BI 836858 + decitabine

BI 836858 + decitabine is a combination therapy investigated for the treatment of acute myeloid leukemia (AML) in elderly patients and those with relapsed or refractory AML. **BI 836858** is a fully humanized, unconjugated IgG1 monoclonal antibody that binds CD33, mediating anti-leukemic activity mainly through antibody-dependent cellular cytotoxicity (ADCC), depletion of CD33-positive blasts, and modulation of immune-suppressive cytokine secretion. **Decitabine** is a small molecule, DNA hypomethylating agent, and induces differentiation and apoptosis of malignant cells via epigenetic modulation. This combination intended to exploit both direct cytotoxic and immune-mediated antitumor effects. The regimen was investigated in a phase I/II open-label, multicenter clinical trial (NCT02632721) in Europe and the US, but development was terminated prior to phase II completion. No maximum tolerated dose was formally established, but BI 836858 at 80 mg with standard decitabine was considered tolerable. The study observed partial reductions in CD33+ blasts, some increase in activated NK cells, and an objective response rate, but clinical efficacy remained uncertain due to early study discontinuation.