According to a publication from KYN24, the Food and Drug Administration recently approved mucopolysaccharidosis type VII (MPS VII) drug Mepsevii for marketing and administration to patients in the United States.
Mucopolysaccharidosis (MPS) is a group of inherited progressive conditions characterized by the body’s inability to break down long molecules of sugar called mucopolysaccharides. These sugars, which in healthy individuals are easily broken down for energy, build up in high concentrations throughout the body.
The sugars build up in cells, blood, and even connective tissue. Symptoms and severity vary between the seven identified types of MPS, but all generally lead to a decline in mental and physical function over time. Even someone’s physical appearance can change as these sugar chains accumulate.
Mucopolysaccharidosis VII is just one of the identified forms of the disease. Severity between cases of MPS VII can vary, but it typically presents symptoms in early childhood – or even in the womb. The most serious cases are characterized by a prenatal buildup of fluids in the embryo – a condition known as hydrops fetalis. Most born with hydrops fetalis are stillborn or die soon after birth.
Those with MPS VII who survive infancy may develop a large head (macrocephaly) due to a buildup of fluid in the brain (hydrocephalus). Other serious implications include an elevated risk of liver or spleen enlargement, heart valve abnormalities, or gradual narrowing of the airway (contributing to frequent respiratory infections, and occasionally sleep apnea). Additionally, most patients will develop some kind of cognitive impairment – though not everyone experiences all of the known symptoms.
Mepsevii, an enzyme replacement therapy, was determined by the FDA to be safe and effective in pediatric and adult patients after several years of clinical testing. 23 participants, aged 5 months to 25 years, were to receive either a placebo or dose of Mepsevii once every two weeks for up to, and sometimes over, three years.
Ten of the patients who could still walk were assessed by their ability to walk for six minutes. After just 24 weeks, patients treated with Mepsevii were walking an average of 18 meters farther than their counterparts in the placebo arm in the same amount of time.
The results were impressive, and deemed statistically significant. Those who received optional follow-up treatments for up to another 120 weeks demonstrated continued improvement and stabilization of their condition. Two of the patients in the Mepsevii arm even experienced improvement in their lung function.
Though the FDA has approved Mepsevii for treatment of MPS VII, there is no indication that the drug is effective on forms of MPS VII affecting the central nervous system.
What do you think of this exciting news? Do you think it’s significant that central nervous system forms of MPS VII are unaffected by Mepsevii? Share your thoughts with Patient Worthy!