Amgen has announced new data from the Phase 2 PEAK and Phase 3 PRIME studies that support the first-line use of Vectibix (panitumumab) in combination with FOLFOX, an oxaliplatin-based chemotherapy regimen, in patients with wild-type RAS (absence of exons 2, 3, or 4 KRAS or NRAS mutations) metastatic colorectal cancer (mCRC). The data will be presented during a poster session at the 2015 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium taking place in San Francisco from January 15 to 17.
In an exploratory analysis from the PEAK study (abstract #660), treatment with Vectibix compared to bevacizumab (Avastin®) resulted in a significantly higher proportion of patients with earlier tumor shrinkage at week eight (64 percent vs. 45 percent, respectively; 95 percent CI, p=0.0232), and among responding patients, a significantly longer duration of response (11.4 vs. 8.5 months, respectively; 95 percent CI, p=0.0142) and greater depth of response (65 percent vs. 46 percent, respectively; p=0.0007). Overall response rates (ORR) appeared to be similar between Vectibix and bevacizumab. This is consistent with observed overall survival (OS) and progression-free survival (PFS) rates, and with data previously reported. The safety profile of Vectibix was consistent with previously reported studies.
“These analyses help deepen our understanding of how Vectibix works when added to a standard first-line chemotherapy for the treatment of wild-type RAS metastatic colorectal cancer,” said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. “Our Vectibix clinical trial program continues to yield new insights regarding biomarkers and drug sequencing.”
While the primary analysis from PEAK showed similar ORR between the Vectibix- and bevacizumab-based regimens, this exploratory analysis demonstrates that Vectibix produces early, sustained anti-tumor activity, which may in part explain the OS and PFS benefits seen with Vectibix versus bevacizumab in this trial.
A separate analysis from the Phase 3 PRIME study (abstract #537), demonstrated that there were no significant differences in quality of life among patients treated with Vectibix plus FOLFOX versus FOLFOX alone despite the incidence of adverse events associated with each treatment regimen. The quality of life analysis included a scale that assessed mobility, self-care, usual activities, pain/discomfort and anxiety/depression.
Colorectal 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.1,2 Approximately 1.2 million cases of colorectal cancer are expected to occur globally each year.3
1 Colorectal Cancer Facts and Figures. American Cancer Society website. http://www.cancer.org/cancer/colonandrectumcancer/detailedguide/colorectal-cancer-key-statistics. Accessed December 23, 2014.
2Colorectal Cancer Prevention (PDQ®). National Cancer Institute website. http://www.cancer.gov/cancertopics/pdq/prevention/colorectal/HealthProfessional/page3. Accessed December 23, 2014.
3Jemal. Global Cancer Statistics. CA Cancer J Clin. 2011;61:69-90.