Safety Study of Recombinant Human Alpha-mannosidase for the Treatment of Patients With Alpha-mannosidosis

Inclusion criteria

• The patient must have a confirmed diagnosis of alpha-mannosidosis as defined by alpha-mannosidase activity < 10% of normal activity in blood leukocytes
• The patient must have an age at the time of screening ≥ 5 year and ≤ 20 years
• The patient must have physical ability to perform 6-minutes walk test (6MWT), 3 minute-stair climb test (3MSCT) and pulmonary lung function test (spirometry, body plethysmography).
• The patient must have the ability to mentally cooperate in the cognitive and motor function tests
• The patient must have the ability to hear and follow a request. Hearing aids can be worn.
• Patient or patient's legally authorized guardian(s) must provide signed, informed consent prior to performing any study-related activities (trial-related activities are any procedures that would not have been performed during normal management of the subject)
• The patient and his/her guardian(s) must have the ability to comply with the protocol

Exclusion criteria

• The patient cannot walk without support.
• Presence of known chromosomal abnormality and syndromes affecting psychomotor development, other than alpha-mannosidosis
• History of bone marrow transplantation
• Presence of known clinically significant cardiovascular, hepatic, pulmonary or renal disease or other medical conditions that, in the opinion of the Investigator, would preclude participation in the trial
• Presence of an ECHO with abnormalities within half a year that, in the opinion of the Investigator, would preclude participation in the trial
• Any other medical condition or serious intercurrent illness, or extenuating circumstance that, in the opinion of the investigator, would preclude participation in the trial
• Pregnancy
• Psychosis within the last 3 months