Discard any unused portion. Do not pool unused portions from the vials. Do not administer more than 1 dose from a vial. Do not mix with other medications.
- Ensure patients have had adequate food and fluid intake prior to VOXZOGO administration [see Dosage and Administration (2.1)]. Slowly withdraw the dosing volume of the reconstituted VOXZOGO solution from the single-dose vial into a syringe.
- Rotate sites for subcutaneous injections.
- The recommended injection sites for VOXZOGO are: the front middle of the thighs, the lower part of the abdomen at least 2 inches (5 centimeters) away from the navel, top of the buttocks or the back of the upper arms. The same injection area should not be used on two consecutive days. Do not inject VOXZOGO into sites that are red, swollen, or tender.
Discussion of Selected Adverse Reactions
Decreased blood pressure
Eight (13%) of 60 subjects treated with VOXZOGO had a total of 11 events of transient decrease in blood pressure compared to 3 (5%) of 61 subjects on placebo, identified predominantly during periods of frequent monitoring at clinical visits after dosing over a 52-week treatment period. The median time to onset from injection was 31 (18 to 120) minutes with resolution within 31 (5 to 90) minutes in VOXZOGO-treated subjects. Two out of 60 (3%) VOXZOGO-treated subjects each had one symptomatic episode of decreased blood pressure with vomiting and/or dizziness compared to 0 of 61 (0%) subjects on placebo.
Injection site reactions
Injection site reactions occurred in 51 (85%) subjects receiving VOXZOGO and 50 (82%) subjects receiving placebo over a 52 week period of treatment. Injection site reactions included the preferred terms injection site erythema, injection site reaction, injection site swelling, injection site urticaria, injection site pain, injection site bruising, injection site pruritus, injection site hemorrhage, injection site discoloration, and injection site induration. Over a 52 week period, 51 (85%) of 60 subjects receiving VOXZOGO experienced a total of 6983 events of injection site reactions, while 50 (82%) of 61 subjects receiving placebo experienced a total of 1776 events of injections site reactions, representing 120.4 events per person/year exposure and 29.2 per person/year exposure, respectively. One injection site reaction event could have been associated with one or more injection site reaction symptoms (e.g., injection site swelling, injection site erythema, injection site urticaria, etc.). Two subjects in the VOXZOGO arm discontinued treatment due to adverse reactions of pain and anxiety with injections.
Risk Summary
There are no available data on vosoritide use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, there was no evidence of embryo-fetal toxicity or congenital malformations when pregnant rats and rabbits were administered vosoritide subcutaneously at doses equivalent to 14-times and 200-times, respectively, the exposure at the maximum recommended human dose (MRHD) (see Data).
The estimated background risk of major birth defects for the indicated population is higher than the general population. The estimated background risk of 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 an embryofetal developmental toxicity study in rats, vosoritide was administered at 90, 270, 540 mcg/kg once daily by subcutaneous injection during the period of major organogenesis from gestation day (GD) 6 – 17. There were no effects on maternal animals or on embryofetal development at the highest dose administered (14-times the exposure at the MRHD).
In an embryofetal developmental toxicity study in rabbits, vosoritide was administered at 45, 135, 240 mcg/kg once daily by subcutaneous injection during the period of major organogenesis (GD 7 – 19). No effects were observed in maternal animals or on embryofetal development at the highest dose administered (200-times the exposure at the MRHD).
In a pre- and postnatal toxicity study in rats, vosoritide was administered at 90, 270, and 540 mcg/kg once daily by subcutaneous injection during the period of major organogenesis and continuing to weaning (GD 6 through postpartum day 20). There were no effects on maternal animals, including maintenance of pregnancy, parturition, or care of offspring, and no effects were noted on offspring growth and development or ability to reproduce at the highest dose (14-times the exposure at the MRHD).
Risk Summary
There is no information regarding the presence of vosoritide in human milk, the effects on the breastfed infant, or the effects on milk production. Vosoritide is present in rat milk. When a drug is present in animal milk, it is likely that the drug will be present in human milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VOXZOGO and any potential adverse effects on the breastfed child from VOXZOGO or from the underlying maternal condition.
NPR-B Binding Activity Biomarker and Bone Metabolism Biomarker
An increase in urinary cyclic guanosine monophosphate (cGMP) concentrations from pre-dose baseline were observed within the first four hours post-dose, with a maximum level at 2 hours post-dose, after VOXZOGO administration to pediatric patients with achondroplasia.
Daily administration of VOXZOGO also led to the increase from baseline in serum collagen type X marker (CXM), an endochondral ossification biomarker and remains elevated beyond 24 months. In subjects aged 5 - 14 years old at screening, exposure-response analyses showed that vosoritide activity measured by urinary cGMP was near saturation at the dose of 15 mcg/kg once daily, while maximal increase in growth plate activity indicated by CXM was achieved at this dose.
Cardiac Electrophysiology
At the maximum approved recommended dose, Voxzogo does not prolong the QT interval to any clinically relevant extent.
Absorption
Absolute bioavailability for vosoritide following subcutaneous injection was not determined. Vosoritide was absorbed with a median Tmax of 15 minutes after dosing.
Distribution
The mean (± SD) apparent volume of distribution of vosoritide across 52 weeks of subcutaneous administration of VOXZOGO 15 mcg/kg once daily ranged from 2880 (± 2450) to 3020 (± 1980) mL/kg.
Elimination
The mean (± SD) apparent clearance of vosoritide across 52 weeks of subcutaneous administration of VOXZOGO 15 mcg/kg once daily ranged from 79.4 (± 53.0) to 104 (± 98.8) mL/min/kg. The mean (± SD) half-life ranged from 21.0 (± 4.7) to 27.9 (± 9.9) minutes.
Metabolism
The metabolism of vosoritide is expected to occur via catabolic pathways with degradation into small peptide fragments and amino acids.
Special Populations
No clinically significant differences in the vosoritide pharmacokinetics were observed based on age (0.9 to 16 years), sex or race. The effect of hepatic or renal impairment on the pharmacokinetics of vosoritide is unknown.
Body weight
Population pharmacokinetic analyses indicated that body weight is a significant covariate for vosoritide clearance and volume of distribution. The apparent clearance and volume of distribution of vosoritide increased with increasing body weight in patients with achondroplasia (9 to 74.5 kg).
Drug Interaction Studies
In vitro assessment of drug-drug interactions
In vitro studies showed that vosoritide, at therapeutic concentrations, does not inhibit or induce Cytochrome P450 enzymes.
In vivo assessment of drug-drug interactions
No clinical studies evaluating the drug-drug interaction potential of vosoritide have been conducted.
In a fertility and reproductive study in male and female rats at doses up to 540 mcg/kg/day (15-times the exposure at the MRHD), vosoritide had no effect on mating performance, fertility, or litter characteristics.
Height Standard Deviation Score (SDS)
The LS mean change from baseline to Week 52 in height SDS was -0.02 in the placebo group and 0.26 in the VOXZOGO group. The difference in LS mean change from baseline was 0.28 (95% CI 0.17, 0.39; p<0.0001) in favor of VOXZOGO. The LS mean change from baseline to Week 52 in upper to lower body segment ratio was -0.02 in the placebo group and -0.03 in the VOXZOGO group. The difference in LS mean change from baseline was -0.01 (95% CI -0.05, 0.02; p=0.5).
Open-label extension
After the 52 week double blind, placebo-controlled, phase 3 study, Study 1, 58 subjects initially randomized to VOXZOGO enrolled into an open-label extension. Among the subjects who had 2 years of follow-up since randomization, the improvement in AGV was maintained.
How Supplied
VOXZOGO for injection is a white to yellow lyophilized powder for reconstitution and is provided as a co-pack which includes ten:
- Sterile, single-dose 2 mL glass vials containing VOXZOGO
- Diluent (Sterile Water for Injection, USP) in a single-dose prefilled syringe
- Diluent transfer needles (23 gauge)
- Single-dose administration syringes (30 gauge) both with needle retraction safety devices
| Strength (mg) | Diluent (mL) | Co-pack NDC Number | Flip Cap Color |
|---|
| 0.4 | 0.5 | NDC 68135-082-36 | White |
| 0.56 | 0.7 | NDC 68135-119-66 | Magenta |
| 1.2 | 0.6 | NDC 68135-181-93 | Grey |
The following items to be obtained separately; alcohol aseptic wipes, gauze, bandages and sharps container.
Handling
Reconstituted VOXZOGO must be administered within 3 hours of reconstitution [see Dosage and Administration (2.4)].
Preparation and Administration
Instruct caregivers on proper preparation and administration of VOXZOGO. Ensure caregivers have demonstrated the ability to perform a subcutaneous injection [see Dosage and Administration (2.4)].
Instruct caregivers in the technique of proper syringe and needle disposal, and advise them not to reuse these items. Instruct caregivers to dispose needles and syringes in a puncture-resistant container.
Risk of Low Blood Pressure
Inform caregivers and patients that VOXZOGO may lower blood pressure after administration. Instruct caregivers and patients that prior to VOXZOGO administration, the patient should have adequate food intake and within the hour prior to administration, the patient should drink approximately 8-10 ounces (240-300 mL) of fluid [see Dosage and Administration (2.1) and Warnings and Precautions (5.1)].
Manufactured for:
BioMarin Pharmaceutical Inc.
105 Digital Drive, Novato, CA 94949