Used in the treatment of chronic lymphocytic leukemia (CLL), particularly in patients with 17p deletion, a genetic abnormality that makes the disease harder to treat. It works by selectively inhibiting BCL-2, a protein that cancer cells rely on to survive and avoid programmed cell death. By blocking BCL-2, the compound triggers apoptosis in cancer cells, especially in certain blood cancers. It has shown significant efficacy in clinical trials, leading to high response rates and improved progression-free survival. Often used when other therapies fail or in targeted treatment regimens with minimal chemotherapy. Also being studied in other hematologic malignancies such as acute myeloid leukemia (AML) and non-Hodgkin lymphoma.