Cost-Effectiveness Analysis Of Cetuximab As Third-Line Treatment In Metastatic Colorectal Cancer

15090 Background: Cetuximab monotherapy provides 1.5 month survival improvement against best supportive care (BSC) in metastatic colorectal cancer (mCRC) (Jonker et al NEJM 2007; 357: 2040–48). Cetuximab-irinotecan combination prolongs time to progression but its effect on survival has no been ellucidated in fase III trials. New drugs have increased expenses in oncological departments. Cost- effectiveness analysis are needed. Methods: Retrospective comparative study of 35 patients treated with weekly cetuximab- irinotecan versus 30 consecutive historic controls treated with BSC, after progression to 5-fluorouracil, irinotecan and oxalipatin in mCRC. Primary end-points were analysis of survival (time from progression to second line treatment or start of cetuximab until death) and the cost of each week gained with cetuximab-irinotecan. Data analysed were number of blood analysis, CT scans, Rx, MRI, medical outpatient visits, hospital admissions and emergency episodes. Nonparametric tests were used. Results: Both groups were well-balanced as for gender, age (median 59), stage, adjuvant treatment and primary tumour location. All 65 patients received 2 palliative lines. No statistically significant differences in median number of cycles were found. One site only metastatic location was present in 43.3% controls and 22.9% cases. PS was higher or equal to 2 in 63.4% controls and 8.6% cases (p<0.001). Median number of cetuximab infusions were 6 (range 35). Eighty percent cases progressed on cetuximab treatment. The most common toxicity was dermathologic (88.6%), and the most common grade 3–4 toxicities were G-I and constitutional (each 40%). Median survival was 6.99 months (range 17.91) for cases and 3.02 (range 27.89) for controls (p<0.03). Cost of one week of life since start of cetuximab (cases) or since last progression to chemotherapy (controls) was 473.69 euros (range 1232.16) for cases and 173.04 (range 1781.19) for controls (p<0.001). Conclusions: The control group had worse predefined prognosis than the treatment group due to lower PS. The cost of survival benefit of cetuximab-irinotecan as third line treatment will be compared against an extended control cohort with well-balanced prognostic factors including PS. Results of these analysis will be presented. No significant financial relationships to disclose.