Hematologic response to forodesine. (A) Patient no. 2 had decrease in absolute prolymphocyte count with course 1 (solid) and course 2 (dashed) in the time course shown. (B) Patient no. 4 cleared circulating T cells by day 10. (C) Patient no. 5 had cytoreduction with each course of forodesine with absolute prolymphocyte counts plotted for course 1 (•), course 2 (▵), course 3 (□), course 4 (♦).