Radioimmunotherapy of Non Hodgkins Lymphoma

Non Hodgkins lymphomas are the most common type of lymphoma and while higher grade lymphomas can be cured with chemotherapy, lower grade tumors tend to be hard to control and often progress to be lethality after developing drug resistance and transforming to higher grades which are less treatable. About 90% of these lymphomas are of B cell histology and thus can be targeted by antibodies reactive with B cell antigens, either specific to the tumor (anti idiotypic) or specific to the B cell's differentiation stage (differentiation antigens). Two anti CD20 radioantibodies are now approved by the US FDA for treatment of NHL, one with 1131 as a label, the other with Y90 as a label. This lecture will review the clinical experience with both agents in patients with drug resistant and refractory NHL at both non myeloablative (standard) and mycloablative (investigational) dose levels. Further, the recent very exciting experience with 1131 anti CD20 (1-131 tositumomab) in the initial therapy of NHL will be reviewed, an experience which has reported a 95% response rate