The Lancet Neurology Publishes Pivotal Phase 3 PROPEL Study Results of AT-GAA in Late-Onset Pompe Disease

PHILADELPHIA – Amicus Therapeutics (Nasdaq: FOLD), a patient-dedicated global biotechnology company focused on developing and commercializing novel medicines for rare diseases, announced today that the data from the Phase 3 PROPEL pivotal trial, assessing the efficacy, safety and tolerability of AT-GAA in adults with late-onset Pompe disease compared to the standard of care, alglucosidase alfa, were published online in The Lancet Neurology. The manuscript includes data on the primary and key secondary endpoints, which were previously reported, as well as additional secondary endpoints. Based on the outcomes observed in the key domains of Pompe disease (muscle strength, pulmonary and motor function, patient-reported outcomes and biomarkers), the peer reviewed results determined the PROPEL data showed clinically meaningful improvements over standard of care, even among those who had been receiving approved therapy for at least 2 years, a subgroup that has been shown to plateau or decline after several years on treatment. AT-GAA is a two-component therapy consisting of cipaglucosidase alfa, an enhanced phosphorylated enzyme and miglustat, an enzyme stabilizer, thereby providing a different mechanism of action compared with alglucosidase alfa.

“Pompe disease is a rare genetic disease that causes premature death and has a debilitating effect on people’s lives. There is significant unmet medical need that persists within Pompe disease and patients are in need of new, effective and safe therapies. The outcomes of the PROPEL study demonstrate meaningful improvements in motor and respiratory functions in patients who are living with Pompe disease,” stated Prof. Benedikt Schoser, Professor of Neurology at Ludwig-Maximillians-University of Munich LMU Department of Neurology. “Results are particularly encouraging for the population switching from standard of care ERT to AT-GAA, who saw positive improvements in key manifestations of the disease.”

John F. Crowley, Chairman and Chief Executive Officer of Amicus Therapeutics, stated, “We are pleased that The Lancet Neurology has published our PROPEL pivotal data in adults living with late-onset Pompe disease. Based on the clinical data we have seen from the Phase 3 trial, in addition to the body of data that we have accumulated over nearly a decade of preclinical and clinical studies, we have generated a compelling data set that supports the potential of AT-GAA becoming the next standard of care in the treatment of Pompe disease. We are honored by this publication and would like to thank all of the investigators, patients and families who participated in the study.”

The U.S. Food and Drug Administration (FDA) previously granted Breakthrough Therapy designation for AT-GAA and accepted for review the Biologics License Application (BLA) and the New Drug Application (NDA). The FDA has set a Prescription Drug User Fee Act action date of May 29, 2022 for the NDA and July 29, 2022 for the BLA. In the EU, the Marketing Authorization Applications for AT-GAA have been submitted in the fourth quarter of 2021.

About AT-GAA

AT-GAA is an investigational two-component therapy that consists of cipaglucosidase alfa (ATB200), a unique recombinant human acid alpha-glucosidase (rhGAA) enzyme with optimized carbohydrate structures, particularly bis-phosphorylated mannose-6 phosphate (bis-M6P) glycans, to enhance uptake into cells, administered in conjunction with miglustat (AT2221), a stabilizer of cipaglucosidase alfa. In preclinical studies, AT-GAA was associated with increased levels of the mature lysosomal form of GAA and reduced glycogen levels in muscle, alleviation of the autophagic defect and improvements in muscle strength.

In addition, Amicus is enrolling an open-label, uncontrolled, multicenter study to evaluate the PK, safety, efficacy, and PD of AT-GAA in pediatric patients aged 0 to 18 years with LOPD (ATB200-04). More information, including a list of participating sites, is available at NCT03911505

About Pompe Disease

Pompe disease is an inherited lysosomal disorder caused by deficiency of the enzyme acid alpha-glucosidase (GAA). Reduced or absent levels of GAA levels lead to accumulation of glycogen in cells, which is believed to result in the clinical manifestations of Pompe disease. The disease can be debilitating and is characterized by severe muscle weakness that worsens over time. Pompe disease ranges from a rapidly fatal infantile form with significant impacts to heart function to a more slowly progressive, late-onset form primarily affecting skeletal muscle. It is estimated that Pompe disease affects approximately 5,000 to 10,000 people worldwide.

About Amicus Therapeutics

Amicus Therapeutics (Nasdaq: FOLD) is a global, patient-dedicated biotechnology company focused on discovering, developing and delivering novel high-quality medicines for people living with rare metabolic diseases. With extraordinary patient focus, Amicus Therapeutics is committed to advancing and expanding a robust pipeline of cutting-edge, first- or best-in-class medicines for rare metabolic diseases. For more information please visit the company’s website at, and follow us on Twitter and LinkedIn.


Andrew Faughnan
Executive Director, Investor Relations
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Diana Moore
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