A review of tositumomab and I¹³¹ tositumomab radioimmunotherapy for the treatment of follicular lymphoma

Abstract

The CD20 antigen has become a major therapeutic target in the management of follicular and other Bcell non-Hodgkin’s lymphomas. The murine monoclonal antibody, tositumomab, on binding CD20, is able to induce antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity and apoptosis. In addition, when radioiodinated, the antibody exploits the tumour’s sensitivity to ionising radiation by direct targeting of the malignant cell. Tositumomab and Iodine (I¹³¹) tositumomab (Bexxar^®, GlaxoSmithKline, Philadelphia, PA, USA) is administered in two steps. The dosimetric step determines individual patient pharmacokinetics, allowing a patient- specific dose to be calculated. This is followed by the therapeutic step, with administration of the therapeutic dose between 7 and 14 days after the dosimetric dose. Over a decade’s worth of experience in clinical trials has determined the efficacy and safety of the regimen in a variety of clinical ci-rcumstances; establishment of exactly where the regimen fits amongst the algorithm for the management of follicular lymphoma continues.

• CD20
• follicular lymphoma
• iodine I131 tositumomab
• monoclonal antibody
• radioimmunotherapy
• tositumomab