Induction with MEDA regimen and consolidation with Auto‐HSCT for stage IV NKTCL patients: A prospective multicenter study

Abstract Optimal treatment strategies for natural killer/T‐cell lymphoma (NKTCL) patients with stage IV disease have not been well defined. In this prospective phase 2 study, we evaluated the treatment using MEDA (methotrexate, etoposide, dexamethasone and pegaspargase) as induction chemotherapy and autologous hematopoietic stem cell transplantation (Auto‐HSCT) for consolidation. Patients with stage IV disease without prior L‐asparaginase‐based chemotherapy were eligible. Four cycles of MEDA were administered as induction treatment. Patients with complete response (CR, necessary to have complete metabolic remission of PET/CT, negative plasma EBV‐DNA and negative EBER staining of bone marrow biopsy tissue) were consolidated by Auto‐HSCT. A total of 53 patients were enrolled. The overall response (OR) rate and CR rate after four cycles of MEDA chemotherapy were 75.5% and 56.6%, respectively. Among them, 25 patients underwent Auto‐HSCT. The 4‐year overall survival (OS) rate and progression‐free survival (PFS) rate were 58.0% (95% CI, 43.4%‐70.0%) and 43.4% (95% CI, 29.9%‐56.1%), respectively. Patients who underwent Auto‐HSCT had a 4‐year OS rate of 92.0% (95% CI, 71.6%‐97.9%) and a 4‐year PFS rate of 80.0% (95% CI, 58.4%‐91.1%). Grade 3/4 neutropenia and thrombocytopenia occurred in 28.3% and 17.0% of the patients, respectively. MEDA chemotherapy is an effective induction regimen with reduced grade 3/4 hematological toxicities for stage IV NKTCL. Consolidation with Auto‐HSCT can be considered as a potential approach to improve the long‐term survival of CR patients after induction treatment.