Mechanisms of action of new drugs in PTCL. Two naked antibodies targeting the CD52 and CCR4 molecules (alemtuzumab and mogamulizumab, respectively) have shown interesting potency in PTCL by mediating antibody-dependent cell-mediated and complement-dependent cytotoxicity. Romidepsin is an HDAC, which is able, among other mechanisms, to restore expression of proapoptotic genes. Pralatrexate is a dihydrofolate reductase inhibitor that impedes DNA synthesis. BV is an ADC combining an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a cytotoxic agent, the MMAE. MMAE is released upon internalization by CD30-expressing cells and disrupts microtubule polymerization. HDAC, histone deacetylase inhibitor.