A phase 2 study of methotrexate, etoposide, dexamethasone, and pegaspargase chemotherapy for newly diagnosed, relapsed, or refractory extranodal natural killer/T‐cell lymphoma, nasal type: a multicenter trial in Northwest China

The nasal type of extranodal natural killer/T-cell lymphoma is a rare aggressive lymphoma with poor prognosis. To discover a successful treatment, we investigated the efficacy and safety of chemotherapy with methotrexate, etoposide, dexamethasone, and polyethylene glycol-asparaginase (MESA). Three cycles of MESA were administered to 46 patients with new or relapsed/refractory natural killer/T-cell lymphoma. Complete response after 3 treatment cycles was 43.5%, the overall response rate was 87%, and 2-year overall survival was 83.4%. Complete response was significantly better for newly diagnosed patients than for patients with relapsed/refractory disease. Patients with newly diagnosed disease had a significantly better overall response rate after 1, but not after 2 or 3 treatment cycles. Overall survival and progression-free survival did not differ over 2 years. Grade 1/2 toxicities were frequent, but MESA was associated with fewer grade 3/4 events or treatment-related deaths. These results will require confirmation in larger prospective trials.