The recognition of the activity of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in metastatic breast cancer led to attempts to combine this drug with other active agents. Two agents that have received particular attention are doxorubicin and cisplatin. Initial pilot and phase I trials by the Eastern Cooperative Oncology Group (ECOG) led to the development of a three-arm, prospective randomized trial comparing single-agent doxorubicin, single-agent paclitaxel, and the combination of doxorubicin and paclitaxel (E 1193). This trial is currently closed to accrual and the initial results are being analyzed. Based on data from Gianni et al (J Clin Oncol 13:2688-2699, 1995), the ECOG is currently involved in two trials attempting both to confirm the superior activity of the regimen used by Gianni et al and, in a phase I/II trial, to ameliorate its cardiac toxicity through the addition of dexrazoxane. Similarly, both the ECOG and the Hoosier Oncology Group were unable to confirm the strikingly positive results obtained by the Vancouver group when cisplatin was combined with paclitaxel (Semin Oncol 22:108-111, 1995 [suppl 6]: Proc Am Soc Clin Oncol 13:71, 1994 [abstr 88]). Indiana University investigators are currently involved in a phase I trial attempting to combine carboplatin and paclitaxel in a biweekly schedule.