JNJ-28312141 is an orally active CSF1R inhibitor (Colony-stimulating factor-1 receptor, CRF1R) and also a FLT3 inhibitor. CSF1R is expressed by many tumors and is a growth factor for macrophages and mediates osteoclast differentiation. JNJ-28312141 represents a new agent with potential therapeutic activity in acute myeloid leukemia and in settings where CSF-1-dependent macrophages and osteoclasts contribute to tumor growth and skeletal events.