Mesothelin-Targeted Immunotoxin LMB-100 in Combination With Tofacitinib in Persons With Previously Treated Pancreatic Adenocarcinoma, Cholangiocarcinoma and Other Mesothelin Expressing Solid Tumors

Background: The protein mesothelin is found on many kinds of tumors. The drug LMB-100 targets cancer cells that make this protein. Researchers want to see if LMB-100 combined with another drug can help people with these tumors. Objective: To find a safe dose of LMB-100 plus tofacitinib in people with pancreatic cancer, bile-duct cancer, and other solid tumors that make mesothelin. Eligibility: People ages 18 and older with pancreatic cancer, bile-duct cancer, or any other solid tumor with mesothelin that worsened after treatment or they could not receive standard treatment Design: Participants will be screened with: * Medical history * Tumor tissue sample. If they do not have a sample, they will have a biopsy. * Physical exam * Blood and heart tests * Scans and x-rays: They may have a dye injected for the scans. Participants will take the drugs in up to three 21-day cycles. They will take tofacitinib by mouth twice a day on days 1-10 of each cycle. They will have LMB-100 injected into the blood on days 4, 6, and 8 of every cycle. Patients that do not have a medi-port may need to have a central vein access line placed. Participants will take other drugs on the days they receive LMB-100. Participants will repeat screening tests during the study. They may have a biopsy at the start of the first 2 cycles. If participants must stop the study, they will have a safety visit 3-6 weeks after their last dose of the study drug. Some participants may then have visits every 6 weeks. After treatment, participants will be contacted about once a year. They will be asked about their cancer.