Relapsed and refractory peripheral T-cell lymphoma; treatment, challenges and future perspectives.

Peripheral T-cell lymphomas (PTCL) comprise a heterogeneous group of 15 different neoplasms in adults. In Europe and North America, PTCL not otherwise specified (PTCL NOS), nodal T follicular helper lymphoma, angioimmunoblastic type (nTFHL-AI), and anaplastic large cell lymphoma (ALCL) either anaplastic lymphoma kinase (ALK) positive (+) or negative (-) are the most prevalent PTCLs. Relapsed or refractory disease (R/R) is common in PTCL and its management is challenging. Despite response rates and prognoses being disease specific, the outcome of R/R PTCL is dismal except for R/R ALK+ ALCL. Populations in R/R PTCL studies have mostly been heterogeneous and encompassing several entities. While there are many treatment options for R/R PTCL such as salvage chemotherapy, autologous or allogeneic stem cell transplant, epigenetic drugs, monoclonal antibodies, and small molecules, responses are limited and few are curative. Here we review the management of R/R PTCL, focusing on ALCL, nTFHL, and PTCL NOS.