A Study of the CD73 Inhibitor LY3475070 Alone or in Combination With Pembrolizumab in Participants With Advanced Cancer

Inclusion Criteria: * Participants must have certain types of cancer such as breast cancer, pancreatic cancer, lung cancer, kidney cancer, skin cancer (melanoma), prostate cancer, and ovarian cancer * Participants must have stopped other forms of treatment for the cancer * In the expansion cohorts participants must be able and willing to provide a sample of the tumor before beginning treatment and a sample during the treatment. For certain tumor types, the result of a test on the tumor sample may exclude the participant from the study * Participants must not be pregnant, and must agree to use birth control * Participants must have progressed through or be intolerant to therapies with known clinical benefit Exclusion Criteria: * Participants must not have a current untreated tuberculosis, lung disease, heart disease, uncontrolled HIV, autoimmune disease, active hepatitis B or C virus infection or using corticosteroids * Participant must not have cancer that has spread to the brain * Participant must not have received a vaccine within the last 30 days * Participant must not have had bowel obstruction within the last 6 months, or intestinal surgery * Participant must not have an infection that is currently being treated