Patients will be treated with CXD101 administered orally starting at 1mg twice a day (ie: 2mg/day). Dose escalation will proceed according to a standard 3+3 phase 1 scheme. Adverse experiences will be evaluated according to the NCI Common Terminology Criteria for Adverse Events, version 4.0. Dose escalation will continue until dose limiting toxicity is encountered in >1/3rd of patients at any dose level. The dose level below this will be determined to be the maximum tolerated dose. Patients will be treated, at the discretion of the Principal Investigator, until disease progression, unacceptable toxicity or the withdrawal of consent. At the maximum tolerated dose a further 20 patients, defined by tumour HR23B expression will be enrolled.