A-1331852 is an orally bioavailable Bcl-xL inhibitor that selectively binds Bcl-xL over Bcl-2, Mcl-1, and Bcl-W (K
is = <0.01, 6, 142, and 4 nM, respectively).
1 It inhibits growth of Bcl-xL-dependent MOLT-4, but not Bcl-2-dependent RS4;11, acute lymphocytic leukemia cells
in vitro (EC
50s = 6 and >5,000 nM, respectively). A-1331852 (25 mg/kg twice per day) inhibits tumor growth in a MOLT-4 mouse xenograft model. It also inhibits tumor growth and increases the antitumor activity of docetaxel (Item No.
11637) in MDA-MB-231 LC3 metastatic breast cancer and NCI-H1650 non-small cell lung cancer mouse xenograft models when administered at a dose of 25 mg/kg. A-1331852 also increases venetoclax inhibition of tumor growth in an NCI-H1963.FP5 small cell lung cancer mouse xenograft model.