Six hundred and seventy-two patients with advanced, measurable CRC following prior fluoropyrimidine-containing chemotherapy were randomised to either irinotecan 3-weekly 350 mg/m2 (or 300 mg/m2 if age >70 or performance status (PS) = 2) or 3-weekly irinotecan at 140 mg/m2 (120 mg/m2 if age >70 or PS = 2) with ciclosporin 3 mg/kg t.d.s. for three days by mouth starting on the morning before irinotecan. The primary end-point was the proportion of patients alive and progression-free at 12 weeks. The key secondary end-point was the incidence of grade ?3 diarrhoea within 12 weeks of randomisation.
The proportion of patients progression-free at 12 weeks with irinotecan was 53.4 % compared to 47.2 % with irinotecan plus ciclosporin (difference = ?6.3 % , 95 % confidence interval (CI) [?13.8 % , 1.3 % ]). Since the lower limit of the 95 % CI crossed the pre-specified non-inferiority margin of ?10.6 % , non-inferiority of irinotecan plus ciclosporin compared to irinotecan alone was not statistically demonstrated. 15.0 % patients developed severe diarrhoea on irinotecan compared to 13.8 % on irinotecan plus ciclosporin, a non-significant difference.
The pharmacokinetic biomodulation of irinotecan using oral ciclosporin does not improve the therapeutic index of irinotecan in advanced CRC.
The trial was funded by Cancer Research UK and supported by Amgen Pharma.