Tafasitamab (MOR00208) in Pediatric Patients With Relapsed or Refractory Acute B Lineage Leukemia

Inclusion Criteria: * Age ≥ 3 years and \< 18 years at enrollment * B-lineage (CD19 positive) ALL (B, pro-B, pre-B or c-ALL) * Patients must have either * underwent a first allogeneic stem cell transplantation after relapse with one of the following very high-risk somatic molecular alterations: * KMT2A::AFF1 \[t(4;11) rearrangement * TP53 alteration (mutation/deletion) * low hypodiploidy (\<40 chromosomes, evident or masked) * TCF3-PBX1 \[t(1;19)\] * TCF3::HLF \[t(17;19)\] and irrespective of MRD after SCT or * underwent a first allogeneic stem cell transplantation or a CAR T-cell therapy with newly emerging or persistent MRD load posttransplant / post CAR T- cell-treatment or * have received stem cell transplantation without having reached a sufficient molecular remission prior to transplant (defined as MRD ≥10E-4) irrespective of MRD after SCT or * underwent a second or subsequent allogeneic stem cell transplantation irrespective of MRD after SCT * Females of childbearing potential (FCBP1) must agree * to utilize two reliable forms of contraception simultaneously or practice complete abstinence from heterosexual contact for at least 3 months before starting study drug, while participating in the study (including dose interruptions), and for at least 3 months after study treatment discontinuation and must agree to regular pregnancy testing during this timeframe * to abstain from breastfeeding during study participation and 3 months after s…