Multicenter, open phase 2 study on patients with malignant mesothelioma. Standardly, 4 to 6 cycles of palliative chemotherapy, platinum in combination with pemetrexed, are given. Despite of this treatment, median survival is poor (9-12 months). By combining conventional cytotoxic agents with a novel agent, hopefully treatment and survival can be approved. Cetuximab or Erbitux is a monoclonal antibody against the EGFR (Epidermal Growth Factor Receptor). By blocking the receptor, it interferes with cel growth and division. Most mesothelioma show a strong expression of the EGFR protein. Apart from that, Cetuximab also has antibody-dependent cell-mediated cytotoxicity (ADCC).

In this trial, patients will be treated with standard chemotherapy, combined with Cetuximab weekly. After a maximum of 6 cycles of chemotherapy, administration of Cetuximab will be continued until disease progression. Every 6 weeks, a CT scan will be done to evaluate therapy. Most common side effect of Cetuximab is acneiform rash.

The translation research program consists of the determination of EGFR- and K-Ras mutations on the tumor tissue and the correlation with outcome.

In the first part of the trial, 18 patients will be included. After a positive interim analysis, a total of 43 patients will be included.

Inclusion Criteria:

• Histologically proven malignant pleural mesothelioma, epitheloid subtype
• Recurrent after radical surgery or disease not considered suitable for radical treatment
• EGFR IHC + as assessed by DAKO kit with at least 1% of cells showing staining
• Performance status WHO 0 or 1
• Life expectancy > 12 weeks
• Weight loss < 10% in last 3 months
• Adequate bone marrow reserve, renal and hepatic function
• Measurable disease (modified RECIST)
• No prior chemotherapy
• No prior or other malignancies, except if longer than 5 yrs ago and adequately treated or basocellular skin or in situ cervical cancer
• No uncontrolled infection
• Written informed consent.
• Male/Female
• > 18 years

Exclusion Criteria:

• Evidence of brain or leptomeningeal metastases
• Patients who are unable to interrupt aspirin, other nonsteroidal anti-inflammatory drugs for a 5-day period starting 2 days before administration of pemetrexed (8-day period for long acting agents such as piroxicam)
• Patients that cannot be treated with folic acid and vitamin B 12
• Patients that cannot be treated with dexamethasone.
• Presence of clinically detectable (by physical examination) third-space fluid collections, for example ascites of pleural effusions that cannot be controlled by drainage or other procedures prior to the study entry.
• Use of investigational drugs