Elosulfase alfa

12.1 Mechanism of Action Mucopolysaccharidoses comprise a group of lysosomal storage disorders caused by the deficiency of specific lysosomal enzymes required for the catabolism of glycosaminoglycans (GAG). Mucopolysaccharidosis IVA (MPS IVA, Morquio A Syndrome) is characterized by the absence or marked reduction in N -acetylgalactosamine-6-sulfatase activity. The sulfatase activity deficiency results in the accumulation of the GAG substrates, KS and C6S, in the lysosomal compartment of cells throughout the body. The accumulation leads to widespread cellular, tissue, and organ dysfunction. VIMIZIM is intended to provide the exogenous enzyme N-acetylgalactosamine-6-sulfatase that will be taken up into the lysosomes and increase the catabolism of the GAGs KS and C6S. Elosulfase alfa uptake by cells into lysosomes is mediated by the binding of mannose-6-phosphate-terminated oligosaccharide chains of elosulfase alfa to mannose-6-phosphate receptors. In the absence of an animal disease model that recapitulates the human disease phenotype, elosulfase alfa pharmacological activity was evaluated using human primary chondrocytes from two MPS IVA patients. Treatment of MPS IVA chondrocytes with elosulfase alfa induced clearance of KS lysosomal storage from the chondrocytes.

1 INDICATIONS AND USAGE VIMIZIM (elosulfase alfa) is indicated for patients with Mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome). VIMIZIM is a hydrolytic lysosomal glycosaminoglycan (GAG)-specific enzyme indicated for patients with Mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome). ( 1 )

2 DOSAGE AND ADMINISTRATION Administration of VIMIZIM should be supervised by a healthcare provider knowledgeable in the management of hypersensitivity reactions including anaphylaxis. ( 2.1 ) 2 mg per kg body weight administered once every week as an intravenous infusion over a minimum of 3.5 to 4.5 hours, based on infusion volume. ( 2.2 , 2.4 ) See the full prescribing information for administration modifications due to hypersensitivity reactions. ( 2.3 ) 2.1 Important Administration Instructions Administration of VIMIZIM should be supervised by a healthcare provider knowledgeable in the management of hypersensitivity reactions including anaphylaxis [see Warnings and Precautions (5.1) ] . Initiate VIMIZIM in a healthcare setting with appropriate medical monitoring and support measures, including access to cardiopulmonary resuscitation [see Warnings and Precautions (5.1) ] . This product must be diluted prior to administration and administered using a low-protein binding infusion set equipped with a low-protein binding 0.2 micrometer (µm) in-line filter. Consider pre-medicating with antihistamines, with or without antipyretics, 30 to 60 minutes prior to the start of the infusion [see Warnings and Precautions (5.1) ] . 2.2 Recommended Dosage The recommended dosage of VIMIZIM is 2 mg/kg administered intravenously over a minimum range of 3.5 to 4.5 hours (based on infusion volume) once every week. 2.3 Administration Modifications Due to Hypersensitivity Reaction In the event of a severe hypersensitivity reaction (e.g., anaphylaxis), discontinue the VIMIZIM infusion and immediately initiate appropriate medical treatment, including use of epinephrine. In the event of a mild to moderate hypersensitivity reaction, consider slowing or temporarily interrupting the infusion, or administering additional antihistamines, antipyretics, and/or corticosteroids [see Warnings and Precautions (5.1) ] . 2.4 Preparation Instructions Use aseptic technique during preparation. Determine the number of VIMIZIM vials based on the patient's actual body weight in kg and the recommended dose [see Dosage and Administration (2.2) ] . Remove vials from the refrigerator. Select the appropriate size 0.9% Sodium Chloride Injection, USP infusion bag and calculate the infusion volume based on patient's actual body weight: For patients who weigh less than 25 kg, the final infusion volume should be 100 mL For patients who weigh 25 kg or more, the final infusion volume should be 250 mL. Withdraw and discard a volume of 0.9% Sodium Chloride Injection, USP from either the 100 mL or 250 mL infusion bag equal to the volume of VIMIZIM to be added. Withdraw the required volume of VIMIZIM from the vial(s) and add to the 0.9% Sodium Chloride Injection, USP infusion bag. Gently rotate the infusion bag to mix the diluted solution. Avoid vigorous shaking or agitation. Discard unused portion remaining in the vial(s). Visually inspect the solution for particulate matter and discoloration. The solution should be clear to slightly opalescent and colorless to pale yellow. The diluted VIMIZIM solution may contain proteinaceous particles in the form of translucent fibers which will be removed by the in-line filter during infusion. Discard if opaque particles are present or the solution is discolored. 2.5 Administration Instructions Use an infusion set equipped with a low-protein binding 0.2 micrometer (µm) in-line filter to administer VIMIZIM . Do not infuse with other products in the infusion tubing. Compatibility with other products has not been evaluated. Table 1. Intravenous Infusion Rate for VIMIZIM Based on Patient Weight Patient Weight (kg) Infusion rate (mL/hour) Initial Rate (first 15 minutes) Subsequent Rate (next 15 minutes) Subsequent Rate Increments If tolerated, the infusion rate can be increased incrementally up to the maximum infusion rate. Maximum Infusion Rate Less than 25 kg 3 mL/hour 6 mL/hour 6 mL/hour every 15 minutes 36 mL/hour 25 kg or more 6 mL/hour 12 mL/hour 12 mL/hour every 15 minutes 72 mL/hour Table 2. Minimum Infusion Time for VIMIZIM Based on Patient Weight Patient Weight (kg) Minimum Infusion Time (hours) Less than 25 kg 3.5 hours 25 kg or more 4.5 hours 2.6 Storage of the Diluted Solution If the diluted VIMIZIM solution is not used immediately: Store the diluted solution refrigerated at 2°C to 8°C (36°F to 46°F) for up to 24 hours or at room temperature between 23°C to 27°C (73°F to 81°F) for up to 24 hours. Diluted VIMIZIM solution must be used within 48 hours, inclusive of total infusion time. Discard if not used within 48 hours. Do not freeze or shake.

6 ADVERSE REACTIONS The following serious adverse reactions are described below and elsewhere in the labeling: Hypersensitivity Reactions Including Anaphylaxis [see Warnings and Precautions (5.1) ] . Risk of Acute Respiratory Complications [see Warnings and Precautions (5.2) ] . Spinal or Cervical Cord Compression [see Warnings and Precautions (5.3) ] . Most common adverse reactions (≥10%) are: pyrexia, vomiting, headache, nausea, abdominal pain, chills, and fatigue. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact BioMarin 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. A 24-week, randomized, double-blind, placebo-controlled clinical trial of VIMIZIM was conducted in 176 patients with MPS IVA, ages 5 to 57 years old. Approximately half of the patients (49%) were male. Of the 176 patients, 65% were White, 23% Asian, 3% Black, and 10% Other race. The majority of patients (78%) were non-Hispanic. Patients were randomized to three treatment groups: VIMIZIM 2 mg/kg once per week (n=58), VIMIZIM 2 mg/kg once every other week (n=59), or placebo (n=59). All patients were treated with antihistamines prior to each infusion. Table 3 summarizes the most common adverse reactions that occurred in the placebo-controlled trial with an incidence of ≥ 10% in patients treated with VIMIZIM 2 mg/kg once per week and with a higher incidence than in the placebo-treated patients. Table 3: Adverse Reactions That Occurred in the Placebo-Controlled Trial in At Least 10% of Patients in the VIMIZIM 2 mg/kg Once Per Week Group and with a Higher Incidence than in the Placebo Group Adverse Reaction VIMIZIM 2 mg/kg once per week Placebo N= 58 n (%) N= 59 n (%) Pyrexia 19 (33%) 8 (14%) Vomiting 18 (31%) 4 (7%) Headache 15 (26%) 9 (15%) Nausea 14 (24%) 4 (7%) Abdominal pain 12 (21%) 1 (2%) Chills 6 (10%) 1 (2%) Fatigue 6 (10%) 2 (3%) Extension Trial An open-label extension trial was conducted in 173 patients who completed the placebo-controlled trial [see Clinical Studies (14) ] . No new adverse reactions were reported. 6.2 Immunogenicity As with all therapeutic proteins, including VIMIZIM, there is potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies in other studies or to other elosulfase alfa products may be misleading. All patients treated with VIMIZIM 2 mg/kg once per week in the placebo-controlled trial developed anti-drug antibodies by Week 4. Anti-drug antibody titers were sustained or increased for the duration of VIMIZIM treatment. Because all patients developed anti-drug antibodies, associations between antibody titers and reductions in treatment effect or the occurrence of anaphylaxis or other hypersensitivity reactions could not be determined. All patients treated with VIMIZIM 2 mg/kg once per week tested positive for neutralizing antibodies capable of inhibiting the drug from binding to the mannose-6-phosphate receptor at least once during the trial. Binding to this receptor is required for VIMIZIM to be taken into cells where it is active. Neutralizing antibody titers were not determined in the patients. Therefore, the possibility of an association between neutralizing antibody titer and treatment effect cannot be assessed.