This is a multicenter, prospective study of Pralatrexate combined with Chidamide bridging Allogeneic Hematopoietic Stem Cell Transplantation for Refractory/Relapsed Peripheral T-cell Lymphoma

Inclusion Criteria:

• Patients fully understand the study, voluntarily participate in and sign on the informed consent;
• Diagnosed by histopathology Peripheral T-cell lymphoma;
• ECOG PS score 0 or 1;
• Relapsed or Refractory Peripheral T Cell Lymphoma；
• According to the 2014 version of the Lugano criteria for lymphoma, there must be at least one CT/MRI measurable lesion (measurable lymph node diameter>1.5cm; measurable extranodal lesion diameter>1.0cm)；
• Provided a written pathological/histological diagnosis report during the screening period and agreed to provide tumor tissue sections or tumor/lymph node tissue specimens for testing at the central laboratory;
• Expected survival at least 12 weeks；
• Agreed to receive treatment with Pralatrexate

Exclusion Criteria:

• NK/T-cell lymphoma;
• Achieving CR or PR after induction chemotherapies without relapse;
• Dysfunction of vital organs;
• Serious history of autoimmune diseases and immunodeficiency, including: positive for human immunodeficiency virus (HIV) antibodies; Or other acquired or congenital immunodeficiency diseases; Or have a history of organ transplantation;
• Unwilling to accept allogeneic hematopoietic stem cell transplantation;
• Undergoing other clinical studies within a month;
• Without donor for transplantation;
• Allergies to similar drugs and excipients of the research drug