Abagovomab: an anti-idiotypic CA-125 targeted immunotherapeutic agent for ovarian cancer.

Ovarian cancer remains the leading cause of death due to gynecologic malignancies. Most patients present with advanced disease at the time of diagnosis. Although many have a good initial response to surgical debulking and platinum-based chemotherapy, relapse is common, with the eventual development of chemotherapy resistance. Innovative treatments are needed in the remission setting to prolong the disease-free interval or prevent recurrence. Abagovomab is a murine monoclonal anti-idiotypic antibody (molecular weight: 165-175 kDa) that functionally imitates the tumor-associated antigen, CA-125. It has been shown to be well tolerated and to induce a sustained immune response in initial Phase I and II clinical trials. An ongoing, double-blind, placebo-controlled, multicenter, Phase III trial (MIMOSA) completed its double-blind period in December 2010 and will compare abagovomab maintenance therapy to placebo, which will definitively determine the efficacy of this immunotherapeutic approach in patients with ovarian cancer.