This study tests a new virus called CF33-CD19 with a drug called blinatumomab to see if they work together to treat advanced or spreading (metastatic) tumors. A tumor is a lump of abnormal cells, and metastatic means it has spread to other body parts. The study, called OASIS, is open-label, meaning participants will know what treatment they receive. The study will check if the treatment is safe and tolerable, which means it won’t cause serious side effects and is not too hard to manage. People can join if they are 18 or older, have a solid tumor that has spread, and have tried at least two treatments before without success. Participants will get different treatments based on the study plan, with treatments occurring on certain days in cycles (like Day 1 and Day 8). If you have any serious conditions like certain heart or lung diseases, or have had certain kinds of treatment before, you might not be able to join. Before joining, make sure you can visit the study places, follow the treatment plan, and do required tests.

• Study length: Participates will undergo treatment cycles.
• Visit frequency: Visits needed for scheduled treatment days.
• Eligibility: Must have tried at least two treatments before.