As for many solid tumors, major advances in the treatment of ovarian cancer are more likely to be made through the introduction of novel targeted approaches rather than by manipulating cytotoxic chemotherapy regimens. Farletuzumab is a monoclonal antibody that binds to and blocks the function of folate receptor alpha, which is expressed in at least 90% of ovarian cancer patients. In platinum-sensitive patients experiencing the first relapse of their disease, farletuzumab enhances CA-125 responses as well as tumor response, as determined by RECIST criteria, compared with historic controls. Farletuzumab therefore represents a promising candidate for evaluation in phase III trials. The FAR-131 study is a multicenter, double-blind, randomized, placebo-controlled trial examining the safety and efficacy of two dose levels of farletuzumab in combination with carboplatin and a taxane in patients with platinum-sensitive ovarian cancer in first relapse. The primary endpoint is progression-free survival; the effects of this combination on overall survival, CA-125 response, duration of second remission, and quality of life are among the secondary objectives of this study.