[Tax-targeted dendritic cell vaccine therapy for long-term remission of adult T-cell leukemia-lymphoma].

Abstract

Adult T-cell leukemia-lymphoma (ATL) is a highly aggressive peripheral T-cell neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1) infection occurring in approximately 5% of patients after prolonged latent period. ATL relapses within a short period despite its transient response to multiagent chemotherapy and the prognosis is extremely poor due to anticancer drug resistance and immunodeficiency. Although novel agents with different mechanisms, such as molecular targeted agents, have improved the prognosis, the number of cured patients remains limited. Hematopoietic stem cell transplantation resulted in long-term remission, whereas its indication is limited due to treatment-related mortality. As most ATL patients are of advanced age, development of a lesser toxic treatment is necessary. Therefore, we developed a novel therapeutic dendritic cell vaccine targeting the HTLV-1 Tax antigen. The safety profile has been confirmed in a pilot and phase I clinical studies, and a promising long-term clinical efficacy has also been obtained. This novel vaccine is a noninvasive, long-lasting therapy for ATL and can potentially be extended to different applications for low-grade ATL and high-risk HTLV-1 carriers.