Genz-644282 will be administered as a 60-minute IV infusion. The initial dose of Genz-644282 will be 0.5 mg/m2 and will be administered once weekly for 3 consecutive weeks on Day 1, Day 8, and Day 15 of the 28 day cycle

Genz-644282 was tested against the PPTP in vitro panel (0.1 nM to 1 uM). In vitro, Genz-644282 demonstrated potent cytotoxic activity with a median IC(50) of 1.2 nM (range 0.2-21.9 nM). The ALL cell lines had lower relative IC50 values than the remaining cell lines (median of 0.4 nM versus 1.3 nM, p=0.034), while the rhabdomyosarcoma cell lines had higher relative IC50 values than the other PPTP cell lines (median of 2.5 nM versus 1.0 nM, p=0.047).