Amgen announced results from the phase 2 PEAK study that reinforce the improved overall survival (OS) benefit of panitumumab (Vectibix) when used in combination with Folfox, an oxaliplatin-based chemotherapy regimen, compared to bevacizumab (Avastin) plus Folfox as first-line treatment in patients with wild-type RAS metastatic colorectal cancer (mCRC). The data was presented at the 50th Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago

The data presented at ASCO was an extended analysis of the PEAK study that supports the use of panitumumab in combination with Folfox for patients with wild-type RAS (absence of exons 2, 3, or 4 KRAS or NRAS mutations) mCRC.

In this exploratory analysis, patients who received panitumumab plus Folfox and were then treated with a VEGF inhibitor-based treatment (including bevacizumab) had a median OS improvement of 41.3 months. By comparison, patients who received bevacizumab plus Folfox and were then treated with an anti-EGFR inhibitor-based treatment (including panitumumab/cetuximab), had a median OS improvement of 29.0 months. For both arms, outcomes were similar to those observed in the overall treated population with wild-type RAS mCRC.

"The initial PEAK data reinforce the potential importance of panitumumab for select patients, but we wanted to evaluate whether this benefit was dependent on administration with Folfox and if other subsequent treatments might impact survival outcomes," said Fernando Rivera, managing director, Medical Oncology Department, Hospital Universitario Marques de Valdecilla, Santander, Spain, and a lead investigator in the study. "These data suggest that a front-line treatment strategy with panitumumab in combination with Folfox may offer clinical benefit in patients with wild-type RAS metastatic colorectal cancer compared to bevacizumab-based regimens in this treatment setting."

"The PEAK study not only shows the survival benefit of panitumumab in patients who have metastatic colorectal cancer with wild-type KRAS tumors, but also gets us another step closer to understanding how unique genetic markers may change the way we treat cancers," said Sean E. Harper, managing director, s executive vice president of research and development(R&D) at Amgen. "Every study we conduct as part of our comprehensive panitumumab development programme adds to a growing understanding of how to personalise care for cancer patients."

Colorectal cancer is the third most common cancer in the US, and is the second leading cause of cancer deaths. Approximately 1.2 million cases of colorectal cancer are expected to occur globally.