 4. Conflict of Interest Participants may be recruited to the study by those involved in their prior clinical care. Investigators do not expect conflict of interest between research and healthcare duties for a number of reasons: participants must give their full informed consent before entering the study, specifically regarding the unknown efficacy of the study drug. Those participants who do not continue in the study will maintain a relationship with the clinical team if required for symptom control. At the end of the study, participants will be able to access the results if they wish, through the Royal Marsden Website. They will also be sent a written summary of the results if they indicate this. 