RS 0481 modulates the immune response and rebuilds lymphocyte populations damaged by tumor growth in animals.

In the mouse model, RS-0481 was administered at dose ranges tested of 0.1, 1, and 10 mg/kg, all of which were given by the oral route to X5563 tumor-burdened mice. The dosing schedule consisted of 5 consecutive days on days 1-5 or days 12-16 after tumor inoculation. It was found that all of these doses significantly enhanced anti-tumor immune responses, including tumor-specific cytotoxic T-lymphocytes (CTLs), delayed-type hypersensitivity T-cells (TDTHs), and non-specific lymphokine-activated killer cell-like cell responses. Also, RS-0481 enhanced the tumor suppressor effect of macrophages from tumor-burdened mice, but had no effect on macrophages from normal mice. [1]