2.1 Recommended Dosage

The recommended dosage of VORAXAZE is 50 Units per kilogram (kg) as a single intravenous injection administered over 5 minutes. Flush intravenous line before and after administration.

2.2 Concomitant Use with Leucovorin Rescue

When administering VORAXAZE concomitantly with leucovorin, administer leucovorin at least 2 hours before or 2 hours after the VORAXAZE dose [see Drug Interactions (7.1)].

For the first 48 hours after a dose of VORAXAZE:

• Administer the same leucovorin dosage given prior to the VORAXAZE dose.

Beyond 48 hours after a dose of VORAXAZE:

• Determine the leucovorin dosage based on the measured methotrexate concentration. Do not discontinue leucovorin based on the determination of a single methotrexate concentration below the leucovorin rescue threshold.
• Continue leucovorin until the methotrexate concentration has been maintained below the leucovorin rescue threshold for a minimum of 3 days.

Continue intravenous hydration and urinary alkalinization as indicated.

When measuring methotrexate concentrations following a VORAXAZE dose, a chromatographic method is preferred over an immunoassay [see Warnings and Precautions (5.2)].

2.3 Preparation

Reconstitute the contents of the vial with 1 mL of 0.9% Sodium Chloride Injection, USP.

Roll and tilt the vial gently to mix. Do not shake.

Inspect the vial and discard VORAXAZE if the solution is not clear, colorless, and free of particulate matter.

Use reconstituted VORAXAZE immediately or store under refrigeration at 36° to 46°F (2° to 8°C) for up to 4 hours if not used immediately. VORAXAZE contains no preservative and is supplied as a single-dose vial. Discard any unused product.