Entospletinib is primarily used in the treatment of certain types of blood cancers, particularly those involving B-cell malignancies. It is specifically investigated for its role in targeting and inhibiting Bruton's tyrosine kinase (BTK) and spleen tyrosine kinase (SYK), which are critical in the signaling pathways of cancer cells. This makes it a potential therapeutic option for conditions like chronic lymphocytic leukemia (CLL), non-Hodgkin lymphoma (NHL), and acute myeloid leukemia (AML). By blocking these kinases, Entospletinib helps to reduce the proliferation and survival of malignant cells, offering a targeted approach to cancer therapy. It is often studied in combination with other drugs to enhance its efficacy and improve patient outcomes.