Peripheral T-cell lymphoma (PTCL is a distinct and heterogeneous histopathologic subtype of non-Hodgkin lymphoma (NHL), accounting for ~10%. CHOP regimen has been widely used in PTCL patients even with unfavourable prognosis, with 5-year overall survival rate of 38.5%. Elderly patients seldom benefit from conventional CHOP regimen. A study showed that CR rate was only 18.1% in elderly patients (median age of 80 years old, ranging from 56 to 93 years old).

Azacitidine combined with romidepsin has been proved efficient in relasped or refractory PTCL, with CR rate of 55%. This prospective, open-label, single-arm study will evaluate the efficacy and safety of azacitidine in combination with Chidamide in treatment of newly diagnosed peripheral T-cell lymphoma unfit for conventional chemotherapy.