Interferon alpha and doxorubicin in malignant mesothelioma: a phase II study.

Malignant mesothelioma is a tumour which is generally resistant to chemotherapy. While the addition of interferon to chemotherapy improves response rates in some other malignancies, such a combination has not been evaluated in the treatment of mesothelioma. To assess the anti-tumour effects and toxicity of interferon-alpha combined with doxorubicin in the treatment of pleural mesothelioma. Twenty five patients (mean age 54 +/- 11 years) were enrolled in a phase II study. All patients had a confirmed histological diagnosis, measurable tumour, a life expectancy of at least three months, and no prior chemotherapy or interferon. Interferon alpha-2a, 9 x 10(6) U sc daily, was administered together with doxorubicin 25 mg per m2 i.v. weekly, for 12 weeks. Response status was assessed by tumour measurements on clinical examination and thoracic CT scans before and after treatment. A partial response was observed in four patients (16%; 90% CI, 8-30%), 11 remained stable, while six had progressive disease. Four patients withdrew within the first month because of toxicity. The median survival of all patients was 11 months (95% CI, 3-19). Dose modification as a result of toxicity was required in all patients. Lethargy, weight loss, leukopenia and vomiting were the most common side effects. The combination of interferon-alpha and doxorubicin showed only modest activity and was associated with significant toxicity. It cannot be recommended in the treatment of malignant pleural mesothelioma.