Efficacy and tolerability of gemtuzumab ozogamicin (anti-CD33 monoclonal antibody, CMA-676, Mylotarg®) in children with relapsed/refractory myeloid leukemia
1 Unité de Pédiatrie à Orientation Hématologique, Hôpital Saint-Louis, Paris, France
2 Unité d'Onco-Hématologie Pédiatrique, Hôpital d'Enfants Armand Trousseau, Paris, France
3 Unité d'Immuno-Hématologie Pédiatrique et Transplantation de Moelle Osseuse, Hôpital Debrousse, Lyon, France
4 Unité d'Hématologie Pédiatrique, Hôpital Robert Debré, Paris, France
BMC Cancer 2006, 6:172 doi:10.1186/1471-2407-6-172Published: 28 June 2006
Gemtuzumab ozogamicin (GO) is a cytotoxic anti-CD33 monoclonal antibody that has given promising preliminary results in adult myeloid CD33+ AML. We conducted a retrospective multicenter study of 12 children treated with GO on a compassionate basis (median age 5.5 y). Three patients (2 MDS/AML, 1 JMML) were refractory to first-line treatment, 8 patients with de novo AML were in refractory first relapse, and one patient with de novo AML was in 2nd relapse after stem cell transplantation (SCT). CD33 expression exceeded 20% in all cases.
GO was administered alone, at a unit dose of 3–9 mg/m2, once (3 patients), twice (3 patients), three (5 patients) or five times (1 patient). Mean follow-up was 128 days (8–585 d).
There were three complete responses (25%) leading to further curative treatment (SCT). Treatment failed in the other nine patients, and only one patient was alive at the end of follow-up. NCI-CTC grade III/IV adverse events comprised hematological toxicity (n = 12), hypertransaminasemia (n = 2), allergy and hyperbilirubinemia (1 case each). There was only one major adverse event (grade IV allergy). No case of sinusoidal obstruction syndrome occurred.
These results warrant a prospective trial of GO in a larger population of children with AML.