Background: The use of doxorubicin has shown some activity in malignant mesothelioma but prolonged administration is hampered by cardiotoxicity. Caelyx, a new liposomal and pegylated form of doxorubicin has shown a better pharmacokinetic and toxic profile then doxorubicin. In a phase II study, the efficacy and toxicity of Caelyx was tested in previously untreated patients with malignant pleural mesothelioma.
Patients and methods: Thirty-three patients who had measurable or evaluable histologically confirmed malignant pleural mesothelioma were included in the study. Caelyx (45 mg/m2) was given i.v. on outpatient base every four weeks for nine cycles or till progression or unacceptable toxicity occurred.
Results: Of the 33 patients, 32 were evaluable for toxicity and 31 for response. Two patients had a partial response (6%, 95% confidence interval: 0.2%-20.2%). The median survival was 13 months. Forty percent of the patients received >6 cycles. Toxicity was mild with palmar plantar erythrodysesthesia being most pronounced (62% grade 1-2, 6% grade 3) and of limited duration. Ten percent of patients had grade 3 anemia and 3% grade 3 thrombocytopenia. Two patients (6%) had grade 3 or 4 cardiac toxicity, which was not drug related.
Conclusion: At the prescribed dose, single agent Caelyx is well tolerated but its activity in chemotherapy-naive mesothelioma patients does not warrant further investigation as a single agent.