This study evaluates the efficacy and safety of Chidamide plus CHOP regimen for de novo PTCL patients.

After enrollment, patients in this study will be given Chidamide, Cyclophosphamide, Epirubicin, Vincristine and Prednisone, and the efficacy and safety of this regimen are then evaluated.

Inclusion Criteria:

1. Pathologically diagnosed as peripheral T cell lymphoma (PTCL) according to WHO 2008 classification criteria（NK/T cell lymphoma, ALK positive anaplastic large cell lymphoma and granuloma fungoides excluded）;
2. De novo peripheral T cell lymphoma patients;
3. Age 18-70 years old;
4. ECOG≤2；
5. Female patients not in lactation nor pregnancy, and no intention to concept during the study and 12 months thereafter. Male patients agree not to impregnate his partner during the study and 12 months thereafter;
6. The patient should have evaluable foci (lymphnodes with diameter≥1.0cm, or evaluable skin foci);
7. Willing to sign a written consent.

Exclusion Criteria:

1. T lymphoblast lymphoma;
2. Bone marrow infiltrated with lymphoma cell ≥25%；
3. NT/T cell lymphoma;
4. Granuloma fungoides;
5. Severe impaired liver/ renal function (ALT, Bilirubin or creatinine >3 times the normal maximum);
6. Uncontrolled infection;
7. Organic cardiopathy with clinical manifestation or impaired cardiac function (NYHA ≥ level 2);
8. With other tumors;
9. With other condition that cause the patient unable to sign the written consent;

All the data would be available at the First Affiliated Hospital after the study is finished

From the time of study finish