Macrophages are major constituents of the microenvironment in many cancers, promoting carcinogenesis, malignant progression and resistance to therapy making them attractive targets for therapeutic intervention. Macrophage Pharma’s approach is to manipulate tumour associated macrophages to inhibit the immunosuppression that they generate, leading to more effective anti-tumour immune responses. Esterase Sensitive Motif technology represents a strategy of highly selective delivery of small molecule inhibitors to tumour macrophages such that the function of other important anti-tumour immune cells is not impacted. Macrophage Pharma believes that development of these highly novel therapeutics will lead to optimal anti-tumour macrophage activities providing maximal therapeutic responses.