The study will follow a conventional MTD design with patients recruited in cohorts of 3 patients, with criteria to expand to 6 patients. Enrolment for each cohort will begin when the required number of patients in the prior cohort have completed one 21-day cycle of study drug treatment at the current dose level without experiencing a DLT. Once the MTD has been determined, additional 10 patients will be treated at the MTD to further explore the toxicity of this dose, and its suitability for Phase II studies.