Potent ITK/BTK Inhibitor Ibrutinib Is Effective for the Treatment of Experimental Visceral Leishmaniasis Caused by Leishmania donovani.

Background New drugs are needed for leishmaniasis because current treatments such as pentavalent antimonials are toxic and require prolonged administration, leading to poor patient compliance. Ibrutinib is an anticancer drug known to modulate T-helper type 1 (Th1)/Th2 responses and has the potential to regulate immunity against infectious disease. Methods In this study, we evaluated the efficacy of oral ibrutinib as a host-targeted treatment for visceral leishmaniasis (VL) caused by Leishmania donovani using an experimental mouse model. Results We found that oral ibrutinib was significantly more effective than the pentavalent antimonial sodium stibogluconate (70 mg/kg) for the treatment of VL caused by L. donovani. Ibrutinib treatment increased the number of interleukin 4– and interferon γ–producing natural killer T cells in the liver and spleen and enhanced granuloma formation in the liver. Further, ibrutinib treatment reduced the influx of Ly6C^hi inflammatory monocytes, which mediate susceptibility to L. donovani. Finally, ibrutinib treatment was associated with the increased production of the cytokines interferon γ, tumor necrosis factor α, interleukin 4, and interleukin 13 in the liver and spleen, which are associated with protection against L. donovani. Conclusions Our findings show that oral ibrutinib is highly effective for the treatment of VL caused by L. donovani and mediates its antileishmanial activity by promoting host immunity. Therefore, ibrutinib could be a novel host-targeted drug for the treatment of VL. [ABSTRACT FROM AUTHOR]