You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Vestronidase alfa and explain in detail?
Vestronidase alfa, sold under brand name Mepsevii, is a drug for the treatment of Sly syndrome.  It is a recombinant form of the human enzyme beta-glucuronidase.  It was approved in the United States in November 2017, to treat children and adults with an inherited metabolic condition called mucopolysaccharidosis type VII (MPS VII), also known as Sly syndrome. MPS VII is an extremely rare, progressive condition that affects most tissues and organs.The most common side effects after treatment with vestronidase alfa include infusion site reactions, diarrhea, rash (urticaria) and anaphylaxis (sudden, severe allergic reaction).The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. It was approved for use in the European Union in August 2018.

Medical uses
Mepsevii is indicated for the treatment of non-neurological manifestations of Mucopolysaccharidosis VII (MPS VII; Sly syndrome).

History
The safety and efficacy of vestronidase alfa were established in a clinical trial and expanded access protocols enrolling a total of 23 participants ranging from five months to 25 years of age. Participants received treatment with vestronidase alfa at doses up to 4 mg/kg once every two weeks for up to 164 weeks. Efficacy was primarily assessed via the six-minute walk test in ten participants who could perform the test. After 24 weeks of treatment, the mean difference in distance walked relative to placebo was 18 meters. Additional follow-up for up to 120 weeks suggested continued improvement in three participants and stabilization in the others. Two participants in the vestronidase alfa development program experienced marked improvement in pulmonary function. Overall, the results observed would not have been anticipated in the absence of treatment. The effect of vestronidase alfa on the central nervous system manifestations of MPS VII has not been determined.The FDA approved vestronidase alfa-vjbk based primarily on evidence from one clinical trial (NCT02230566) of 12 participants with mucopolysaccharidosis VII. The trial was conducted at four sites in the United States.The benefit and side effects of vestronidase alfa were based primarily on one trial. Participants were randomly assigned to four groups