What is MPS VI?
MPS VI (mucopolysaccharidosis VI), also known as Maroteaux-Lamy Syndrome, is an inherited lysosomal storage disorder caused by the deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B), an enzyme normally required for the breakdown of certain complex carbohydrates known as glycosaminoglycans (GAGs). If the enzyme is not present in sufficient quantities, the normal breakdown of GAGs is incomplete or blocked. The cell is unable to excrete the GAG residues which then accumulate in the lysosomes of the cell. This accumulation disrupts the cell’s normal functioning and gives rise to the physical manifestations of the disease.
Approximately 1,100 patients in developed countries have MPS VI. It is inherited in an autosomal recessive manner, affects males and females equally, and in most cases, both parents of an affected child are asymptomatic carriers of the disease. MPS VI is a clinically heterogeneous disease with a wide variation in the rate of disease progression, the severity of symptoms, and the organ systems affected. Unlike MPS I, MPS VI does not typically affect intelligence level.
Diagnosis of MPS VI
While patients with a rapidly progressing clinical presentation of MPS VI are usually diagnosed by one to five years of age, those with the more slowly progressing disease may be misdiagnosed. Over time the disease progresses, and depending on the degree of enzyme deficiency, patients experience severe disabilities and possibly early death—factors underscoring the importance of early diagnosis.
The following are some of the features and symptoms associated with MPS VI:
- Short stature
- Macrocephaly (large head)
- Progressively coarse facial features
- Communicating hydrocephalus
- Spinal cord compression
- Carpal tunnel syndrome
- Corneal clouding
- Impaired vision
- Recurrent otitis media
- Impaired hearing
- Recurrent sinopulmonary infections
- Upper airway obstruction
- Sleep apnea
- Reduced pulmonary function
- Cardiac abnormalities and valvular disease
- Umbilical and inguinal hernias
- Reduced joint range of motion
- Dysostosis mutiplex (bone deformities)
- Malaise and reduced endurance
Treatment Options for MPS VI
Historically, treatment of MPS VI has been limited primarily to palliative care that addresses the multi-systemic symptoms of the disease. Today, however, there is an approved therapeutic option specifically for the treatment of MPS VI—enzyme replacement therapy with Naglazyme® (galsulfase). Naglazyme is approved in the United States, the European Union, Australia, Brazil, Croatia, Japan, South Korea, Switzerland, and Belarus for the treatment of MPS VI.
For additional information about MPS VI, please visit the following websites and others listed in the Patient/Physician Resource Library:
- www.MPSsociety.org The National MPS Society (U.S.)
- www.MPSsociety.co.uk Society for Mucopolysaccharide Diseases (U.K.)
Naglazyme is indicated for patients with mucopolysaccharidosis VI (MPS VI). Naglazyme has been shown to improve walking and stair-climbing capacity.
Important Safety Information
The most common adverse events in patients treated with Naglazyme were headache, fever, joint pain, vomiting, upper respiratory infections, abdominal pain, diarrhea, ear pain, cough, and ear infections. Severe reactions included swollen blood vessels, low blood pressure, difficulty breathing, respiratory distress, stopping breathing, and hives.
The most common symptoms of infusion reactions included fever, chills/shakes, headache, rash, and mild to moderate hives. Nausea, vomiting, elevated blood pressure, chest pain, abdominal pain, malaise, and joint pain were also reported.
No patients discontinued Naglazyme treatment because of reactions. Nearly all patients developed antibodies as a result of the treatment, but the level of immune response did not correlate with the severity of the adverse reaction.
Because antihistamine use may increase the risk of stopping breathing, airways should be checked to ensure they are not blocked or obstructed. Treatment may be delayed if you have a fever or respiratory illness.
To report SUSPECTED ADVERSE REACTIONS, contact BioMarin Pharmaceutical Inc. at 1-866-906-6100, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Naglazyme is available by prescription only. To learn more, please visit www.naglazyme.com for full prescribing information. If you have any questions about this information, please talk with your doctor.