Lack of synergy between cisplatin and cytarabine against ovarian carcinoma in vitro.

Synergy has been reported for the combination of cisplatin and cytarabine in a murine model and in several human cell lines in vitro. Clinical trials are under way with this combination. However, we were unable to demonstrate any significant synergistic interaction between these two agents in two human ovarian carcinoma cell lines with either 4-hour or continuous concurrent exposure in vitro at drug concentration producing 1-2 logs of cell kill. Synergy between these two drugs may be limited to unique cell lines and tumors.