Source: FDA, National Drug Code (US) Revision Year: 2026
ZANVASTRO is indicated for the treatment of Alexander disease in pediatric and adult patients.
Administer ZANVASTRO intrathecally after dilution using a lumbar puncture by, or under the direction of, healthcare professionals experienced in performing lumbar punctures.
The recommended dosage of ZANVASTRO is 50 mg intrathecally every 3 months.
The final dose volume of the intrathecal injection is determined by the patient's age [see Dilution and Preparation Instructions (2.2)].
If a dose of ZANVASTRO is missed, administer ZANVASTRO as soon as possible. Resume treatment at the recommended dosing frequency from the date of the most recently administered dose.
Read the entire Instructions for Use provided in the carton before diluting and preparing ZANVASTRO for intrathecal administration.
Each carton contains 1 vial of ZANVASTRO and 1 vial of diluent to be used together to prepare a single dose.
The diluent vial contains more volume than needed. Discard excess diluent prior to dilution as instructed below.
Prepare ZANVASTRO according to the instructions below and in Table 1.
Use aseptic technique when preparing and administering ZANVASTRO intrathecally.
1. Use a 3 mL and/or 10 mL syringe with an 18G to 22G needle to withdraw excess aCSF diluent from the diluent vial as determined by Table 1 based on the patient's age. Keep the diluent vial containing the remaining diluent for Step 3. Discard the syringe(s) containing the excess diluent.
2. Use a 3 mL syringe with an 18G to 22G needle to withdraw 2.8 mL of ZANVASTRO from the ZANVASTRO vial.
3. Add the withdrawn volume of ZANVASTRO to the diluent vial.
4. Gently invert the diluent vial (which now also contains ZANVASTRO) several times to mix the solution.
5. Attach an 18G or 19G filter needle (5 micron) to a 20 mL syringe. Withdraw the recommended dose volume of diluted ZANVASTRO from the diluent vial as determined by Table 1 based on the patient's age.
6. Remove the filter needle. Attach a syringe tip cap to the prepared dosing syringe.
7. Label the prepared dosing syringe per institution procedures prior to use or transport.
8. Discard any unused portion of the diluted solution and any unused contents of the ZANVASTRO vial.
Table 1. ZANVASTRO Dilution Procedure:
| Patient Age | Volume of excess aCSF diluent to withdraw from the diluent vial and discard | Volume of ZANVASTRO to add to the diluent vial | Volume of diluted ZANVASTRO to withdraw from the diluent vial for administration (dose volume) |
| Less than 2 years old | 12.6 mL | 2.8 mL | 10 mL |
| 2 to 7 years old (inclusive) | 7.0 mL | 2.8 mL | 15 mL |
| 8 years old and above | 1.4 mL | 2.8 mL | 20 mL |
ZANVASTRO contains no preservatives. Once drawn into the dosing syringe, the solution must be administered within:
Do not freeze. Do not expose to heat. Protect the prepared dosing syringe from light as a precaution.
If the prepared dosing syringe is refrigerated prior to administration, allow the dosing syringe to warm to room temperature for at least 30 minutes prior to use for patient comfort. Do not use external heat sources to warm the dosing syringe [see Storage and Handling (16.2)].
Prior to administration, remove a volume of the patient's CSF approximately equal to the intended dose volume as appropriate for age, based on Table 2, using a lumbar puncture needle.
Table 2. Recommended Injection Dose Volume:
| Age | Injection Dose Volume After Dilution |
| Less than 2 years old | 10 mL |
| 2 years old to 7 years old (inclusive) | 15 mL |
| 8 years old and above | 20 mL |
Administer ZANVASTRO as an intrathecal bolus injection over 1 to 3 minutes using the lumbar puncture needle. Do not flush the needle or any attached extension catheter, if used, after administration.
Discard the dosing syringe.
Store the ZANVASTRO vial and diluent vial in the refrigerator between 2°C and 8°C (36°F and 46°F) in the original carton to protect from light.
Once taken out of the refrigerator, the ZANVASTRO vial and diluent vial can be stored at room temperature up to 30°C (86°F) in the original carton for up to 14 days. If not used within the 14 days stored at room temperature, discard ZANVASTRO.
Do not freeze. Do not expose to heat. Protect from light as a precaution.
See Dosage and Administration (2.2) for instructions on how to store ZANVASTRO diluted solution.
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