8. Patients with reproductive potential (e.g., females menopausal for less than 1 year and not surgically sterilized) must practice two highly effective contraceptive measures for the duration of study drug therapy and for at least 90 days after completion of durvalumab monotherapy or for at least 180 days after completion of durvalumab/tremelimumab combination therapy. Female patients of childbearing potential must provide a negative pregnancy test (urine) prior to treatment initiation.