ANTI-TAG-72 ANTIBODY B72.3 - IMMUNOLOGICAL AND CLINICAL EFFECTS IN OVARIAN-CARCINOMA

Based an the network theory, anti-tumor antibodies (Abl) can trigger t he immune system of the host into a response against tumor cells. Thro ugh an immunological cascade, anti-idiotypic antibodies bearing the in ternal image of epitopes of the nominal antigen (Ab2 beta) are produce d that themselves can induce cellular and humoral cytotoxic effects ag ainst the antigen-expressing tumor cell, Formation of such antibodies has been shown to be associated with prolonged survival of melanoma, c olorectal, and ovarian carcinoma patients, We studied anti-idiotypic a ntibody (Ab2) responses and clinical outcome of 31 ovarian cancer pati ents receiving the monoclonal antibody (MAb) B72.3, which targets the ovarian carcinoma associated antigen TAG-72. All patients were treated by surgery and polychemotherapy, which was followed by repeated (mean of 4) injections of 1 mg of the MAb B72.3. A remarkable anti-idiotypi c anti-B72.3 response arose in 19 patients, with 9 of them showing a m ajor response with Ab2 serum concentrations greater than 1,000 U/ml (' 'high-responders''), The median disease-free survival time, as well as the median survival time of these high-responders, was increased as c ompared to the low- or no responders, Evaluating our data, we conclude that monoclonal antibody treatment with the MAb B72.3 may induce humo ral immunological responses in about two-thirds of our study group, al though a positive clinical effect may only be expected in patients wit h excessive anti-idiotypic antibody formation.