Pralatrexate Combined With Chidamide Bridging Allogeneic HSCT 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