EOS006215 is a humanized monoclonal antibody inhibitor targeting TREM-2. It has the ability to reprogram TREM2+ macrophages, significantly hindering their tumor-promoting activities and overcoming drug resistance. In mouse models with orthotopic 4T1 triple-negative breast cancer, EOS006215 reduces metastatic burden. Additionally, it notably inhibits tumor growth in anti-PD-1 resistant mouse models. EOS006215 is applicable for studies on triple-negative breast cancer (TNBC).