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.