A Phase II Study of Methotrexate, Etoposide, Dexamethasone and Pegaspargase Sandwiched with Radiotherapy in the Treatment of Newly Diagnosed, Stage IE to IIE Extranodal Natural-Killer/T-Cell Lymphoma, Nasal-Type

BACKGROUND A phase II study of methotrexate, etoposide, dexamethasone, and pegaspargase (MESA) sandwiched with radiotherapy for newly diagnosed, stage IE-IIE extranodal natural-killer/T-cell lymphoma, nasal-type (ENKTL) was conducted to explore its clinical efficacy and safety, as well as novel serum biomarkers upon anti-metabolic treatment. METHODS Four cycles of MESA sandwiched with radiotherapy were administered. The primary end point was the overall response rate (ORR). Serum metabolomic profiles were assessed by liquid chromatography-mass spectrometry, with specific metabolites quantified by targeted metabolic analysis. FINDINGS Forty patients were enrolled and the ORR was 92.1% (95%CI, 83.1%-100.0%). The 2-year progression-free survival (PFS) rate was 89.1% and overall survival (OS) rate was 92.0%. Grade 3/4 non-hematologic and hematologic toxicities were observed in 17 (42.5%) and 26 patients (65·0%) during chemotherapy, and in 9 (22.5%) and 0 (0.0%) patients during radiotherapy, respectively. Fifty-six significantly decreased and 59 increased metabolites were identified in ENKTL, as compared to healthy volunteers. A predictive principal components analysis model of asparaginase-associated metabolites, asparaginase-associated metabolic score (AspM), was established, including alanine, aspartate, glutamate, and succinic acid. Patients with high AspM score displayed superior survival and prognostic significance of AspM was validated in a historical cohort of early and advanced-stage ENKTL treated with asparaginase-based regimens. Multivariate analysis confirmed AspM as a prognostic score independent of PINK and PINK combined with Epstein-Barr virus DNA. INTERPRETATION MESA sandwiched with radiotherapy is an effective and safe regimen for early-stage ENKTL. AspM score may be a promising prognostic index of serum metabolites in addition to clinical prognostic index in ENKTL.