Bijwerkingen van de tyrosinekinaseremmer sunitinib, een nieuw middel voor de behandeling van gemetastaseerd niercelcarcinoom

Three patients with advanced renal-cell cancer were treated with sunitinib 50 mg daily for 4 weeks followed by a rest period of 2 weeks because of progressive disease. The first patient developed stomatitis and a painful blister on his foot. Complaints disappeared after temporary discontinuation of treatment. Re-treatment at a lower dosage was successful until disease progression. The second patient developed skin discolouration, fatigue, fever and diarrhoea. After treatment was interrupted shortly, these symptoms disappeared and sunitinib was recommenced at a lower dosage. The patient went on to develop stomatitis, thrombocytopenia and hypertension (treated with amlodipine). She subsequently had hand-foot syndrome. She died due to brain metastases. In the third patient symptoms of disease returned during the rest period, because of which he received a reduced dosage of sunitinib on a continuous base. He developed diarrhoea which disappeared after a short interruption of the drug. Sunitinib has been approved for the treatment of advanced renal-cell cancer and imatinib-resistant gastro-intestinal stromal tumours. This novel targeting molecule is a tyrosine-kinase inhibitor of vascular endothelial growth-factor receptors, platelet-derived growth-factor receptors and c-Kit. It can induce adverse events that differ from those observed in treatment with conventional cytotoxic agents. The adverse effects are reduced by lowering the dosage and in the rest period within the treatment cycle.