will continue to work with great urgency to support the FDA’s completion of the final plant inspection necessary for approval so that this important new treatment option is made available for people living with Pompe disease in the United States,” Bradley Campbell, President, Chief Executive Officer, Amicus Therapeutics, stated.

After the candidate was granted FDA Breakthrough Therapy Designation for this indication, the Pompe disease community was anticipating a final decision for AT-GAA's biologic component cipaglucosidase alfa, the second of the two-part combination therapy.

Clinical efficacy data demonstrated by the drug's phase 1/2 study supported the review acceleration. The unique recombinant human acid alpha-glucosidase (rhGAA) enzyme boasts optimized carbohydrate structures. The bis-phosphorylated mannose-6 phosphate (bis-M6P) glycans specifically enhance cell rentention while the integative administration of miglustat (AT2221) serves as a a stabilizer of cipaglucosidase alfa.

“We remain committed to bringing AT-GAA to as many people living with Pompe disease around the world as quickly as possible," Campbell said.

Listen to the latest episode of Rare Disease Report to learn more about Pompe disease and the future of the rare disease's treatment according to expert Barry Byrne, MD, PhD, Associate Chair of Pediatrics, Director of the Powell Gene Therapy Center, University of Florida; Chief Medical Advisor, Muscular Dystrophy Association.