Gemtuzumab ozogamicin (Mylotarg) was granted an extended indication by FDA for newly-diagnosed CD33-positive acute myeloid leukemia to include pediatric patients 1 month and older.
Mylotarg is sponsored by Wyeth Pharmaceuticals LLC.
Efficacy and safety in the pediatric population were supported by data from AAML0531 (NCT00372593), a multicenter randomized study of 1,063 patients with newly-diagnosed AML ages 0 to 29 years. Patients were randomized to five-cycle chemotherapy alone or with gemtuzumab ozogamicin (3 mg/m2) administered once on day 6 in Induction 1 and once on day 7 in Intensification 2.
The main efficacy outcome measure was event-free survival measured from the date of trial entry until induction failure, relapse, or death by any cause. The EFS hazard ratio was 0.84 (95% CI: 0.71-0.99). The estimated percentage of patients free of induction failure, relapse, or death at five years was 48% (95% CI: 43%-52%) in the gemtuzumab ozogamicin + chemotherapy arm versus 40% (95% CI: 36%‑45%) in the chemotherapy alone arm. No difference between treatment arms in overall survival was demonstrated.
