Acalisib is primarily used in the field of oncology as a targeted therapy for certain types of cancers. It functions as a potent inhibitor of the PI3K delta isoform, which plays a crucial role in the growth and survival of cancer cells. This makes it particularly effective in treating hematologic malignancies, such as chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL). By blocking the PI3K pathway, Acalisib disrupts the signaling mechanisms that promote tumor progression, leading to reduced proliferation and increased apoptosis of cancer cells. It is often used in patients who have not responded well to other treatments or in combination with other anticancer agents to enhance therapeutic outcomes. Ongoing research is exploring its potential in other cancer types and its efficacy in overcoming resistance to traditional therapies.