2 The technology
2.1 Sunitinib (Sutent, Pfizer) is one of a group of closely related tyrosine kinase inhibitors. It inhibits vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) receptors on cancer cells, vascular endothelial cells and pericytes. This reduces tumour cell proliferation and tumour blood vessel development. Sunitinib has a UK marketing authorisation for the treatment of people with unresectable and/or metastatic malignant gastrointestinal stromal tumour (GIST) after failure of imatinib mesilate treatment due to resistance or intolerance.
2.2 Sunitinib is contraindicated in people who have hypersensitivity to sunitinib malate or to any of the excipients. The summary of product characteristics (SPC) lists the following conditions that may be associated with sunitinib treatment: cardiovascular events, skin and tissue problems, gastrointestinal events, haemorrhage, hypertension, haematological problems, venous thromboembolic events, pulmonary embolism and hypothyroidism. For full details of side effects and contraindications, see the SPC.
2.3 Sunitinib is administered orally. The recommended dosage is 50 mg once daily, for 4 consecutive weeks, followed by a 2-week rest period (that is, a complete treatment cycle of 6 weeks). The dose may be adjusted in steps of 12.5 mg according to tolerability (within the dose range 25–75 mg). The price for a pack of 50-mg capsules (28 per pack) is £3138.80 (excluding VAT; 'British national formulary' [BNF] edition 56). The manufacturer of sunitinib has agreed a patient access scheme with the Department of Health for GIST, in which the first treatment cycle of sunitinib is free to the NHS. The Department of Health considered that this patient access scheme does not constitute an excessive administrative burden on the NHS. Costs of subsequent treatment cycles may vary in different settings because of negotiated procurement discounts.