Figure 4.

Sabizabulin inhibits tumor growth and induces apoptosis in orthotopic BT474 xenografts. (A) Mean tumor volume (mm³) was measured over the course of treatments (days on therapy): vehicle (IP, 3×/week, n = 19 total tumors), paclitaxel (10 mg/kg, IP, 3×/week, n = 17 total tumors), or sabizabulin (17 mg/kg, PO, 3×/week, n = 21 total tumors). Mean tumor wet weight (B) and mean ex vivo measured tumor volume (C) are shown at experiment endpoint (33 days). (A–C) The mean values are also indicated above each treatment group. All p-values were calculated as pairwise comparisons relative to the vehicle control group at 33 days; ** p < 0.01; **** p < 0.001. (D) Mean percent (%) change in body weight over time for vehicle (n = 11 mice), paclitaxel (n = 11 mice), or sabizabulin (n = 12 mice); dashed lines indicate initial body weight (y = 0) with a −10% to +10% variance over time (days on therapy). (E) Images of resected tumors. (F) Representative images of slides stained with cleaved caspase-3 (600× magnification; scale bar, 50 μM); yellow arrowheads indicate examples of positive cells. (G) Quantification of cleaved caspase-3; p-values calculated by t-tests, with Welch’s correction. N.S., not significant. (H) Cleaved PARP signal bywestern blotting of whole tumor extracts with signal normalized to GAPDH (CST 3683) and analyzed by densitometry, with the vehicle-treated signal set to 1.0.