The purpose of this study is to determine the response rate to the combination of doxorubicin and valproate acid in patients with MM failing after at least one previous chemotherapy regimen including platinum derivatives .

Inclusion Criteria:

• Histological diagnosis of malignant mesothelioma
• Unresectable or inoperable malignant mesothelioma failing after at least one prior chemotherapy regimen including platinum derivatives (cisplatin or carboplatin)
• At least one evaluable or measurable CT-lesion
• Availability for participating in the detailed follow-up of the protocol
• Signed informed consent

Exclusion Criteria:

• Patients who are candidates for surgery with curative intent
• Patient who were previously treated with anthracyclin derivatives
• Performance status < 60 on the Karnofsky scale
• A history of prior malignant tumour, except non-melanoma skin cancer or in situ carcinoma of the cervix and cured malignant tumour (more than 5-year disease free interval)
• A history of prior HIV infection
• Polynuclear cells < 2,000/mm³
• Platelet cells < 100,000/mm³
• Abnormal coagulation tests (aPTT, PTT, prothrombin time) and/or decreased fibrinogen
• Serum bilirubin >1.5 mg/100 ml
• Transaminases more than twice the normal range
• Serum creatinine > 1.5 mg/100 ml
• Recent myocardial infarction (less than 3 months prior to date of diagnosis)
• Congestive cardiac failure (ejectional fraction of the left ventricle < 50%) or uncontrolled cardiac arrhythmia
• Uncontrolled infectious disease
• Active epilepsy needing a specific treatment
• Concomitant treatment with IMAO, carbamazepine, mefloquine, phenobarbital, primidone, phenytoïn, lamotrigine, zidovudine
• Pregnancy or refusal to use active contraception
• A known allergy to valproate acid and/or doxorubicin
• Serious medical or psychological factors which may prevent adherence to the treatment schedule