Mogamulizumab (Mog), a humanized anti-CC chemokine receptor 4 (CCR4) mAb that mediates antibody-dependent cellular cytotoxicity (ADCC) using FcγR IIIa (CD16)-expressing effector cells, has recently been approved for treatment of CCR4-positive adult T-cell leukemia (ATL) in Japan.
Previously, we and others have shown that the majority of ATL cases are strongly positive for CCR4, which may explain the frequent skin invasion of ATL.
Galectin-9 as a Predictive Marker for the Onset of Immune-Related Adverse Effects Associated with Anti-CCR4 MoAb Therapy in Patients with Adult T Cell Leukemia.
Although the anti-CCR4 antibody mogamulizumab (moga) shows striking antitumor activity against adult T cell leukemia (ATL), it can also cause fatal immunological pathology such as severe skin rash and graft-versus-host disease, which might be attributed to depletion of CCR4<sup>+</sup> regulatory T cells.