Effectiveness of cisplatin, paclitaxel, and suramin against human malignant mesothelioma xenografts in athymic nude mice

Background and Objectives: Malignant mesothelioma has a poor prognosis and is refractory to many agents. The antitumor effectiveness of cisplatin, paclitaxel, and suramin as single agents and in combination was evaluated in vivo against four lines of human pleural malignant mesothelioma xenografts in athymic nude mice, including one epithelial type and three fibrosarcomatous. Methods: After growth of tumors occurred by day 54 or 55, mice were randomized in groups of four each to receive either cisplatin 4 mg/kg intraperitoneally weekly x5, or paclitaxel (Taxol) 12.5 mg/kg subcutaneously daily 5 days/week for 3 consecutive weeks, or suramin 60 mg/kg intraperitoneally daily x4, versus controls treated with normal saline. Results: Cisplatin was very effective against one line and also to a lesser degree against another line. Paclitaxel showed antitumor effects similar to cisplatin, being very effective in one line, and also showed good activity in another line. Suramin was basically inactive in all four lines. Following the results obtained with these single agents, it was decided to evaluate the combination of cisplatin and paclitaxel, which resulted in more pronounced antitumor effect in all four cell lines. Conclusions: These results indicate that the combination of cisplatin and paclitaxel is superior to each agent alone in this model, and that it deserves to be evaluated in patients with malignant mesothelioma.