This randomized placebo-controlled double-blind parallel study demonstrated the potential safety and effectiveness of itraconazole as an adjunct therapy to paclitaxel and carboplatin chemotherapy in improving therapeutic response and reducing chemotherapy resistance in patients with advanced epithelial ovarian cancer, which was translated by significant improvements in patients’ response, overall response rate, disease control rate, and progression-free survival, alongside significant declines in both CA-125 and P-glycoprotein serum concentrations. This evidence concerns the gene ABCB1 and ovarian carcinoma.