Complete regression of AIDS-KS tumors by intratumoral administration of IL-13 toxin.

The nude mice (n = 4 per group) with established KS Y-1 tumors received 30 μL of IL-13 toxin (A) slowly into all quadrants of tumor (7.5 μL per quadrant) by 26-guage syringe on day 4, 6, and 8. The control animals received excipient only. One animal died on day 6 in the 250 μg/kg dose group. (B) The similar doses as of Figure 6a, but with a schedule of daily injections were administered on day 4 through 8. Because some mice in the treatment groups obtained CR, the error bars in mean tumor size were large and are not shown. The mean values for 0, 50, and 100 μg/kg doses were 345 ± 91, 179 ± 72, and 25 ± 5, respectively, on day 36. The arrows point to the days of treatments. (C) Large KS Y-1 tumors were injected with 2 cycles of 5 injections of IL-13 toxin as shown by arrows on the x-axis. Each group had 7 mice. (D) Established KS-imm xenografts received 5 daily injections of IL-13 toxin beginning on day 4.