Evolution of hematocrit during treatment by SU5416.

The evolution of hematocrit in the 3 enrolled VHL patients is shown: patient 1 (female; open circle), patient 2 (female; open square), patient 3 (male; open triangle). SU5416 administration was not interrupted, and polycythemia was treated by bloodletting (arrows) with good outcome and without recurrence up to the sixth month of treatment. Normal maximal values of hematocrit in males and females, respectively, are indicated by gray horizontal lines.