N-563 is an analogue of deoxyspergualin with an immunostimulating activity,it promotes resistance to Candida albicans infection in mice. In vivo: The protective effect of the N-563 against C. albicans infection was investigated in normal and immunosuppressed mice. In normal mice, N-563 treatment at 10 mg/kg for 3 days prior to infection significantly prolonged the survival time. In immunosuppressed mice treated with a single dose of cyclophosphamide 4 days prior to infection, N-563 at 3 and 10 mg/kg for 3 days prior to infection also significantly prolonged the survival time of mice. In addition, it augmented the phagocytic activity of neutrophils and enhanced the delayed type hypersensitivity reaction against C. albicans. Coincidentally, N-563 appeared to protect against secondary infection with C. albicans in the delayed type hypersensitivity-positive mice.[1] N-563 was dissolved in physiological saline and filtered through a Millipore filter (0.22μm).[1]