Combination of anti-PD-1 antibody with P-GEMOX as apotentially effective immunochemotherapy for advancednatural killer/T cell lymphoma

Advanced natural killer/T cell lymphoma(NKTL)has demonstrated poor prognosis with currently available therapies.Here,we report the efficacy of anti-programmed death 1(PD-1)antibody with the P-GEMOX(pegaspargase,gemcitabine,and oxaliplatin)regimen in advanced NKTL.Nine patients underwent six 21-day cycles of anti-PD-1 antibody(day 1),pegaspargase 2000 U/m^(2)(day 1),gemcitabine 1 g/m^(2)(days 1 and 8)and oxaliplatin 130 mg/m^(2)(day 1),followed by anti-PD-1 antibody maintenance every 3 weeks.Programmed death-ligand 1(PD-L1)expression and genetic alterations were determined in paraffin-embedded pretreatment tissue samples using immunohistochemistry and next-generation sequencing(NGS)analysis.Responses were assessed using ^(18)F-fluorodeoxyglucose positron emission tomography(^(18)FDG-PET)and computed tomography or magnetic resonance imaging.Eight patients exhibited significant responses,comprising of seven complete remissions and one partial remission(overall response rate:88.9%).After a median follow-up of 10.6 months,6/9 patients(66.7%)remained in complete remission.The most common grade 3/4 adverse events were anemia(33.3%),neutropenia(33.3%),and thrombocytopenia(33.3%);all of which were manageable and resolved.Immunochemotherapy produced a high response rate in patients with positive PD-L1 expression(5/6,83.3%).NGS analysis suggested that STAT3/JAK3/PD-L1 alterations and ARID1A mutation were associated with immunochemotherapy efficacy.Mutation in DDX3X and alteration in epigenetic modifiers of KMT2D,TET2,and BCORL1 might indicate a poor response to immunochemotherapy.In conclusion,the anti-PD-1 antibody plus P-GEMOX regimen demonstrated promising efficacy in advanced NKTL.PD-L1 expression combined with specific genetic alterations could be used as potential biomarkers to predict therapeutic responses to immunochemotherapy.