Enhancing CAR-T Cell Therapy Efficacy in B-cell Lymphoma Via Chidamide and PD-1 Inhibitor Combination.

B-cell non-Hodgkin lymphoma (B-NHL) is one of the most common malignancies in China, with approximately 100,000 new cases diagnosed annually. Although immunochemotherapy, novel small-molecule targeted agents, and hematopoietic stem cell transplantation have significantly improved outcomes for patients with B-cell malignancies, nearly half of patients still experience drug resistance and relapse. In high-risk aggressive B-cell lymphoma, the 5-year survival rate remains around 50%. Previous clinical guidelines recommended autologous hematopoietic stem cell transplantation as first-line consolidation therapy for high-risk patients; however, multiple studies have demonstrated that even after autologous transplantation, nearly half of these patients relapse and succumb to the disease. Chimeric antigen receptor T (CAR-T) cell therapy has achieved objective response rates of approximately 50% in relapsed/refractory lymphoma, particularly in B-cell subtypes. Nevertheless, limitations such as tumor immune antigen escape, immunosuppressive effects of the tumor microenvironment (TME) on CAR-T cells, and T-cell exhaustion continue to restrict the durability and efficacy of CAR-T-mediated cytotoxicity. This study evaluates the incorporation of chidamide (an HDAC inhibitor) combined with a PD-1 inhibitor as maintenance therapy following CAR-T cell immunotherapy in patients with relapsed/refractory high-risk aggressive B-cell lymphoma. By implementing an "early intervention" strategy-prompt administration of CAR-T cell therapy after induction treatment for relapsed/refractory high-risk aggressive B-cell lymphoma-and subsequent maintenance with chidamide plus a PD-1 inhibitor, the approach aims to reduce relapse rates and improve overall survival. These strategies are intended to address the current unmet clinical need for improved outcomes in relapsed/refractory high-risk aggressive B-cell lymphoma, where prognosis remains poor despite existing therapies.