Provided herein are pharmaceutical compositions comprising a phosphatidylinositol 3-kinase inhibitor, or pharmaceutically acceptable form thereof, in combination with a second agent, or a pharmaceutically acceptable form thereof, wherein the second agent is chosen from one or more of 1) a CDK4/6 inhibitor, 2) an HDAC inhibitor, 3) a MEK inhibitor, 4) a mTOR inhibitor, 5) an AKT inhibitor, 6) a proteasome inhibitor, 7) an immunomodulator, 8) a glucocorticosteroid, 9) a BET inhibitor, 10) an epigenetic inhibitor, 11) a PI3K alpha inhibitor, 12) a topoisomerase inhibitor, or 13) an ERK inhibitor. Also provided herein are methods of treatment comprising administration of the compositions, and uses of the compositions, e.g., for treatment of cancer.
