 This is a phase I, multiple dose, dose escalation, open label, cohort study of three intravenous doses of Coxsackie virus A21 in patients with stage IV solid tumours. Prospective patients will attend the study centre for initial screening within 28 days prior to commencement of treatment. They will have the nature of the study and its procedures and risks fully explained. Patients must then sign an informed consent form giving permission for tumour testing before initial screening can be commenced. 