Background: This study investigated the feasibility and efficacy of doxorubicin dose-escalated chemotherapy in combination with ifosfamide in patients with malignant mesothelioma.
Patients and methods: In this single institution phase II study, 24 chemotherapy-naive, eligible patients were entered. The chemotherapy regimen consisted of doxorubicin 75 mg/m2 in combination with ifosfamide 5 gr/m2 given as a continuous 24 hour infusion, every 21 days with either rhG-CSF (5 micrograms/kg) or rhGM-CSF (250 micrograms/m2) as haematopoietic support from d3 to d14. Cycles were repeated every 3 weeks.
Results: We treated 24 patients, of whom 22 are evaluable for tumour response. One of the two inevaluable patients died from a cerebral haemorrhage during a period of grade III thrombocytopenia after the second course. In 7 patients a partial response was observed, resulting in a response rate of 32% (95% confidence interval 13%-51%). Median response duration was 6 months (range 1-13) and median survival was 7 months (range 1-18).
Conclusions: The high-dose regimen with growth factor support is feasible in this group of patients and leads to an interesting response rate. The limiting toxicity for further dose increments and more courses of treatment, was cumulative thrombocytopenia. There seems to be a subgroup of patients with malignant mesothelioma which is less susceptible to develop thrombocytopenia. However, the overall toxicity and the poor response duration limit the use of this schedule in the treatment of malignant mesothelioma.