ABT-199

Venetoclax (ABT-199, GDC-0199) is a Bcl-2-selective inhibitor with Ki of 4800-fold more selective versus Bcl-xL and Bcl-w, and no activity to Mcl-1. Phase 3. (In Vitro) :Venetoclax (ABT-199) potently kills FL5.12-BCL-2 cells (EC50=4 nM), Venetoclax (ABT-199) shows much weaker activity against FL5.12-BCL-XL cells (EC50=261 nM) . ABT-199 also shows selectivity in cellular mammalian two-hybrid assays, where it disrupts BCL-2-BIM complexes (EC50=3 nM) but is much less effective against BCL-XL-BCL-XS (EC50=2.2 μM) or MCL-1-NOXA complexes. (In Vivo) :After a single oral dose of 12.5 mg per kg body weight in xenografts derived from RS4;11 cells (ALL), Venetoclax (ABT-199) causes a maximal tumor growth inhibition (TGImax) of 47% (P<0.001) and tumor growth delay (TGD) of 26% (P<0.05) .Treatment of established xenografted (a mouse xenograft model of the T-ALL cell line LOUCY) tumors with Venetoclax (ABT-199) 100 mg/kg for 4 days results in a significant reduction of leukemic burden.