Avalglucosidase alfa

12.1 Mechanism of Action Pompe disease (also known as glycogen storage disease type II, acid maltase deficiency, and glycogenosis type II) is an inherited disorder of glycogen metabolism caused by a deficiency of the lysosomal enzyme acid α-glucosidase (GAA) that degrades glycogen to glucose in the lysosome. GAA deficiency results in intralysosomal accumulation of glycogen in various tissues. Avalglucosidase alfa-ngpt provides an exogenous source of GAA. The M6P on avalglucosidase alfa-ngpt mediates binding to M6P receptors on the cell surface with high affinity. After binding, it is internalized and transported into lysosomes where it undergoes proteolytic cleavage that results in increased GAA enzymatic activity. Avalglucosidase alfa-ngpt then exerts enzymatic activity in cleaving glycogen.

1 INDICATIONS AND USAGE NEXVIAZYME is indicated for the treatment of patients 1 year of age and older with late-onset Pompe disease (lysosomal acid alpha-glucosidase [GAA] deficiency). NEXVIAZYME is a hydrolytic lysosomal glycogen-specific enzyme indicated for the treatment of patients 1 year of age and older with late-onset Pompe disease (lysosomal acid alpha-glucosidase [GAA] deficiency). ( 1 )

2 DOSAGE AND ADMINISTRATION Consider administering antihistamines, antipyretics, and/or corticosteroids prior to NEXVIAZYME administration to reduce the risk of IARs. ( 2.1 ) NEXVIAZYME is administered as intravenous infusion. For patients weighing ( 2.2 ): ≥30 kg, the recommended dosage is 20 mg/kg (of actual body weight) every two weeks. <30 kg, the recommended dosage is 40 mg/kg (of actual body weight) every two weeks. See the full prescribing information for dosage modifications due to hypersensitivity reactions or IARs. ( 2.3 ) Must be reconstituted and diluted prior to use. ( 2.4 ) For instructions on storage and administration, see full prescribing information. ( 2.5 , 2.6 ) 2.1 Recommendations Prior to NEXVIAZYME Treatment Prior to NEXVIAZYME administration, consider pretreating with antihistamines, antipyretics, and/or corticosteroids [see Warnings and Precautions (5.1 , 5.2) ] . NEXVIAZYME must be reconstituted and diluted prior to use [see Dosage and Administration (2.4) ] . Appropriate medical monitoring and support measures, including cardiopulmonary resuscitation equipment, should be readily available during NEXVIAZYME administration. 2.2 Recommended Dosage and Administration NEXVIAZYME is administered as intravenous infusion. For patients weighing: 30 kg or more- the recommended dosage is 20 mg/kg (of actual body weight) every two weeks [see Dosage and Administration (2.6) ] Less than 30 kg- the recommended dosage is 40 mg/kg (of actual body weight) every two weeks [see Dosage and Administration (2.6) ] The initial recommended infusion rate is 1 mg/kg/hour. Gradually increase the infusion rate every 30 minutes if there are no signs of infusion-associated reactions (IARs) [see Dosage and Administration (2.6) ] . If one or more doses are missed, restart NEXVIAZYME treatment as soon as possible, maintaining the 2 week interval between infusions thereafter. 2.3 Administration Modifications Due to Hypersensitivity Reactions and/or Infusion-Associated Reactions In the event of a severe hypersensitivity reaction (e.g., anaphylaxis) or severe infusion-associated reaction (IAR), immediately discontinue NEXVIAZYME administration and initiate appropriate medical treatment. For additional recommendations in the event of a severe hypersensitivity reaction or IAR, [ see Warnings and Precautions (5.1 , 5.2) ] . In the event of a mild to moderate hypersensitivity reaction or a mild to moderate IAR, consider temporarily holding the infusion for 30 minutes or slowing the infusion rate by 50% [see Dosage and Administration (2.6) ] and initiating appropriate medical treatment [see Warnings and Precautions (5.1 , 5.2) ] . If symptoms persist for longer than 30 minutes despite holding or slowing the infusion, stop the infusion and monitor the patient. Consider re-initiating the infusion on the same day when symptoms subside at 50% of the rate at which the reaction occurred with appropriate pretreatment. If symptoms subside after holding the infusion, resume infusion at 50% of the rate at which the reaction occurred, and subsequently increase the infusion rate every 15 to 30 minutes by 50% as tolerated. Alternatively, if symptoms subside after slowing the infusion, complete the infusion at the reduced rate as tolerated. Starting with the next infusion, increase the infusion rate until the infusion rate at which the reaction occurred is reached. Consider continuing to increase the infusion rate in a stepwise manner until reaching the recommended infusion rate. Closely monitor the patient. 2.4 Reconstitution and Dilution Instructions Reconstitute and dilute NEXVIAZYME in the following manner. Use aseptic technique during preparation. Reconstitute the Lyophilized Powder Determine the number of NEXVIAZYME vials to be reconstituted 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 required number of NEXVIAZYME vials from the refrigerator and allow the vials to sit for 30 minutes at room temperature 20°C to 25°C (68°F to 77°F) before use. Reconstitute each vial by injecting 10 mL of Sterile Water for Injection, down the inside wall of each vial. Avoid adding the Sterile Water for Injection to the vial forcefully or directly onto the lyophilized powder to minimize foaming. Gently tilt and roll each vial to enhance the dissolution process. Do not invert, swirl, or shake the vial. Allow the solution to become dissolved. Each vial will yield a concentration of 100 mg/10 mL (10 mg/mL) of avalglucosidase alfa-ngpt. Visually inspect the reconstituted solution in the vials for particulate matter and discoloration. The reconstituted solution should be clear, colorless to pale-yellow. Discard if particles are present or the solution is discolored. Dilute the Reconstituted Solution Select an appropriate size 5% Dextrose Injection infusion bag and prepare by removing a volume equal to the required NEXVIAZYME volume and

6 ADVERSE REACTIONS The following serious adverse reactions are discussed in greater detail in other sections of the labeling: Hypersensitivity Reactions Including Anaphylaxis [see Warnings and Precautions (5.1) ] Infusion-Associated Reactions (IARs) [see Warnings and Precautions (5.2) ] The most common adverse reactions (>5%) were headache, fatigue, diarrhea, nausea, arthralgia, dizziness, myalgia, pruritus, vomiting, dyspnea, erythema, paresthesia and urticaria. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Genzyme at 1-800-633-1610, option 1 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. Adverse Reactions from Clinical Trials in the Pompe Disease Population The pooled safety analysis from 4 clinical trials in the Pompe disease population (including Study 1) with a mean exposure of 26 months and up to 85 months of treatment included a total of 141 NEXVIAZYME-treated patients (118 adult and 23 pediatric patients [see Clinical Studies (14.1) ] . Adverse reactions were similar across both adult and pediatric populations. Serious adverse reactions reported in 2 or more NEXVIAZYME-treated patients were respiratory distress, chills, and pyrexia. A total of 4 NEXVIAZYME-treated patients in clinical trials permanently discontinued NEXVIAZYME due to adverse reactions, including 3 patients who discontinued the treatment because of a serious adverse reaction. The most frequently reported adverse reactions (>5%) in the pooled safety population were abdominal pain, arthralgia, chills, diarrhea, dizziness, dyspnea, erythema, fatigue, flushing, headache, hypertension, hypotension, myalgia, nausea, pruritus, pyrexia, rash, vomiting, and urticaria. Hypersensitivity reactions were reported in 67 (48%) NEXVIAZYME-treated patients, including 6 (4%) patients who reported severe hypersensitivity reactions. Symptoms of severe hypersensitivity reactions (e.g., anaphylaxis) included chest discomfort, erythema, generalized edema, hypotension, hypoxia, rash, respiratory distress, tongue edema, and urticaria. IARs were reported in 48 (34%) NEXVIAZYME-treated patients. Six (4%) NEXVIAZYME-treated patients reported 13 severe IARs including symptoms of chest discomfort, decreased or increased blood pressure, dysphagia, erythema, generalized edema, hypoxia, nausea, respiratory distress, tongue edema, and urticaria. IARs reported in more than 1 patient included chest discomfort, cyanosis, decreased or increased blood pressure, diarrhea, dizziness, erythema, fatigue, feeling hot or cold, generalized edema, headache, hyperhidrosis, hypoxia, influenza-like illness, nausea, pain, pruritus, pyrexia, rash, respiratory distress, tachycardia, throat irritation, tongue edema, tremor, urticaria, and vomiting. Adverse Reactions from Clinical Trials in Late-Onset Pompe Disease (LOPD) In Study 1, 100 patients aged 16 to 78 years of age with LOPD (naïve to enzyme replacement therapy) were treated with either 20 mg/kg of NEXVIAZYME (n=51) or 20 mg/kg of alglucosidase alfa (n=49) given every other week as an intravenous infusion for 49 weeks followed by an open-label extension period [see Clinical Studies (14.1) ] . During the double-blind active-controlled period of 49 weeks, serious adverse reactions were reported in 1 (2%) patient treated with NEXVIAZYME and in 3 (6%) patients treated with alglucosidase alfa. The most frequently reported adverse reactions in (>5%) NEXVIAZYME-treated patients were headache, fatigue, diarrhea, nausea, arthralgia, dizziness, myalgia, pruritus, vomiting, dyspnea, erythema, paresthesia, and urticaria. IARs were reported in 13 (25%) of the NEXVIAZYME-treated patients. IARs reported in more than 1 patient on NEXVIAZYME were mild to moderate and included headache, diarrhea, pruritus, urticaria, and rash. None of them were severe IARs. IARs were reported in 16 (33%) patients treated with alglucosidase alfa. IARs reported in more than 1 patient on alglucosidase alfa were mild to severe and included dizziness, flushing, dyspnea, nausea, pruritis, rash, erythema, chills, and feeling hot. Severe IARs were reported in 2 patients treated with alglucosidase alfa. Table 4 summarizes the adverse reactions that occurred in at least 3 NEXVIAZYME-treated patients (≥6%) in Study 1. Study 1 was not designed to demonstrate a statistically significant difference in the incidence of adverse reactions in the NEXVIAZYME and the alglucosidase alfa treatment groups. Table 4: Adverse Reactions Reported in at Least 6% of NEXVIAZYME-Treated Patients with LOPD in Study 1 Adverse Reaction NEXVIAZYME (N=51) n (%) Alglucosidase Alfa (N=49) n (%) Headache 11 (22%) 16 (33%) Fatigue 9 (18%) 7 (14%) Diarrhea 6 (12%) 8 (16%) Nausea 6 (12%) 7 (14%) Arthralgi