Adoption of a long term in vitro bone model to facilitate investigations into cancer dormancy and bone metastasis

In 2014 there were over 41,000 new cases of colorectal cancer (CRC) in the UK and nearly 16,000 deaths from the disease, making it the second commonest cause of cancer death. Previous trials have shown that tumours with certain genetic problems identified in the laboratory, known as microsatellite instability (MSI) respond well to immunotherapy drugs. However, most people with colorectal cancer will not have this particular genetic problem in their tumour, known as microsatellite stablility (MSS) and these drugs do not work as well for these patients. An immunohistochemistry test has been developed to assess the level of a molecule called Class II in colorectal tumours. We think that MSS bowel tumours with stronger levels of Class II molecules respond better to nivolumab, in the same way that MSI tumours respond. We estimate that about 1 in 10 people tested will have a high level of the class II molecule. The purpose of this trial is to see if an immunotherapy drug called nivolumab is an effective treatment for this group of patients. The trial aims to find out if nivolumab provides a durable clinical benefit in halting further growth or spread of the cancer for at least 6 months and if it is effective enough to justify further testing in patients with MSS colorectal cancer with strong class II levels. To look at whether the cancer is responsive to nivolumab, computed tomography (CT) scans will be used to look at the tumour(s) and measure if they are getting bigger or smaller. This is a single arm phase II trial, with a total duration of 4 years (18 months recruitment, two years treatment and 5 years follow up of patients)