Laronidase

12.1 Mechanism of Action Mucopolysaccharide storage disorders are caused by the deficiency of specific lysosomal enzymes required for the catabolism of glycosaminoglycans (GAG). Mucopolysaccharidosis I (MPS I) is characterized by the deficiency of α-L-iduronidase, a lysosomal hydrolase which catalyzes the hydrolysis of terminal α-L-iduronic acid residues of dermatan sulfate and heparan sulfate. Reduced or absent α-L-iduronidase activity results in the accumulation of the GAG substrates, dermatan sulfate and heparan sulfate, throughout the body and leads to widespread cellular, tissue, and organ dysfunction. The rationale of ALDURAZYME therapy in MPS I is to provide exogenous enzyme for uptake into lysosomes and increase the catabolism of GAG. ALDURAZYME uptake by cells into lysosomes is most likely mediated by the mannose-6-phosphate-terminated oligosaccharide chains of laronidase binding to specific mannose-6-phosphate receptors. Because many proteins in the blood are restricted from entry into the central nervous system (CNS) by the blood brain barrier, effects of intravenously administered ALDURAZYME on cells within the CNS cannot be inferred from activity in sites outside the CNS. The ability of ALDURAZYME to cross the blood brain barrier has not been evaluated in animal models or in clinical studies.

1 INDICATIONS AND USAGE ALDURAZYME ® is indicated for the treatment of: adult and pediatric patients with Hurler and Hurler-Scheie forms of Mucopolysaccharidosis I (MPS I) and patients with the Scheie form of MPS I who have moderate to severe symptoms. ALDURAZYME is a hydrolytic lysosomal glycosaminoglycan (GAG)-specific enzyme indicated for the treatment of adult and pediatric patients with Hurler and Hurler-Scheie forms of Mucopolysaccharidosis I (MPS I) and for the treatment of patients with the Scheie form of MPS I who have moderate to severe symptoms. ( 1 ) Limitations of Use: The risks and benefits of treating mildly affected patients with the Scheie form have not been established. ( 1 ) ALDURAZYME has not been evaluated for effects on the central nervous system manifestations of the disorder. ( 1 ) Limitations of Use The safety and effectiveness of treating mildly affected patients with the Scheie form have not been established. The effect of ALDURAZYME on central nervous system manifestations of the disorder has not been determined.

2 DOSAGE AND ADMINISTRATION For pretreatment recommendations, see Full Prescribing Information. ( 2.1 ) The recommended dosage is 0.58 mg/kg administered once weekly as an intravenous infusion. ( 2.2 ) For dosage and administration modifications due to hypersensitivity reactions or infusion-associated reactions (IARs), see Full Prescribing Information. ( 2.3 ) For instructions on preparation, storage, and administration, see Full Prescribing Information. ( 2.4 , 2.5 , 2.6 ) 2.1 Recommendations Prior to ALDURAZYME Treatment Premedication Prior to ALDURAZYME administration, consider premedicating with antihistamines, with or without antipyretics, 60 minutes before the start of infusion [see Warnings and Precautions (5.1 , 5.4) ]. Medical Support Appropriate medical monitoring and support measures, including cardiopulmonary resuscitation equipment, should be readily available during ALDURAZYME administration. 2.2 Recommended Dosage and Administration The recommended dosage of ALDURAZYME is 0.58 mg/kg (actual body weight) administered once weekly as an intravenous infusion. ALDURAZYME injection must be diluted with 0.9% Sodium Chloride Injection to a final volume of 50 mL, 100 mL or 250 mL as determined by the patient's body weight and cardiopulmonary condition: Patients with a body weight equal to or greater than 2 kg and less than 4 kg should receive a total volume of 50 mL; patients with a body weight equal to or greater than 4 kg and up to 20 kg should receive a total volume of 100 mL; and those patients with a body weight greater than 20 kg should receive a total volume of 250 mL [see Dosage and Administration (2.6) ]. For patients with underlying cardiac or respiratory compromise and weighing up to 30 kg, physicians may consider diluting ALDURAZYME in a volume of 100 mL and administering at a decreased infusion rate [see Dosage and Administration (2.6) ]. The initial infusion rate of ALDURAZYME is 10 mcg/kg/hr and may be increased every 15 minutes during the first hour, as tolerated, to a maximum infusion rate of 200 mcg/kg/hr. The maximum rate is then maintained for the remainder of the infusion (2 to 3 hours) [see Dosage and Administration (2.6) , Warnings and Precautions (5.2 , 5.3) ] . If one or more doses are missed, restart ALDURAZYME treatment as soon as possible and maintain the 1-week interval between infusions thereafter. Do not double a dose to compensate for a missed dose. 2.3 Administration Modifications due to Hypersensitivity or Infusion Associated Reaction In the event of a severe hypersensitivity reaction (e.g. anaphylaxis) or severe infusion-associated reaction (IAR), immediately discontinue ALDURAZYME administration and initiate appropriate medical treatment. For additional recommendations in the event of a severe hypersensitivity reaction, [ see Warnings and Precautions (5.1) ]. In the event of a mild to moderate hypersensitivity reaction or a mild to moderate IAR, consider temporarily holding the infusion for 15 to 30 minutes, or slowing the infusion rate by 25% to 50% [ see Dosage and Administration (2.6) ] , and initiating appropriate medical treatment [see Warnings and Precautions (5.1 , 5.4) ] . If symptoms persist despite holding or slowing the infusion, stop the infusion and monitor the patient. Consider re-initiating the infusion within 7 to 14 days using the incremental rate steps table [see Dosage and Administration (2.6) ] , up to 25% or 50% of the rate at which the reaction occurred with appropriate premedication. If symptoms subside after holding the infusion, resume infusion at a 25% to 50% reduced rate as tolerated. Alternatively, if symptoms subside after slowing the infusion, complete infusion at the reduced rate as tolerated. Starting with next infusion, increase the infusion rate by increments of 25% as tolerated until the recommended infusion rate is reached. Closely monitor the patient. 2.4 Preparation Instructions Prepare ALDURAZYME using low-protein-binding containers. There is no information on the compatibility of diluted ALDURAZYME with glass containers. Dilute ALDURAZYME in the following manner using aseptic technique: Determine the infusion bag volume and number of ALDURAZYME vials to be diluted based on actual body weight in kg and the recommended dose [see Dosage and Administration (2.2) ] . Round the number of vials up to the next whole number. Remove the appropriate number of ALDURAZYME vials from the refrigerator and allow the vials to reach room temperature 20°C to 25°C (68°F to 77°F) before use. Do not heat or microwave the vials. Visually inspect the solution in each vial for particulate matter and discoloration. The ALDURAZYME solution should be clear to slightly opalescent and colorless to pale yellow. Some translucency may be present in the solution. Discard if the solution is discolored or if visible particulate matter is present. Withdraw and discard a volume of the 0.9% Sodium Chloride Injection from an infusion bag, equal to the volume of ALDU

6 ADVERSE REACTIONS Serious and or clinically significant adverse reactions described elsewhere in labeling include: Hypersensitivity Reactions Including Anaphylaxis [see Warnings and Precautions (5.1) ] Acute Respiratory Complications Associated with Administration [see Warnings and Precautions (5.2) ] Acute Cardiorespiratory Failure [see Warnings and Precautions (5.3) ] Infusion-Associated Reactions [see Warnings and Precautions (5.4) ] Most common adverse reactions (≥10%) in patients: 6 months of age and older are: infusion reactions (pyrexia, chills, blood pressure increased, tachycardia, and oxygen saturation decreased). ( 6.1 ) 6 years and older are: rash, upper respiratory tract infection, injection site reaction, hyperreflexia, paresthesia, flushing, and poor venous access. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Genzyme at 1-800-745-4447 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 clinical practice. Serious adverse reactions reported with ALDURAZYME treatment during clinical trials were anaphylactic and hypersensitivity reactions. The most common adverse reactions were infusion reactions. The frequency of infusion reactions decreased over time with continued use of ALDURAZYME, and the majority of reactions were classified as being mild to moderate in severity. Clinical Trials in Patients 6 Years and Older A 26-week, double-blind, placebo-controlled clinical study (Study 1) of ALDURAZYME was conducted in 45 patients with MPS I, ages 6 to 43 years old, gender evenly distributed (N=23 females and 22 males). Of these 45 patients, 1 was clinically assessed as having Hurler form, 37 Hurler-Scheie, and 7 Scheie. Patients were randomized to receive either 0.58 mg/kg intravenously of ALDURAZYME per week for 26 weeks or placebo. All patients were treated with antipyretics and antihistamines prior to the infusions. Infusion reactions were reported in 32% (7 of 22) of ALDURAZYME-treated patients. The most common adverse reactions reported in patients who received ALDURAZYME were flushing, pyrexia, headache, and rash. Flushing occurred in 5 patients (23%) receiving ALDURAZYME; the other reactions were less frequent. Less common infusion reactions included angioedema (including face edema), hypotension, paresthesia, feeling hot, hyperhidrosis, tachycardia, vomiting, back pain, and cough. Other reported adverse reactions included bronchospasm, dyspnea, urticaria and pruritus. Table 2 enumerates adverse reactions and selected laboratory abnormalities that occurred during the 26-week placebo-controlled study (Study 1) that were reported in at least 2 patients more in the ALDURAZYME group than in the placebo group. Table 2: Adverse Reactions that Occurred in at Least 2 Patients More in the ALDURAZYME Group than in the Placebo Group Among Adult and Pediatric Patients with MPS I in Study 1 ALDURAZYME N=22 n (%) Placebo N=23 n (%) Blood and lymphatic system disorders Thrombocytopenia 2 (9) 0 Eye disorders Corneal opacity 2 (9) 0 General disorders and administration site conditions Chest pain 2 (9) 0 Face edema 2 (9) 0 Gravitational edema 2 (9) 0 Injection site pain 2 (9) 0 Injection site reaction 4 (18) 2 (9) Hepatobiliary disorders Hyperbilirubinemia 2 (9) 0 Infections and infestations Abscess 2 (9) 0 Upper respiratory tract infection 7 (32) 4 (17) Nervous system disorders Hyperreflexia 3 (14) 0 Paresthesia 3 (14) 1 (4) Skin and subcutaneous tissue disorders Rash 8 (36) 5 (22) Vascular disorders Hypotension 2 (9) 0 Poor venous access 3 (14) 0 All 45 patients who completed the placebo-controlled study (Study 1) continued treatment in an open-label, uncontrolled extension study (Study 2). All patients received ALDURAZYME 0.58 mg/kg of body weight once weekly for up to 182 weeks. The most serious adverse reactions reported with ALDURAZYME infusions in Study 2 were anaphylactic and hypersensitivity reactions [see Warnings and Precautions (5) ] . One patient had an anaphylactic reaction consisting of urticaria and airway obstruction and tested positive for both ALDURAZYME-specific IgG and IgE binding antibodies and complement activation. The most common adverse reactions requiring intervention were infusion reactions reported in 49% (22 of 45) of patients treated with ALDURAZYME. The most common adverse reactions reported in patients who received ALDURAZYME were rash (13%), flushing (11%), pyrexia (11%), headache (9%), abdominal pain or discomfort (9%), and injection site reaction (9%). Less commonly reported infusion reactions included nausea (7%), diarrhea (7%), feeling hot or cold (7%), vomiting (4%), pruritus (4%), arthralgia (4%), and urticaria (4%). Additional common adverse reactions included back pain and musculos