[Molecular-targeted therapies against adult T-cell leukemia]

Adult T-cell leukemia(ATL) is caused by infection with a human retrovirus, human T-cell leukemia virus type 1(HTLV-1). Since replication of HTLV-1 is generally suppressed in vivo, antiviral drugs targeting HTLV-1 replication steps are not effective in individuals chronically infected with HTLV-1. Once aggressive form ATL is developed in HTLV-1 carriers, their prognosis is poor even if they receive the intensive combined chemotherapy. Based on the characteristics of ATL cells, new drugs targeting ATL-specific cell surface markers and several signaling pathways, such as NF-kappaB have been developed. In addition, clinical observations show that ATL cells are highly immunogenic. Thus, establishment of the novel immune therapy is desired. In this review, we summarize recent progress in clinical and basic researches on new molecular-targeted therapies against this aggressive disease.