Figure 1. ABT-199 selectively kills BCL-2 dependent tumor cells while sparing platelets.
(A) Navitoclax (ABT-263) binds with high affinity to both BCL-2 and BCL-XL. Since many tumors, particularly lymphoid malignancies, are addicted to BCL-2 for survival, this potently induces tumor cell apoptosis. Platelets depend primarily on BCL-XL for survival, and therefore are also destroyed by navitoclax. (B) ABT-199 is specific for BCL-2 and induces selective death of BCL-2 dependent tumor cells while sparing platelets.