Pharmacodynamic activity of obatoclax monitored using 3 different end points. (A) Example of time course in PBMNCs following a 1-hour infusion of obatoclax in a patient initially receiving 3.5 mg/m² and later dose-escalated to 10 mg/m². Left panel, Western blot analysis of total Bax expression. Right panel, Western blot analysis of Bax coimmunoprecipitated with activated Bak. (B) Relationship between relative change in plasma concentration of oligonucleosomal DNA/histone complexes and obatoclax exposure in individual patients (N = 26). (C) Relative decrease in lymphocyte count from baseline in individual patients (N = 18).