PRIME ('203) Study DesignThe PRIME ( Panitumumab Randomized trial In combination with chemotherapy for Metastatic colorectal cancer to determine Efficacy) ('203) trial is a global, multicenter, randomized Phase 3 study designed to evaluate Vectibix (6.0 mg/kg every two weeks) plus FOLFOX versus FOLFOX alone in patients with wild-type KRAS exon 2 mCRC. The primary endpoint is PFS.
The primary objective of this predefined retrospective subset analysis was to determine the effect of Vectibix plus FOLFOX versus FOLFOX alone on OS and PFS in patients with mCRC based on RAS or BRAF mutation status. The analysis included 512 patients who were identified with wild-type RAS tumors.
About KRAS and RAS Results from studies performed over the last 30 years indicate that
KRAS plays an important role in cell growth regulation. In mCRC, EGFR transmits signals through a set of intracellular proteins. Upon reaching the nucleus, these signals instruct the cancer cell to reproduce and metastasize, leading to cancer progression.
1 Anti-EGFR antibody therapies work by inhibiting the activation of EGFR, thereby inhibiting downstream events that lead to malignant signaling. However, in patients whose tumors harbor a mutated
KRAS gene, the KRAS protein is always turned "on," regardless of whether the EGFR has been activated or therapeutically inhibited. Common
KRAS mutations occurring in exon 2 (codons 12/13) are present in approximately 40 to 50 percent of mCRC patients.
RAS mutations occurred in approximately 17 percent of patients with wild-type
KRAS exon 2 tumors.
About Colorectal CancerColorectal cancer is the third most common cancer found in both men and women in the U.S., and is the second leading cause of cancer deaths. 4,5 Approximately 1.2 million cases of colorectal cancer are expected to occur globally. The highest incidence rates are found in Japan, North America, parts of Europe, New Zealand and Australia, and rates are low in Africa and Southeast Asia. 6