Axicabtagene Ciloleucel for Consolidation After First-line Treatment of High-risk Large B-cell Lymphoma

The goal of this clinical trial is to learn if Axicabtagene Ciloleucel (axi-cel) works for consolidation after first-line treatment of high-risk Large B-cell Lymphoma (LBCL). It will also learn about the safety of axi-cel treatment. The main questions it aims to answer are: * Does axi-cel treatment result in prolonged clinical benefit to patients with high-risk LBCL after first-line treatment? * What medical problems do participants have when receiving axi-cel treatment? In this investigator-initiated, single-arm clinical trial, participants will: * Receive atezolizumab treatment at 2.0×10\^6 cells/Kg as a one-time therapy. * Visit the clinic as instructed for checkups and tests.