Dose Escalation and Expansion Study of FLX475 Monotherapy and in Combination With Pembrolizumab

Inclusion Criteria: * Documented advanced or metastatic cancer ineligible for standard therapies with one of the following histologies * Dose Escalation: non-small cell lung cancer, head and neck squamous cell carcinoma, nasopharyngeal carcinoma, metastatic triple negative breast cancer, urothelial carcinoma, gastric cancer, esophageal carcinoma, cervical cancer, classical Hodgkin lymphoma * Dose Expansion: nasopharyngeal carcinoma, lymphoma, head and neck squamous cell carcinoma, cervical cancer, non-small cell lung cancer, triple-negative breast cancer * Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1 * Evaluable disease at baseline (at least one measurable target lesion by imaging for expansion cohorts) * Tumor available for biopsy Exclusion Criteria: * History of allergy or severe hypersensitivity to biologic agents * History of Grade 3-4 immune-related adverse events leading to discontinuation of prior immuno-oncology treatment * Active autoimmune disease or serious autoimmune disease within past 2 years requiring systemic therapy * History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, (non-infectious) pneumonitis that required steroids, or symptoms of active pneumonitis * Prior allogeneic hematopoietic stem cell transplant within 5 years, or prior allogeneic organ transplant * Active graft-versus-host disease