MONOCLONAL-ANTIBODIES IN THE TREATMENT OF NON-HODGKINS-LYMPHOMA

Recent advances in the development of monoclonal antibodies and their genetically engineered derivatives have resulted in rekindled interest in cancer immunotherapy. The main rationale for using antibody therapy in cancer treatment is to increase the specificity of the cytotoxic effects. Monoclonal antibodies have been used either as 'naked' antibodies in which host effector mechanisms are recruited to eradicate the tumour cells or, more often, as a delivery system for radiotherapy or toxins. Although some antibodies used have been directed at tumour-specific antigens (idiotypic proteins expressed on lymphoma cell surfaces), the majority are directed at tumour-associated antigens. As a result, nonspecific toxicity is common. Mixed results have been obtained in patients with refractory non-Hodgkin's lymphoma. Transient responses are common, but only a few patients have achieved durable long term disease-free survival. Adverse reactions are limited mainly to allergic reactions, bone marrow toxicity and the development of anti-globulin responses either to the native antibodies or to the conjugated toxins. In patients receiving toxin-conjugated monoclonal antibodies, a further complication not uncommonly seen is the leaking capillary syndrome. Further work is needed to define the optimum antigen to be targeted and the clinical setting in which monoclonal antibody therapy should be used.