Additional RAS mutations predicted a lack of response in patients who received panitumumab-FOLFOX4. In patients who had metastatic colorectal cancer without RAS mutations, improvements in overall survival were observed with panitumumab-FOLFOX4 therapy. (Funded by Amgen and others; PRIME ClinicalTrials.gov number, NCT00364013.).

This study demonstrated that panitumumab-FOLFOX4 was well tolerated and significantly improved PFS in patients with WT KRAS tumors and underscores the importance of KRAS testing for patients with mCRC.

Both regimens achieved similar median survival times more than 18 months with an acceptable toxicity. The chronomodulated schedule produced a survival advantage over FOLFOX in men. The strong sex dependency of optimal scheduling of fluorouracil, leucovorin, and oxaliplatin calls for translational investigations of determinants related to the patient's molecular clock.