Patients randomly assigned to chemotherapy alone received the second course of induction chemotherapy as soon as clinically indicated; patients randomly assigned to receive chemotherapy plus sequential lestaurtinib had lestaurtinib withheld for 3 days (72 hours) before the start of the second 5-day course of chemotherapy and resumed lestaurtinib treatment 2 days (48 hours) after the final administration of the second course of chemotherapy.