Pharmacoeconomic analysis for K-Ras status–based decisions for first-line therapy of metastatic colorectal cancer (mCRC) in Spain.

438 Background: Personalized medicine is a challenge for current oncology practice. Nowadays there are no pharmacoeconomic analyses in Spain dealing with the clinical and financial impact secondary to K-Ras based decisions for first-line therapy in mCRC patients. So, this study was aimed to assess the cost- effectiveness of K-Ras status based decisions in first- line therapy of mCRC patients in comparison with non- K-Ras based selection of available therapies. Methods: K-Ras mutation prevalence and efficacy of available therapies (measured as response rate and progression free survival) were extracted from randomized clinical trials (RCT) that allowed on-label use of accessible drugs in Spain. Then, we have simulated all possibilities of combination therapies for first-line mCRC based on K-Ras status (wild- type vs mutated) and confronted with all therapies that could be chosen in absence of K-Ras analysis. Prices for all drugs in Spain were used to assume the best- value for each drug including all possi...