Allogeneic transplantation and cellular therapies in cutaneous T-cell lymphoma

IntroductionMycosis fungoides (MF) and Sezary syndrome (SS) are the most common types of cutaneous T-cell lymphoma. Although many available treatments offer temporary disease control, allogeneic hematopoietic stem cell transplant (allo-HSCT) is the only curative treatment option for advanced stage MF and SS. CAR T-cell therapy is a promising new avenue for treatment.Areas coveredIn this review, we discuss the evidence supporting the use of allo-HSCT for the treatment of MF/SS, including disease status at the time of transplant, conditioning regimen, total body irradiation (TBI), and donor lymphocyte infusion (DLI). We also address the potential role for CAR T-cell therapy in CTCL.Expert opinionAllo-HSCT is an effective treatment for patients with advanced MF and SS. However, significant research is required to determine optimal treatment protocols. Data support the use of reduced-intensity conditioning regimens and suggests that the use of TBI for debulking of skin disease may result in more durable remissions. Donor lymphocyte infusions (DLI) appear to be particularly effective in inducing complete remission in MF/SS patients with relapsed or residual disease. Challenges with CAR-T therapies in T-cell lymphoma include T-cell fratricide due to shared antigens on malignant and nonmalignant T-cells, penetrance into the skin compartment, and CAR-T cell persistence.