LEAP regimen

This is a randomized, open-label, prospective, multicenter phase III superiority study in patients with newly diagnosed stage IV extranodal NK/T-cell lymphoma. The study compares two frontline induction strategies followed by consolidation with autologous hematopoietic stem cell transplantation in patients who achieve a protocol-defined strict complete remission. Eligible participants will be randomized 1:1 to Arm A or Arm B, stratified by three-level PINK-E risk category. Arm A consists of one cycle of GELAD induction followed by three cycles of MEDA chemotherapy. Participants who achieve strict complete remission after key response assessment will proceed to autologous hematopoietic stem cell transplantation consolidation. Arm B consists of four cycles of LEAP induction with sintilimab, pegaspargase, and anlotinib. Participants who achieve strict complete remission will receive high-dose methotrexate CNS-directed consolidation followed by autologous hematopoietic stem cell transplantation consolidation if eligible. The primary endpoint is event-free survival within 24 months after randomization. Secondary endpoints include progression-free survival, overall survival, overall response rate, complete remission rate, strict complete remission rate, autologous hematopoietic stem cell transplantation completion rate, cumulative incidence of relapse, grade 3 or higher adverse events, treatment discontinuation, treatment-related mortality, and plasma EBV-DNA clearance dynamics.