Azacitidine and Rituximab-GDP Immunochemotherapy in Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma

This phase II clinical trial aims at evaluating the efficacy and safety of azacitidine followed by rituximab-GDP immunochemotherapy in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). This study is designed with the expectation of correction of aberrant hypermethylation of tumor suppressor genes by preceding use of low dose azacitidine thereby re-sensitizing chemosensitivity of tumor cells. Patients who were treated with from 1 to 4 lines of prior therapies for relapsed/refractory DLBCL wee eligible. Planned initial doses of the current regimen are as follows; azacitidine S.C 25 mg/m2 D1,2,3,4,5 rituximab I.V. 375 mg/m2 D8 gemcitabine I.V. 1,000 mg/m2, D8,15 dexamethasone I.V. or P.O. 40 mg D8,9,10,11 cisplatin 70 mg/m2 I.V. D8 Patients will be treated every 21 days as one cycle, and up to 6 cycles of treatment will be conducted. Especially, first 3\~6 patients will be regarded as 'lead-in safety cohort' and their safety will be reviewed by an independent data and safety monitoring board (DSMB). The primary endpoint of this study is objective response rate according to the Lugano response criteria for non-Hodgkin lymphoma, and secondary endpoints are safety, complete response, progression-free survival, and overall survival.