Chidamide Maintenance for MRD-Positive Double-Expressor DLBCL in First Complete Remission

This is a prospective, multicenter, single-arm, open-label phase 2 study designed to evaluate the efficacy and safety of chidamide maintenance in adults with newly diagnosed double-expressor diffuse large B-cell lymphoma (DLBCL) who achieve complete response after induction therapy but remain ctDNA minimal residual disease (MRD)-positive. Eligible participants will receive oral chidamide 20 mg on Days 1, 4, 8, and 11 of each 21-day cycle. ctDNA MRD will be assessed every 12 weeks. Treatment will continue until two consecutive MRD-negative assessments, disease progression, intolerable toxicity, withdrawal of consent, or completion of 2 years of maintenance. The primary objectives are to evaluate ctDNA MRD negativity and 2-year progression-free survival. Secondary objectives include event-free survival, overall survival, and safety.