This clinical trial is focused on studying the long-term safety and effectiveness of a treatment for Pompe disease, specifically in adults with the late-onset form of the disease. Pompe disease is a rare genetic disorder that affects muscle function due to the buildup of a complex sugar called glycogen in the body’s cells. The treatment being studied involves two medications: ATB200 and AT2221. ATB200 is administered through an intravenous (IV) injection, which means it is given directly into a vein, while AT2221 is taken orally in the form of a capsule. The purpose of this study is to assess how safe and tolerable these medications are when used together over a long period.

Participants in the study will receive the treatment and be monitored for any side effects or changes in their health. The study will track various health indicators, such as the distance a participant can walk in six minutes, muscle strength, and overall physical function. These measures help researchers understand how the treatment affects the participants’ ability to perform daily activities and their overall quality of life. The study will also look at any potential immune reactions to the treatment, as well as changes in certain blood and urine markers that are related to Pompe disease.

The study is designed to last for several years, allowing researchers to gather comprehensive data on the long-term effects of the treatment. Participants will have regular check-ups and assessments to ensure their safety and to evaluate the treatment’s impact on their condition. This research aims to provide valuable insights into the management of Pompe disease and potentially improve treatment options for those affected by this condition.