Vestronidase alfa

Mucopolysaccharidosis VII (MEPSEVII, vestronidase alfa-vjbk). Should be administered under the supervision of a healthcare professional with the capability to manage anaphylaxis. Premedication with a non-sedating antihistamine, with or without an antipyretic, is recommended 30 to 60 minutes prior to the start of the infusion. Administration: infuse over approximately 4 hours — infuse the first 2.5% of the total volume over the FIRST HOUR, then increase the rate as tolerated to complete the remaining volume over the following 3 hours, following the label's Table 1 rate schedule by patient weight. Account for dead space in the lines so that 2.5% of the total infusion volume is actually delivered during the first hour. Use an infusion set with an in-line, low-protein-binding 0.2 micron filter; do not flush the line containing the drug (avoids a rapid bolus of infused enzyme); do not infuse with other products in the tubing. Additional saline may be given through a separate line (piggyback or Y-tube) to maintain flow because of the low infusion rate. Preparation: total dose (mg) = weight (kg) x 4 mg/kg; total vials = total dose divided by 10 mg/vial (round up); volume (mL) = total dose divided by the 2 mg/mL concentration; final solution is a 1:1 dilution with 0.9% sodium chloride injection (greater dilution may be used if the patient tolerates the additional volume, considering cardiac function and fluid status). Observe patients during and for a minimum of 60 minutes after the infusion for anaphylaxis; discontinue immediately for severe systemic reactions. Geriatric: clinical trials did not include any patients aged 65 and over. Source: US FDA prescribing information (DailyMed, Ultragenyx, label date 2025-11-18); NO UK SPC was available in the fetched bundle — verify against UK/EMA labelling before use.

The US label states a single weight-based dosage of 4 mg/kg every two weeks for all patients; safety and effectiveness have been established in paediatric patients less than 18 years of age. The clinical programme included 23 patients aged 5 months to 25 years treated at doses up to 4 mg/kg once every two weeks for up to 187 weeks, of whom 19 were younger than 18 years. Infusion rate is weight-banded (label Table 1) — e.g. for 3.5–5.9 kg, total volume 20 mL infused at 0.5 mL/h for the first hour then 6.5 mL/h for the subsequent 3 hours; consult the full Table 1 for the patient's weight band. Verify all paediatric dosing against a children's formulary and against UK labelling — this figure is from US prescribing information only.