Time to progression in metastatic breast cancer patients treated with epirubicin is not improved by the addition of either cisplatin or lonidamine: final results of a phase III study with a factorial design.

To investigate the value of the addition of either cisplatin (CDDP) or lonidamine (LND) to epirubicin (EPI) in the first-line treatment of advanced breast cancer. Three hundred seventy-one metastatic breast cancer patients with no prior systemic chemotherapy for advanced disease were randomized to receive either EPI alone (60 mg/m(2) on days 1 and 2 every 21 days), EPI and CDDP (30 mg/m(2) on days 1 and 2 every 21 days), EPI and LND (450 mg orally daily, given continuously), or EPI, CDDP, and LND. Time to progression, response rates, side effects, and survival were compared according to the 2 x 2 factorial design of this study. The groups were well balanced with respect to prognostic factors. Time to progression did not differ in the comparison between CDDP arms and non-CDDP arms (median, 10.9 months v 9.4 months, respectively; P =.10) or between that of LND arms and non-LND arms (median, 10.8 months v 9.9 months, respectively; P =.47), nor did overall survival. The response rate did not significantly differ in the comparison between LND arms and non-LND arms (62.9% v 54.0%, P =.08). No difference in treatment activity was observed between CDDP arms and non-CDDP arms. Toxicity was significantly higher in the CDDP arms, leading to CDDP dose adjustment in 40% of cases. The most frequent side effects were of a hematologic and gastrointestinal nature. The addition of LND produced more myalgias and fatigue. Neither CDDP nor LND was able to significantly improve the time to progression obtained by EPI. CDDP, however, significantly worsened the drug's tolerability.