Vosoritide

Ensure adequate food and fluid intake prior to administration. ( 2.1 ) Recommended dosage is based on patient's actual body weight. Administer VOXZOGO subcutaneously once daily. ( 2.2 ) Reconstitute prior to use. Injection volume is based on both patient's weight and concentration of reconstituted VOXZOGO. ( 2.2 ) Monitor growth and adjust dosage according to actual body weight. Permanently discontinue upon closure of epiphyses. ( 2.3 ) See full prescribing information for reconstitution, dilution, and administration instructions. ( 2.4 )

2.1 Important Instructions Prior to Administration of VOXZOGO To reduce the risk of low blood pressure and its associated signs and symptoms, instruct the caregiver and patient that the patient should [see Warnings and Precautions (5.1) ] : Have adequate food intake prior to VOXZOGO administration. Drink approximately 240 to 300 mL of fluid in the hour prior to VOXZOGO administration.

2.2 Recommended Dosage and Administration The recommended dosage of VOXZOGO is based on the patient's actual body weight (see Table 1 ). VOXZOGO is administered by subcutaneous injection once daily [see Dosage and Administration (2.4) ] . Inject VOXZOGO at approximately the same time each day, if possible. The volume of VOXZOGO to be administered (injection volume) is based on the patient's actual body weight and the concentration of reconstituted VOXZOGO (0.8 mg/mL or 2 mg/mL) (see Table 1 ). VOXZOGO must be reconstituted prior to use [see Dosage and Administration (2.4) ] . Table 1: Recommended VOXZOGO Daily Dosage and Injection Volume Actual Body Weight Intermediate body weights that fall within these weight bands should be rounded to the nearest whole number. Dose Injection Volume Vial Strength for Reconstitution The concentration of vosoritide in reconstituted 0.4 mg vial and 0.56 mg vial is 0.8 mg/mL. The concentration of vosoritide in reconstituted 1.2 mg vial is 2 mg/mL. 3 kg 0.096 mg 0.12 mL 0.4 mg 4 kg 0.12 mg 0.15 mL 0.4 mg 5 kg 0.16 mg 0.2 mL 0.4 mg 6 to 7 kg 0.2 mg 0.25 mL 0.4 mg 8 to 11 kg 0.24 mg 0.3 mL 0.4 mg 12 to 16 kg 0.28 mg 0.35 mL 0.56 mg 17 to 21 kg 0.32 mg 0.4 mL 0.56 mg 22 to 32 kg 0.4 mg 0.5 mL 0.56 mg 33 to 43 kg 0.5 mg 0.25 mL 1.2 mg 44 to 59 kg 0.6 mg 0.3 mL 1.2 mg 60 to 89 kg 0.7 mg 0.35 mL 1.2 mg ≥ 90 kg 0.8 mg 0.4 mL 1.2 mg Missed dose If a dose of VOXZOGO is missed, it can be administered within 12 hours of the scheduled time of administration. Beyond 12 hours, skip the missed dose and administer the next daily dose according to the usual dosing schedule.

2.3 Growth Monitoring Monitor and assess patient body weight, growth, and physical development regularly every 3 to 6 months. Adjust the dosage according to the patient's actual body weight [see Dosage and Administration (2.2) ] . Permanently discontinue VOXZOGO upon confirmation of no further growth potential, indicated by closure of epiphyses.

2.4 Preparation and Administration Reconstitute VOXZOGO before administration using the provided diluent syringe containing Sterile Water for Injection, USP (see Reconstitution Instructions below). Caregivers may inject VOXZOGO subcutaneously after proper training by a healthcare professional on the preparation and administration of VOXZOGO [see Instructions for Use ]. Reconstitution Instructions Select the correct VOXZOGO vial strength (co-packaged with prefilled syringe with Sterile Water for Injection diluent) based on the patient's actual body weight [see Dosage and Administration (2.2) ] . Remove VOXZOGO vial and prefilled diluent syringe from the refrigerator and allow the vial and prefilled diluent syringe to reach room temperature before reconstituting VOXZOGO. Attach the diluent needle provided with ancillary supplies to the diluent prefilled syringe. Inject the entire diluent prefilled syringe volume into the vial (see Table 2 ). Gently swirl the diluent in the vial until the white powder is completely dissolved. Do not shake. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. Once reconstituted VOXZOGO is a clear, colorless to yellow liquid. The solution should not be used if discolored or cloudy, or if particles are present. The concentration of reconstituted solution is 0.8 mg/mL or 2.0 mg/mL (see Table 2 ). After reconstitution, VOXZOGO can be held in the vial at a room temperature 20°C to 25°C (68°F to 77°F) for a maximum of 3 hours. For administration, extract the required dose volume from the vial using the supplied administration syringe [see Dosage and Administration (2.2) ] . Table 2: Dilution Requirements for VOXZOGO Prior to Administration Vial Strength Reconstitution Volume Reconstituted Concentration 0.4 mg 0.5 mL 0.8 mg/mL 0.56 mg 0.7 mL 0.8 mg/mL 1.2 mg 0.6 mL 2 mg/mL 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. Instructions for Subcutaneous Administration See the Instructions for Use document for detailed, illustrated instructions. 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.

The following clinically significant adverse reactions are described elsewhere in the labeling: Risk of Low Blood Pressure [see Warnings and Precautions (5.1) ] Most common adverse reactions (>10%) are injection site erythema, injection site swelling, rash, vomiting, injection site urticaria, arthralgia, decreased blood pressure, and gastroenteritis. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact BioMarin Pharmaceutical Inc. at 1-866-906-6100, 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. Pediatric Patients 5 Years of Age and Older VOXZOGO was studied in a 52-week, randomized, double-blind, placebo-controlled trial in 121 subjects with achondroplasia (Study 1) [see Clinical Studies (14) ] . The subjects' ages ranged from 5.1 to 14.9 years with a mean of 8.7 years. Sixty four (53%) subjects were male and 57 (47%) were female. Overall, 86 (71%) subjects were White, 23 (19%) were Asian, 5 (4%) were Black or African American, and 7 (6%) were classified as "multiple" race. The demographic and baseline characteristics were balanced between treatment groups. The subjects received either VOXZOGO 15 mcg/kg, or placebo administered subcutaneously once daily. Table 3 shows adverse reactions that occurred in ≥5% of patients treated with VOXZOGO and at a percentage greater than placebo. Table 3: Adverse Reactions that Occurred in ≥5% of Patients Treated with VOXZOGO and at a Percentage Greater than Placebo in Study 1 Includes adverse reactions occurring more frequently in the vosoritide arm and with a risk difference of ≥5% (i.e., difference of >2 subjects) between treatment arms Adverse Reaction Placebo (N=61) n (%) VOXZOGO (N=60) n (%) Abbreviations: N, total number of subjects in the treatment arm; n, number of subjects with the adverse reaction; %, percent of subjects with the adverse reaction. Injection site erythema 42 (69%) 45 (75%) Injection site swelling 22 (36%) 37 (62%) Vomiting 12 (20%) 16 (27%) Injection site urticaria 6 (10%) 15 (25%) Arthralgia 4 (7%) 9 (15%) Decreased blood pressure 3 (5%) 8 (13%) Gastroenteritis Includes the preferred terms: gastroenteritis and gastroenteritis, viral 5 (8%) 8 (13%) Diarrhea 2 (3%) 6 (10%) Dizziness Includes the preferred terms: dizziness, presyncope, procedural dizziness, vertigo 2 (3%) 6 (10%) Ear pain 3 (5%) 6 (10%) Influenza 3 (5%) 6 (10%) Fatigue Includes the preferred terms: fatigue, lethargy, malaise 2 (3%) 5 (8%) Seasonal allergy 1 (2%) 4 (7%) Dry skin 0 3 (5%) Laboratory Abnormalities Increase in Alkaline Phosphatase More VOXZOGO-treated patients had an increase in alkaline phosphatase levels during the study compared to placebo (17% vs 7%). 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. Pediatric Patients <5 Years The safety of VOXZOGO in pediatric patients <5 years with achondroplasia was evaluated in a 52-week randomized, double blind, placebo-controlled study (Study 2) . In this study, 64 patients from 4.4 months to <5 years of age were randomized to receive either a daily vosoritide dose with similar exposure to that characterized to be safe and effective in children with ACH aged ≥5 years old, or placebo. An additional 11 patients received open-label treatment as part of this study. Subjects received 30 mcg/kg while they were <2 years of age. The daily dose for subjects was adjusted to 15 mcg/kg immediately following their 2 year birthday. The most common adverse reactions (>10%) reported in pediatric patients <5 years were injection site reactions (86%) and rash (28%). The overall safety profile of VOXZOGO in pediatric patients <5 years was similar to that seen in older pediatric patients.

6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of VOXZOGO. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Skin and Subcutaneous Tissue Disorders: hypertrichosis (includes the preferred terms: hair growth abnormal and hypertrichosis).

12.1 Mechanism of Action In patients with achondroplasia, endochondral bone growth is negatively regulated due to a gain of function mutation in fibroblast growth factor receptor 3 ( FGFR3 ). Binding of vosoritide to natriuretic peptide receptor-B (NPR-B) antagonizes FGFR3 downstream signaling by inhibiting the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the mitogen-activated protein kinase (MAPK) pathway at the level of rapidly accelerating fibrosarcoma serine/threonine protein kinase (RAF-1). As a result, vosoritide, like CNP, acts as a positive regulator of endochondral bone growth as it promotes chondrocyte proliferation and differentiation. In animal models with open growth plates, vosoritide administration resulted in the promotion of chondrocyte proliferation and differentiation that led to a widening of the growth plate and subsequent increase in skeletal growth. In the mouse models of FGFR3-related chondrodysplasia, a partial or complete normalization of the dwarfism phenotype was observed.

12.2 Pharmacodynamics 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.

12.3 Pharmacokinetics The area under the concentration-time curve (AUC) and peak concentration (C max ) of vosoritide increased greater than proportionally following subcutaneous administration to pediatric subjects with achondroplasia in the dose range of 7.5 to 30.0 mcg/kg. The pharmacokinetics of vosoritide were evaluated in 58 subjects aged 5 to 13 years with achondroplasia who received subcutaneous injections of vosoritide 15 mcg/kg once daily for 52 weeks. The mean (± SD) C max and area under the concentration-time curve from time zero to the last measurable concentration (AUC 0-t ) observed across 52 weeks of treatment ranged from 4.71 (± 2.32) to 7.18 (± 9.65) ng/mL, and 161 (± 98.1) to 290 (± 235) ng-min/mL, respectively. No drug accumulation was observed following 15 mcg/kg once daily dosing. The exposure of vosoritide increased with the duration of treatment. The mean AUC 0-t at week 52 increased approximately 20% compared to that at day 1. Absorption Absolute bioavailability for vosoritide following subcutaneous injection was not determined. Vosoritide was absorbed with a median T max 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. Specific Populations No clinically significant differences in the vosoritide pharmacokinetics were observed based on age (0.4 to 15 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 (5 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. Based on in vitro studies, vosoritide is considered unlikely to inhibit the human drug uptake or efflux transporters such as OAT1, OAT3, OCT1, OCT2, OATP1B1, OATP1B3, MATE1, MATE2-K, BCRP, P-gp, and BSEP at clinically relevant concentrations and therefore, no effect of vosoritide is anticipated on concomitantly administered drugs that are substrates of these transporters. In vivo assessment of drug-drug interactions No clinical studies evaluating the drug-drug interaction potential of vosoritide have been conducted.

12.6 Immunogenicity The observed incidence of anti-drug antibodies is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of vosoritide. Of 131 subjects aged 5 years and older who were treated with VOXZOGO 15 mcg/kg/day and evaluable for the presence of anti-drug antibodies (ADA) for up to 240 weeks, ADA were detected in 35% (46/131). The earliest time to ADA development was day 85. All ADA-positive subjects tested negative for anti-vosoritide neutralizing antibodies. There was no correlation between the number, duration, or severity of hypersensitivity adverse reactions or injection site reactions and ADA positivity or mean ADA titer. There was no association between ADA positivity or mean ADA titer and change from baseline in annual growth velocity (AGV) or height Z-score at month 12. There was no impact of serum ADA detected on the plasma PK measurements of vosoritide. In subjects under 5 years of age, 33% (20/61) of vosoritide-treated subjects tested positive for ADA and all placebo-treated subjects tested negative for ADA for up to 44 months. The earliest time to ADA development was week 26. All of the ADA-positive subjects tested negative for neutralizing antibodies at all time points. There was no impact of ADA development on safety, efficacy or PK of vosoritide up to Month 12.