A liquid pharmaceutical composition comprises an aqueous medium having suspended therein a solid particulate Bcl-2 family protein inhibitory compound such as ABT-263, having a Dparticle size not greater than about 3 μm; wherein the aqueous medium further comprises at least one pharmaceutically acceptable surfactant and at least one pharmaceutically acceptable basifying agent such as sodium bicarbonate in amounts that are effective together to inhibit particle size increase. The composition is suitable for oral or parenteral administration to a subject in need thereof for treatment of a disease characterized by overexpression of one or more anti-apoptotic Bcl-2 family proteins, for example cancer.