This study is testing two different drugs, KITE-753 and axicabtagene ciloleucel (also called axi-cel), to see how well they work in treating a type of cancer called large B-cell lymphoma (LBCL). LBCL is a blood cancer that can return or resist treatment after the first round of therapy. The study will help determine which drug is more effective for adults whose cancer has come back or hasn't responded to initial treatments. **Important Points:** - **Duration and Visits:** The study will require multiple visits over a period of time, though the exact number of visits is not specified. - **Treatments:** Participants will receive one of the two drugs being studied. - **Risks and Eligibility:** Participants should not have had certain previous treatments and must meet specific health requirements to join. If you think you might qualify and are interested, talking to your doctor could be a great first step to learn more about participating. **Study Requirements:** - Must have one measurable lesion. - Previous cancer treatments with specific drugs are required. - Must not have certain health conditions or histories that could interfere with the study.