Vestronidase alfa-vjbk (trade name Mepsevii) is a drug for the treatment of Sly syndrome. It is a recombinant form of the human enzyme beta-glucuronidase. In the United States, it was approved in November 2017. Vestronidase alfa-vjbk (trade name Mepsevii) is a drug for the treatment of Sly syndrome. It is a recombinant form of the human enzyme beta-glucuronidase. In the United States, it was approved in November 2017.