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MYOZYME® (alglucosidase alfa) [see DESCRIPTION] is a lysosomal glycogen-specific enzyme indicated for use in patients with Pompe disease (GAA deficiency). MYOZYME has been shown to improve ventilator-free survival in patients with infantile-onset Pompe disease as compared to an untreated historical control, whereas use of MYOZYME in patients with other forms of Pompe disease has not been adequately studied to assure safety and efficacy [see Clinical Studies].
DOSAGE AND ADMINISTRATION
The recommended dosage regimen of MYOZYME is 20 mg/kg body weight administered every 2 weeks as an intravenous infusion.
Instructions for Use
MYOZYME does not contain any preservatives. Vials are single-use only. Any unused product should be discarded.
The total volume of infusion is determined by the patient's body weight and should be administered over approximately 4 hours.
Infusions should be administered in a step-wise manner using an infusion pump. The initial infusion rate should be no more than 1 mg/kg/hr. The infusion rate may be increased by 2 mg/kg/hr every 30 minutes, after patient tolerance to the infusion rate is established, until a maximum rate of 7 mg/kg/hr is reached. Vital signs should be obtained at the end of each step. If the patient is stable, MYOZYME may be administered at the maximum rate of 7 mg/kg/hr until the infusion is completed. The infusion rate may be slowed and/or temporarily stopped in the event of infusion reactions. See Table 1 below for the rate of infusion at each step, expressed as mL/hr based on the recommended infusion volume by patient weight.
Table 1: Recommended Infusion Volumes and Rates
|Patient Weight Range (kg)||Total infusion volume (mL)||Step 1 1 mg/kg/hr (mL/hr)||Step 2 3 mg/kg/hr (mL/hr)||Step 3 5 mg/kg/hr (mL/hr)||Step 4 7 mg/kg/hr (mL/hr)|
|10.1 - 20||100||5||15||25||35|
|20.1 – 30||150||8||23||38||53|
|30.1 – 35||200||10||30||50||70|
|35.1 – 50||250||13||38||63||88|
|50.1 – 60||300||15||45||75||105|
|60.1 – 100||500||25||75||125||175|
|100.1 – 120||600||30||90||150||210|
|120.1 – 140||700||35||105||175||245|
|140.1 – 160||800||40||120||200||280|
|160.1 – 180||900||45||135||225||315|
|180.1 – 200||1000||50||150||250||350|
Reconstitution, dilution and administration
MYOZYME should be reconstituted, diluted and administered by a healthcare professional.
Use aseptic technique during preparation. Do not use filter needles during preparation.
1. Determine the number of vials to be reconstituted based on the individual patient's weight and the recommended dose of 20 mg/kg.
Patient weight (kg) x dose (mg/kg) = patient dose (in mg)
Patient dose (in mg) divided by 50 mg/vial = number of vials to reconstitute. If the number of vials includes a fraction, round up to the next whole number.
Example: Patient weight (16 kg) x dose (20 mg/kg) = patient dose (320 mg)
320 mg divided by 50 mg/vial = 6.4 vials; therefore, 7 vials should be reconstituted
Remove the required number of vials from the refrigerator and allow them to reach room temperature prior to reconstitution (approximately 30 minutes).
2. Reconstitute each MYOZYME vial by slowly injecting 10.3 mL of Sterile Water for Injection, USP to the inside wall of each vial. Each vial will yield 5 mg/mL. The total extractable dose per vial is 50 mg per 10 mL. Avoid forceful impact of the water for injection on the powder and avoid foaming. This is done by slow drop-wise addition of the water for injection down the inside of the vial and not directly onto the lyophilized cake. Tilt and roll each vial gently. Do not invert, swirl, or shake.
3. The reconstituted MYOZYME solution should be protected from light.
4. Perform an immediate visual inspection on the reconstituted vials for particulate matter and discoloration. If upon immediate inspection opaque particles are observed or if the solution is discolored do not use. The reconstituted solution may occasionally contain some alglucosidase alfa particles (typically less than 10 in a vial) in the form of thin white strands or translucent fibers subsequent to the initial inspection. This may also happen following dilution for infusion. These particles have been shown to contain alglucosidase alfa and may appear after the initial reconstitution step and increase over time. Studies have shown that these particles are removed via in-line filtration without having a detectable effect on the purity or strength.
5. MYOZYME should be diluted in 0.9% Sodium Chloride for Injection, USP, immediately after reconstitution, to a final MYOZYME concentration of 0.5 to 4 mg/mL. See Table 1 for the recommended total infusion volume based on patient weight.
6. Slowly withdraw the reconstituted solution from each vial. Avoid foaming in the syringe.
7. Remove airspace from the infusion bag to minimize particle formation due to the sensitivity of MYOZYME to air-liquid interfaces.
8. Add the reconstituted MYOZYME solution slowly and directly into the sodium chloride solution. Do not add directly into airspace that may remain within the infusion bag. Avoid foaming in the infusion bag.
9. Gently invert or massage the infusion bag to mix. Do not shake.
10. Administer MYOZYME using an in-line low protein- binding 0.2 μm filter.
MYOZYME should not be infused in the same intravenous line with other products.
MYOZYME does not contain any preservatives. Vials are single-use only. Discard any unused product.
Dosage Forms And Strengths
MYOZYME is supplied as a sterile, nonpyrogenic, white to off-white, lyophilized cake or powder for reconstitution with Sterile Water for Injection, USP to yield a concentration of 5 mg/mL; and then further diluted with 0.9% Sodium Chloride for Injection, USP for intravenous infusion.
Single-use vials are available in 50 mg dosage only.
Storage And Handling
MYOZYME 50 mg vials are supplied as a sterile, nonpyrogenic, white to off-white lyophilized cake or powder. MYOZYME is supplied in single-use, clear Type I glass 20 mL (cc) vials. The closure consists of a siliconized butyl stopper and an aluminum seal with a plastic flip-off cap.
Store MYOZYME under refrigeration between 2° to 8°C (36° to 46°F). Do not use MYOZYME after the expiration date on the vial.
The reconstituted and diluted solution should be administered without delay. If immediate use is not possible, the reconstituted and diluted solution is stable for up to 24 hours at 2° to 8°C (36° to 46°F). Storage of the reconstituted solution at room temperature is not recommended. The reconstituted and diluted MYOZYME solution should be protected from light. DO NOT FREEZE OR SHAKE.
MYOZYME is manufactured and distributed by: Genzyme Corporation., 500 Kendall Street, Cambridge, MA 02142. 1-800-745-4447. Rev: July 2012
Last reviewed on RxList: 7/27/2012
This monograph has been modified to include the generic and brand name in many instances.
Additional Myozyme Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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