A Retrospective Study on Inotuzumab Ozogamicin in Infants and Young Children with Relapsed or Refractory Acute Lymphoblastic Leukemia (ALL)

Pieters: medac: Consultancy; jazz farmaceuticals: Consultancy. Zwaan:Celgene: Consultancy, Research Funding; Roche: Consultancy; Sanofi: Consultancy; Novartis: Consultancy; Daiichi Sankyo: Consultancy; Servier: Consultancy; BMS: Research Funding; Pfizer: Consultancy, Research Funding; Janssen: Consultancy; Jazz pharmaceuticals: Other: Travel support; Incyte: Consultancy.Inotuzumab ozogamicin (InO) is a CD22-directed monoclonal antibody linked to calicheamicin. It is approved for adults with relapsed/refractory (R/R) CD22+ B-cell precursor acute lymphoblastic leukemia (BCP-ALL) at the dose of 1.8 mg/m2/course fractionated at day 1, 8 and 15 (Kantarjian, NEJM, 2016). The pediatric experience with InO is still limited. Patients (pts) <1 year of age cannot be enrolled onto the ongoing Phase 1-2 clinical trial and no data for this age group are published so far. Drug administration in these pts with very low Body Surface Area (BSA), unique body composition and drug disposition is always challenging, especially with new agents with unknown toxicities. Infant ALL is characterized by a dismal prognosis with an EFS of 47% in newly diagnosed pts, and of 20% after relapse (Driessen, Leukemia 2017). There is an unmet need for innovative strategies in these pts.