Two dose levels of ifosfamide in malignant mesothelioma.

Thirty-one consecutive patients with histologically proven and symptomatic malignant mesothelioma were treated with two dose levels of ifosfamide. The first group of 15 patients were given 2.3 g/m2/day for 5 days (group A) and the following 16 patients were treated with 1.2 g/m2/day for 5 days of ifosfamide (group B). Treatment cycles were repeated every 3 weeks. While the partial response rate (PR) in group A was 38.5%, it was only 6.25% in group B (P > 0.05). The 95% confidence interval for the difference in PR rates was 3.3-61.2% > The overall survival (OAS) of groups A and B were similar (8 months and 9 months, respectively). Higher Grade 3-4 myelotoxicity was observed in group A when compared to group B (30.8% vs. 18.7%; P > 0.05). In conclusion, a favourable response rate could be achieved in malignant mesothelioma with high dose ifosfamide at the cost of increased toxicity.