Study of the Immunoresponse in Patients Treated With a Tyrosine Kinase Inhibitor

When cure is not longer possible, cancer patients enter the palliative phase. For many types of cancer several treatment options are available. The goal of this treatment is to prolong survival, but maintenance or even improvement of quality of life is of equal importance. The currently available systemic treatment options consist of conventional cytotoxic therapy, hormonal therapy, immunotherapy and the so-called targeted therapies. Combinations of these therapies are also being used. Targeted therapy concerns the application of a new class of drugs that are specifically directed against one or more well-defined molecular targets that are relevant for carcinogenesis, cell cycle regulation, tumour progression, metastasis, tumour angiogenesis and/or apoptosis. Today, the most successful drugs in this class are directed against the vascular endothelial growth factor (VEGF) and the epidermal growth factor receptor (EGFR). There is an explosive development ongoing in this field and many new drugs become available that have new targets or inhibit a combinations of targets. Meanwhile, targeted therapy has shown efficacy in many types of cancer and is registered for several indications. The toxicity profile of targeted therapies is still largely unknown, and the aetiology of many known side effects has not been clarified. At the moment, three targeted therapies that are directed against VEGF are registered and used in the Netherlands: Sunitinib (Sutent®) and Sorafenib (Nexavar ®) both oral drugs and Bevacizumab (Avastin®), an intravenously drug. Clinical experience and some mouse studies show that targeted therapies could have a negative effect on the immune response. This can be of great influence on patients who are treated with this type of drug. Especially because these drug will be used chronically and sometimes for years and infections can have a large influence on the health and quality of life of these patients.