Figure 5.

(A) Antitumour effect of (i) metronomic CPT-11 4 mg kg⁻¹ i.p. daily, (ii) CPT-11 100 mg kg⁻¹ i.p. every week (MTD schedule) and (iii) an initial single dose of CPT-11 100 mg kg⁻¹ i.p. followed by metronomic CPT-11 4 mg kg⁻¹ i.p. daily on HT-29 tumours xenotransplanted in CD nu/nu mice. ^*P<0.05 with respect to controls. Symbols and bars, mean±s.e. (B) Body weight of HT-29 tumour-bearing control mice and mice treated with metronomic CPT-11, MTD CPT-11 and the single high dose followed by the metronomic schedule. MTD CPT-11 caused a severe loss of weight that required veterinary assistance with an immediate fluid therapy (↑; 0.9% saline, 40–80 ml kg⁻¹ s.c. every 24 h) to save the animals. The group of animal at MTD CPT-11 needed a continued supportive fluid therapy for the duration of the treatment, whereas mice treated with a single initial dose of 100 mg kg⁻¹ and metronomic maintenance did not need any additional fluid therapy until the end of the study. Symbols and bars, mean±s.e.