Anlotinib Plus PD-1 Inhibitor as 2nd-line Threapy in Patients With Metastatic Pancreatic Cancer

This research study is a Phase 2 clinical trial. It will test the efficiency and safety of an investigational drug of Anlotinib (a small molecular anti-VEGF TKI) with PD-1 inhibitor in second-line therapy with the goal of determining the OS of metastatic pancreatic adenocarcinoma. Subjects must have a stage 4 untreated metastatic pancreatic ductal cancer failed to first-line chemotherapy and meet all inclusion/exclusion criteria. Treatment consists of treatment with anlotinib 8-12 mg oral, day 1-14, and PD-1 inhibitor 200 mg iv, every 21 days each cycle. Treatment will be administered until untolerable toxicities or progression or subject death, or either the subject or sponsor discontinues the study.