NUC-1031 in Patients With Platinum-Resistant Ovarian Cancer

Inclusion Criteria: 1. Provision of signed written informed consent. 2. Original diagnosis and/or histological confirmation of high-grade serous, high-grade endometrioid, undifferentiated/unclassifiable epithelial ovarian, fallopian tube or primary peritoneal cancer. 3. Time from the last line of platinum-based chemotherapy of less than 6 months. 4. Received at least 3 prior chemotherapy-containing regimens. 5. Age ≥18 years. 6. Ability to comply with protocol requirements. 7. Patients are not of childbearing potential or they must agree to use a physical method of contraception. Exclusion Criteria: 1. Disease that progressed while receiving initial line of platinum-based chemotherapy. 2. Received fewer than 3 prior chemotherapy-containing regimens. 3. Prior therapy with single-agent gemcitabine. 4. Prior history of hypersensitivity to gemcitabine. 5. Prior chemotherapy, radiation (other than short cycle of radiation to reduce bone pain), treatment with a VEGF inhibitor, PARP inhibitor or immunotherapy within 21 days of first receipt of study drug. Hormone therapy within 14 days of first receipt of study drug. 6. Residual side effects from chemotherapy or radiation, which have not gotten better except for nerve pain or tingling or hair loss. 7. Patients who have a history of another type of cancer diagnosed within the past 5 years, with the exception of adequately treated non-melanoma skin cancer curatively treated cervical cancer or ductal carcinoma in situ (DCIS) of the breast. 8. Presence of an serious illness, uncontrolled illness, or active infection requiring IV antibiotics. 9. Presence of any serious illnesses, serious medical conditions, serious medical history, active bacterial or viral infections including hepatitis B or C, or known to be HIV positive. 10. Currently pregnant, lactating or breastfeeding. 11. History of blocked intestines because of ovarian cancer, unless fully resolved.