Polyethylene glycol 400

For in vivo studies, T-DM1 (Genentech) was administered i.p. at 10 mg/kg once per week. ABT-737 (AbbVie) was administered i.p. at 70 mg/kg once per day. ABT-263 (AbbVie) was administered p.o. at 70 mg/kg once per day. T-DM1 was prepared according to Genentech recommendations in sterile water for injection (Gibco). ABT-737 and ABT-263 were prepared according to AbbVie recommendations. ABT-737 in 30% propylene glycol (Sigma) plus 0.5% Tween 80 (Sigma) and 65% D5W (5% dextrose in water, Sigma) pH 3–4 and ABT-263 in 60% PHOSAL 50 PG (Lipoid) plus 30% polyethylene glycol 400 (Dow Chemical) and 10% ethanol. Matched control animals received vehicle alone in the same manner as drug-treated counterparts. All animals were randomized into groups and weighed before treatment. Individual weights were used for dose calculations. Weights were re-measured at the 14-day experimental end point. Weight reductions >20% prevented continuous treatments beyond 14 days.