Mepsevii® (vestronidase alfa—vjbk)

The first and only enzyme replacement therapy (ERT) for MPS VII.


Mepsevii is indicated in pediatric and adult patients for the treatment of Mucopolysaccharidosis VII (MPS VII, Sly syndrome). The effect of Mepsevii on the central nervous system manifestations of MPS VII has not been determined.


What is the most important information to know about Mepsevii?

  • A severe allergic reaction called anaphylaxis has occurred with Mepsevii treatment, as early as the first dose.
  • Symptoms of an allergic reaction will be monitored closely while receiving Mepsevii and for 60 minutes after the injection.
  • If anaphylaxis is experienced, the Mepsevii infusion will be immediately discontinued.

What are the possible side effects of Mepsevii?

  • The most common side effects of Mepsevii are:
    • Leakage of Mepsevii into the surrounding tissue during infusion
    • Diarrhea
    • Rash
    • Severe allergic reaction (anaphylaxis)
    • Infusion site swelling
    • Swelling around the infusion site
    • Severe itching of the skin
  • One patient experienced a seizure during a fever while taking Mepsevii.

Before receiving Mepsevii, doctors should be informed about all medical conditions, including if:

  • One is pregnant, thinks she may be pregnant, or plans to become pregnant. There is not enough experience to know if Mepsevii may harm an unborn baby.
  • One is breastfeeding or plans to breastfeed. There is not enough experience to know if Mepsevii passes into breast milk. Women should talk with their doctor about the best way to feed their babies while you receiving Mepsevii.

These are not all the possible side effects of Mepsevii. Doctors should be contacted for medical advice about side effects.

Side effects may be reported to the FDA at (800) FDA-1088 or Side effects may also be reported to Ultragenyx at 1-888-756-8657.

Full U.S. Prescribing Information for Mepsevii >

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