Immune evasion and current immunotherapy strategies in mycosis fungoides (MF) and Sézary syndrome (SS)

Mycosis fungoides (MF) and Sézary syndrome (SS) are two well-characterized skin limited and leukemic subtypes of cutaneous T-cell lymphoma (CTCL), respectively. Progressive global immune dysfunction and a multitude of specific immunological abnormalities have long been recognized as features of MF and SS. Therefore, a variety of immune-based therapies have been explored and used in the clinic for decades in the attempt to restore the immune imbalance in these malignancies. With recent advances in the development of novel immunotherapies in cancer treatment, new treatment modalities have emerged to complement the existing repertoire. Herein, we provide a comprehensive review of immune evasive mechanisms in MF/SS and summarize the established and emerging immunotherapies for these malignancies. We explain the underlying mechanisms of these immune-based therapies and derive recommendation from results of major clinical trials.