Vestronidase Alfa

Mucopolysaccharidosis VII (MPS VII or Sly syndrome) is a lysosomal disorder characterized by the deficiency of GUS that results in GAG accumulation in cells throughout the body leading to multisystem tissue and organ damage. Vestronidase alfa-vjbk is a recombinant form of human GUS and is intended to provide exogenous GUS enzyme for uptake into cellular lysosomes.

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

• None.contraindicated

The recommended dosage is 4 mg/kg administered every two weeks as an intravenous infusion. ( 2.1 ) Premedication with a non-sedating antihistamine with or without an anti-pyretic is recommended 30 to 60 minutes prior to the start of the infusion. ( 2.2 , 5.1 ) Administer the infusion over approximately 4 hours. In the first hour of infusion, infuse 2.5% of the total volume. After the first hour, the rate can be increased to infuse the remainder of the volume over 3 hours as tolerated. See Table 1 in the full prescribing information for the rate of infusion by dose and body weight. ( 2.4 ) For additional information on preparation, administration, and storage see the full prescribing information. ( 2.3 , 2.4 ) 2.1 Recommended Dosage MEPSEVII should be administered under the supervision of a healthcare professional with the capability to manage anaphylaxis. Premedication is recommended 30 to 60 minutes prior to the start of the infusion [see Dosage and Administration ( 2.2 )]. The recommended dosage of MEPSEVII is 4 mg/kg administered by intravenous infusion every two weeks. Administer the infusion over approximately 4 hours. Infuse the first 2.5% of the total volume over the first hour. After the first hour, increase the infusion rate as tolerated in order to complete infusion over the following 3 hours according to the recommended rate guidelines in Table 1 [see Dosage and Administration ( 2.4 )].

5.1 Anaphylaxis Anaphylaxis to MEPSEVII was reported in 2 of 20 patients in the clinical program [see Adverse Reactions ( 6.1 )] . These reactions occurred during MEPSEVII infusion and were observed as early as the first dose of MEPSEVII for one patient. Manifestations included respiratory distress, cyanosis, decreased oxygen saturation, and hypotension. The two patients with anaphylaxis to MEPSEVII during the clinical trials had one occurrence each and tolerated subsequent infusions of MEPSEVII, without recurrence. Anaphylaxis can be life-threatening. MEPSEVII should be administered under the supervision of a healthcare professional with the capability to manage anaphylaxis. Patients should be observed for 60 minutes after MEPSEVII administration. If severe systemic reactions occur, including anaphylaxis, immediately discontinue the MEPSEVII infusion and provide appropriate medical treatment. Prior to discharge, inform patients of the signs and symptoms of anaphylaxis and instruct them to seek immediate medical care if symptoms occur. Consider the risks and benefits of re-administering MEPSEVII following anaphylaxis.

The following serious adverse reactions are described below and elsewhere in the labeling: Anaphylaxis [see Warnings and Precautions ( 5.1 )] Most common adverse reactions (≥1 patient) are: Infusion site extravasation, diarrhea, rash, anaphylaxis, infusion site swelling, peripheral swelling and pruritus. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ultragenyx at 1-888-756-8657 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The MEPSEVII clinical program included 23 patients aged 5 months to 25 years who received treatment with MEPSEVII at doses up to 4 mg/kg once every two weeks for up to 187 weeks. Nineteen patients were younger than 18 years of age. Table 2 summarizes the adverse reactions that occurred in Study 301, a randomized start trial in 12 patients with MPS VII between the ages of 8 and 25 years [see Clinical Studies ( 14 )] . Adverse reactions in Table 2 occurred in one or more patients treated with MEPSEVII at a dosage of 4 mg/kg at a higher patient frequency than placebo. Adverse reaction incidence rates are presented in the table below to account for the different duration of exposure to active treatment vs. placebo. Table 2.

8.1 Pregnancy Risk Summary There are no available data on MEPSEVII use in pregnant women to determine a drug-associated risk of adverse developmental outcomes. In embryofetal development studies, vestronidase alfa-vjbk administered intravenously to pregnant rats and rabbits during the period of organogenesis showed no adverse developmental outcomes at doses up to 1.6 and 10 times, respectively for rats and rabbits, the exposure at the recommended human dose. In a pre- and post-natal development study in rats, an increased number of stillbirths were observed at exposures less than the recommended human dose (see Data). The clinical relevance of these animal findings is uncertain. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data In embryofetal development studies, vestronidase alfa-vjbk administered intravenously to pregnant rats (once a week) and rabbits (once every 3 days) during the period of organogenesis showed no adverse developmental outcomes at doses up to 20 mg/kg.

Metabolism

The pharmacokinetics of vestronidase alfa-vjbk were evaluated in a total of 23 MPS VII patients including 19 pediatric patients and 4 adults. Serum exposures of vestronidase alfa-vjbk appeared to increase approximately proportionally from 1 mg/kg (0.25 times the approved recommended dosage) to 2 mg/kg (0.5 times the approved recommended dosage), and 4 mg/kg (the recommended dosage).

• Nov 15, 2017BLABLA761047Ultragenyx Pharm Inc

1. 1Product Dose Omission Issue58.1%
2. 2Cough46.5%
3. 3Rash46.5%
4. 4Vomiting46.5%
5. 5Fall34.8%
6. 6Pneumonia34.8%
7. 7Respiratory Failure34.8%
8. 8Acute Respiratory Failure23.2%
9. 9Anaphylactic Reaction23.2%
10. 10Contusion23.2%
11. 11Head Injury23.2%
12. 12Infusion Related Reaction23.2%
13. 13Nasopharyngitis23.2%
14. 14Pulmonary Embolism23.2%
15. 15Pyrexia23.2%

The 8 most recently updated of 8 ClinicalTrials.gov registrations naming Vestronidase Alfa as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Mucopolysaccharidosis VII Disease Monitoring Program
  Recruiting · Observational · 50 enrolled · Ultragenyx Pharmaceutical Inc
  NCT03604835updated 2026-06-11
• Expanded Access to Mepsevii
  Available · Expanded access · Ultragenyx Pharmaceutical Inc
  NCT03775174updated 2026-04-07
• PEARL (PrEnAtal Enzyme Replacement Therapy for Lysosomal Storage Disorders)
  Recruiting · Phase 1 · Interventional · 10 enrolled · University of California, San Francisco
  NCT04532047updated 2026-03-17
• A Phase 3 Study of UX003 Recombinant Human Betaglucuronidase (rhGUS) Enzyme Replacement Therapy in Patients With Mucopolysaccharidosis Type 7 (MPS 7)
  Completed · Phase 3 · Interventional · 12 enrolled · Ultragenyx Pharmaceutical Inc
  NCT02230566updated 2020-07-30
• A Study of UX003 Recombinant Human Beta-Glucuronidase (rhGUS) Enzyme Replacement Therapy in Subjects With Mucopolysaccharidosis Type 7, Sly Syndrome (MPS 7)
  Completed · Phase 3 · Interventional · 12 enrolled · Ultragenyx Pharmaceutical Inc
  NCT02432144updated 2020-07-30
• Study of UX003 Recombinant Human Beta-Glucuronidase (rhGUS) Enzyme Replacement Treatment in Mucopolysaccharidosis Type 7, Sly Syndrome (MPS 7) Patients Less Than 5 Years of Age
  Completed · Phase 2 · Interventional · 8 enrolled · Ultragenyx Pharmaceutical Inc
  NCT02418455updated 2019-10-30
• An Open-Label Phase 1/2 Study to Assess the Safety, Efficacy and Dose of Study Drug UX003 Recombinant Human Beta-glucuronidase (rhGUS) Enzyme Replacement Therapy in Patients With Mucopolysaccharidosis Type 7 (MPS 7)
  Completed · Phase 1 · Phase 2 · Interventional · 3 enrolled · Ultragenyx Pharmaceutical Inc
  NCT01856218updated 2019-01-04
• An Open-Label Treatment Protocol With UX003 rhGUS Enzyme Replacement Therapy for an Advanced Stage MPS 7 Patient
  No longer available · Expanded access · Joyce Fox
  NCT02097251updated 2017-02-06

Frequently asked questions

How does Vestronidase Alfa work?

Mucopolysaccharidosis VII (MPS VII or Sly syndrome) is a lysosomal disorder characterized by the deficiency of GUS that results in GAG accumulation in cells throughout the body leading to multisystem tissue and organ damage. Vestronidase alfa-vjbk is a recombinant form of human GUS and is intended to provide exogenous GUS enzyme for uptake into cellular lysosomes.

What is Vestronidase Alfa used for?

According to FDA labeling, Vestronidase Alfa carries indications including: MEPSEVII is indicated in pediatric and adult patients for the treatment of Mucopolysaccharidosis VII (MPS VII, Sly syndrome). Limitations of Use The effect of MEPSEVII on the central nervous system manifestations of MPS VII has not been determined.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Vestronidase Alfa?

Vestronidase Alfa is classified as Enzymes, Lysosomal beta Glucuronidase.

What are the brand names for Vestronidase Alfa?

Vestronidase Alfa is marketed under brand names including Mepsevii.

What are the contraindications for Vestronidase Alfa?

Vestronidase Alfa labeling lists contraindications including: None.. Always consult the full prescribing information and a clinician.