X-339 Potent & Selective PI3Kδ Inhibitor

The P110δ isoform of PI3K, most prominently expressed in myeloid cells, has been shown to play an essential role in cell proliferation in acute myeloid leukemia (AML) and has also been implicated in tumor angiogenesis, particularly in the context of repair after destruction of tumor blood vessels with radiation. P110δ is critical for signaling through the B cell receptor and regulates pathways that control cell proliferation and survival. Inhibition of P110δ effectively inhibits B cell chronic lymphocytic leukemias and some B cell non-Hodgkin lymphomas.

Xcovery’s X-339 is a selective and potent inhibitor of the P110δ isoform of PI3K. X-339 has a different binding mode than competitive P110δ inhibitors and may therefore be able to overcome acquired resistance.

Because normal B lymphocyte function is also regulated by P110δ, X-339 may be effective alone or in combination with other immunosuppressive drugs in autoimmune and inflammatory diseases like rheumatoid arthritis. Signaling through FCRεI on basophils is also dependent on P110δ, suggesting that X-339 may be effective as well in treating allergic diseases.