MinPAC is an open label, international, multicentre phase II trial that aims to evaluate the effects of Minnelide treatment in patients with refractory pancreatic cancer. Eligible patients will receive Minnelide until disease progression unless there is evidence of unacceptable toxicity or the patient requests to be withdrawn from the study treatment. Once disease progression is documented, patients will enter a follow up phase during which data will be collected on further disease and survival status. If patients are unable to attend hospital visits during the follow up period then data will be collected either via telephone or via national registries with the patient's consent. The efficacy of Minnelide will be assessed on CT/MRI scan images and tumour and/or blood samples collected at baseline, during treatment and on completion of treatment.