Bexxar(tositumomab)DARYA OSMAN HUSSEIN

GENERAL INFORMATIONTherapeutic class:

Antineoplastic agent

Pharmacologic class:Monoclonal antibody

APPLICATIONUsed alone or in combination with iodine I 131

Used to treat CD20-positive, relapsed or refractory non-Hodgkin's lymphoma

Not used for initial treatment of patients with CD20-positive NHL

Used only as a single course of treatment

Non-Hodgkin’s Lymphoma

MECHANISM OF ACTIONBinds to the CD20 (human B-lymphocyte restricted differentiation antigen) antigen

This antigen is found on >90% of B-cell NHL

Bexxar acts through:Addition of ionizing radiationInduction of apoptosisComplement dependent cytotoxicityAntibody-dependent cellular toxicity

DOSEGiven as IV solution

Dose for non-Hodgkin's lymphoma is tositumomab 450mg IV infusion over 60 minutes

Follow by I-131 tositumomab dose (calculated to deliver 75cGy total body irradiation for patients with normal platelet count) for 7 to 14 days

For those with decreased platelet count therapeutic dose adjusted to 65cGy total body irradiation

Dosing Schedule

CLEARANCEAverage clearance of the drug 68.2 mg/hr

Patients with high tumor burden, splenomegaly, or bone marrow involvement have faster clearance and shorter terminal half-life

The medial total body effective half-life is 67 hours

Elimination of Iodine – 131 occurs by decay and is excreted in urine

After five days whole body clearance is 67% with 98% of clearance accounted for in urine

Physical Decay ChartIodine – 131

T ½ = 8.04 days

Storage requirementsStore at 36F to 46F (2oC – 8oC) and protect from strong light

Thaw directly prior to administration and Do not shake

When diluted tositumomab stable for 24 hours refrigerated and 8 hours at room temperature

Thawed I131 tositumomab stable for up to 8 hours at room temperature

Dose preparation and disposalMust be prepared directly before administration

Unused portion and infusion set components must be discarded according to laws regarding radioactive and biohazardous waste

MONITORINGMonitor for infusion reactions

decreased rate by 50% for mild – moderate reactionsInterrupt infusion for serious reactions and resume at 50% of original if reaction resolves

Monitor for grade 3 or 4 cytopenias up to 3 months after treatment (primarily thrombocytopenia and neutropenia

Life-long monitoring for hypothyroidism

PREGNANCY AND BREASTFEEDINGPregnancy

High risk to fetus in all trimestersMales and females should used contraception to prevent

pregnancy during and for 12 months after stopping drug

Breastfeeding:Harmful to infant

PRECAUTIONSSerious allergic reactions (i.e. anaphylaxis – rash, itching, fever, chills, light-headedness or dizziness, nausea, trouble breathing or swelling of hands, face, mouth or throat)

Causes susceptibility to infection (because of temporary decreased number of WBCs)

Bleeding (due to decreased number of platelets)

May increase chance of certain cancer types or thyroid problems

SIDE EFFECTS(require immediate medical attention)

SIDE EFFECTS(do not require immediate medical attention)