My research concerns different therapeutic strategies in Pompe disease, a rare lysosomal storage disorder manifesting as a progressive myopathy. Currently, patients with Pompe disease can be treated with enzyme replacement therapy (ERT), where a recombinant version of the missing enzyme (acid α-glucosidase) is administered intravenously every one to two weeks. Two new types of ERT have recently been approved and are reimbursed in the Netherlands as of February 2025 for adult, late-onset Pompe patients. Prior to this reimbursement, we were already studying the effect of switching late-onset Pompe patients deteriorating on the current treatment (alglucosidase alfa) to one of the new therapies (avalglucosidase alfa, AVA study). Additionally, now that reimbursement for the new ERTs is granted, we are planning to switch the majority of our patients to these new treatments and will evaluate the effect of this switch in our patients as well. We are also planning to evaluate whether in some patients a dose frequency reduction of ERT (administration once every four instead of once every two weeks) is still effective and safe.