Effect of T-DM1 on the growth of JIMT-1 xenografts. SCID mice were injected s.c. with 5 × 106 JIMT-1 cells. Tumours were formed in all mice in 11 days (n = 18, mean tumour volume 64 ± 9 mm3). Thereafter, weekly treatments (arrows) with control antibody (rituximab, 5 mg/kg, i.p., white circle, n = 6), trastuzumab (5 mg/kg, i.p., black triangle, n = 6) or T-DM1 (15 mg/kg, i.v., white triangle, n = 6) were started on Day 12 and continued until the end of the experiment. A partial but significant tumour growth inhibition was seen by T-DM1 from days 32 to 44 (*, P < 0.05), while trastuzumab had no inhibitory effect on tumour growth.