Irinotecan in second-line treatment of metastatic colorectal cancer: improved survival and cost-effect compared with infusional 5-FU.

In a recent multicentre, randomised, controlled, open-label study (Rougier and colleagues, Lancet 1998, 352, 1407-1412), irinotecan significantly increased survival without any deterioration in quality of life compared with best-estimated infusional 5-fluorouracil (5-FU) therapy in the setting of second-line treatment for metastatic colorectal cancer. The aim of the cost-effectiveness analysis reported here was to compare the economic implications, from a U.K. perspective, of replacing 5-FU therapy [either as a single agent (Lokich regimen, B2) or in combination with folinic acid (de Gramont regimen, B1, or AIO regimen, B3)] with irinotecan as second-line therapy for metastatic colorectal cancer. Resource utilisation data collected prospectively during the study, supplemented by both a questionnaire to investigators and local expert clinical opinion, were used as a basis for estimating cumulative drug dosage, chemotherapy administration and treatment of complications. Drug acquisition costs were derived from the British National Formulary (March 1998), and unit costs for clinical consultation and services were derived from relevant 1996/1997 cost databases. Although cumulative drug acquisition costs per patient were higher with irinotecan than with infusional 5-FU therapy, these were at least partially offset by lower cumulative costs per patient associated with administration of therapy and treatment of complications in the irinotecan arm than in the 5-FU arm. Based on the incremental costs per life year gained (LYG), irinotecan was considered to be cost-effective by commonly accepted criteria compared with either the B1 or B2 regimens. Irinotecan was cost-saving compared with the B3 regimen (that is significant survival gain and a reduction in costs). Thus, not only is there strong evidence for the use of irinotecan as standard second-line therapy in metastatic colorectal cancer,but the results of this prospective economic evaluation have shown that irinotecan also represents good value for money in this clinical setting.