Caelyx in malignant mesothelioma: a phase II EORTC study

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.

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.

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.

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.