Long-term Outcome in Late-onset Pompe Disease Treated Beyond 36 Months (STIG-Pompe-Study)

The presentation and course of late-onset Pompe disease is much less foreseeable than the classic infantile form. Some patients experience a rapid worsening in skeletal muscle function leading to loss of ambulation and respiratory failure, while others progress less rapidly. So there is a more inconstant response to treatment in skeletal muscle and lung function in the long-term. Therefore, an unmet clinical need is the collection and analysis of long-term data of rhGAA enzyme replacement therapy (ERT) in late-onset Pompe disease patient aged 8 years and older. The principal goal of our investigator driven study is to gain conclusive insight in long-term outcome data beyond 36 months up to 10 years of ERT treatment. In addition we will collect biological samples from all patients for a future biomarker study including gene modifier search by genome and RNA seq (not part of this proposal). This study may provide clinicians and researchers with a better understanding of late-onset Pompe disease under long-term treatment, to the benefit of all patients affected with late-onset Pompe disease, as well as, individuals and families with related diseases.

Inclusion criteria

• Late-onset Pompe patients, aged over 8 years.
• The patient is willing and able to provide signed informed consent.
• The patient (and patient's legal guardian if patient is under 18 years of age) must have the ability to comply with the clinical protocol.
• Long-term Myozyme treatment beyond 36 months.
• Known GAA genotype.
• GAA activity (Dried blood spot testing, or other methods).

Exclusion criteria

• - The patient is concurrently participating in another clinical study using Myozyme or other treatment.
• The patient, in the opinion of the Investigator, is unable to adhere to the requirements of the study.
• The patient has clinically significant organic disease (with the exception of symptoms relating to Pompe disease), including clinically significant cardiovascular, hepatic, pulmonary, neurologic, or renal disease, or other medical condition, serious intercurrent illness, or extenuating circumstance that, in the opinion of the Investigator, precludes participation in the study or potentially decreases survival.