BI 836858

BI 836858 is a fully humanized IgG1 unconjugated anti-CD33 monoclonal antibody that was developed as an intravenously administered therapy for hematologic malignancies, primarily acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS)[1][4][7]. The antibody is fragment crystallizable (Fc)-engineered to enhance binding to FcγRIIIa (CD16) on natural killer (NK) cells, thereby increasing antibody-dependent cellular cytotoxicity (ADCC)[1][5][6]. Preclinical studies demonstrated that BI 836858 binds CD33 with high affinity and mediates potent ADCC against leukemic blasts[6]. In clinical trials, it was evaluated in relapsed/refractory AML and transfusion-dependent low- or intermediate-risk MDS but did not show significant clinical responses[4][8]. Development has been discontinued for these indications[7].