Antitumor effect and tolerability of NVP-AUY922 in a BT-474 human breast cancer xenograft model. BT-474 cells were inoculated subcutaneously in female nude mice carrying an estrogen-release pellet. When the tumors reached 100 to 200 mm3, drug treatment was initiated. Each group consisted of eight animals. NVP-AUY922 was administered (a) as a single injection, (b) three times per week (3qw), or (c) once per week (qw) at the indicated dose levels. Tumor volumes and body weights were measured three times per week. Each point represents the mean ± standard error of the mean (SEM). Arrows in right panels indicate NVP-AUY922 treatment days. Asterisks indicate statistical significance compared with vehicle-treated controls (P < 0.05, one-way analysis of variance post hoc Dunnett). i.v., intravenous.