Antiidiotype Induction Therapy: Evidence for the Induction of Immune Response through the Idiotype Network in Patients with Ovarian Cancer after Administration of Anti-CA 125 Murine Monoclonal Antibody B43.13

The immune status of ovarian cancer patients receiving anti-CA 125 murine monoclonal antibody B43.13 was evaluated by measuring antiidiotypic antibodies (Ab₂), antiantiidiotypic antibodies (Ab₃), antiisotypic human antimouse antibodies (HAMA), interferon-γ, and CA125 levels in the serum. A specific assay was developed for the determination of Ab₂ antibodies using chimeric MAb B43.13. Of the 50 patients studied, 26 had elevated levels of Ab₂. Eleven of these 26 patients also had high titer of antiantiidiotypic ( Ab₃) antibodies. Eight of the 22 patients analyzed had increased interferon-γ levels. A tentative correlation was found between survival of these patients' antiidiotype induction.