e infusional toxicity. After complete resolution of severe infusional toxicity, infusion may be resumed with a 50% reduction in the rate of infusion.
Patients with ≥150,000 platelets/mm3: The recommended dose is the activity of Iodine-131 calculated to deliver 75 cGy total body irradiation and 35 mg Tositumomab, administered intravenously over 20 minutes.
Patients with NCI Grade 1 thrombocytopenia (platelet counts ≥100,000 but <150,000 platelets/mm3): The recommended dose is the activity of Iodine-131 calculated to deliver 65 cGy total body irradiation and 35 mg Tositumomab, administered intravenously over 20 minutes.
Concomitant Medications
The safety of the BEXXAR therapeutic regimen was established in studies in which all patients received the following concurrent medications:
Thyroid protective agents: Saturated solution of potassium iodide (SSKI) 4 drops orally t.i.d.; Lugol’s solution 20 drops orally t.i.d.; or potassium iodide tablets 130 mg orally q.d. Thyroid protective agents should be initiated at least 24 hours prior to administration of the Iodine I 131 Tositumomab dosimetric dose and continued until 2 weeks after administration of the Iodine I 131 Tositumomab therapeutic dose.
Patients should not receive the dosimetric dose of Iodine I 131 Tositumomab if they have not yet received at least three doses of SSKI, three doses of Lugol’s solution, or one dose of 130 mg potassium iodide tablet (at least 24 hours prior to the dosimetric dose).
Acetaminophen 650 mg orally and diphenhydramine 50 mg orally 30 minutes prior to administration of Tositumomab in the dosimetric and therapeutic steps.
The BEXXAR therapeutic regimen is administered via an IV tubing set with an in-line 0.22 micron filter. THE SAME IV TUBING SET AND FILTER MUST BE USED THROUGHOUT THE ENTIRE DOSIMETRIC OR THERAPEUTIC STEP. A CHANGE IN FILTER CAN RESULT IN LOSS OF DRUG.
Figure1 shows an overview of the dosing schedule.
Figure 1
Dosing Schedule
PREPARATION OF THE BEXXAR THERAPEUTIC REGIMEN
GENERAL
Read all directions thoroughly and assemble all materials before preparing the dose for administration.
The Iodine I 131 Tositumomab dosimetric and therapeutic doses should be measured by a suitable radioactivity calibration system immediately prior to administration. The dose calibrator must be operated in accordance with the manufacturer’s specifications and quality control for the measurement of Iodine-131.
All supplies for preparation and administration of the BEXXAR therapeutic regimen should be sterile. Use appropriate aseptic technique and radiation precautions for the preparation of the components of the BEXXAR therapeutic regimen.
Waterproof gloves should be utilized in the preparation and administration of the product. Iodine I 131 Tositumomab doses should be prepared, assayed, and administered by personnel who are licensed to handle and/or administer radionuclides. Appropriate shielding should be used during preparation and administration of the product.
Restrictions on patient contact with others and release from the hospital must follow all applicable federal, state, and institutional regulations.
Preparation for the Dosimetric Step
Tositumomab Dose
Required materials not supplied:
A. One 50 mL syringe with attached 18-gauge needle (to withdraw 450 mg of Tositumomab from two vials each containing 225 mg Tos
