A drug used to treat chronic lymphocytic leukemia (CLL) in patients who have already received other treatment. It is used in patients whose cancer has a change in chromosome 17. It is also being studied in the treatment of other types of cancer. Venclexta binds to a protein called BCL2, which may be found on some types of leukemia cells. Blocking this protein may help kill cancer cells and may make them more sensitive to other anticancer drugs. Venclexta is a type of BCL2 inhibitor. Also called venetoclax.