THOUSAND OAKS, Calif.—Claiming a victory in reinforcing its commitment to personalized medicine, Amgen announced May 23 that that the U.S. Food and Drug Administration (FDA) has approved Vectibix (panitumumab) for use in combination with FOLFOX, an oxaliplatin-based chemotherapy regimen, as a first-line treatment in patients with wild-type KRAS (exon 2) metastatic colorectal cancer (mCRC).
This makes Vectibix the first—and thus far only—biologic to offer a significant survival benefit as a first-line treatment with FOLFOX, one of the most commonly used chemotherapy regimens in the first-line setting for patients with wild-type KRAS mCRC, Amgen notes.
Along with this approval comes the conversion of the accelerated approval for Vectibix as a monotherapy to a full approval. Furthermore, the FDA also approved the therascreen KRAS RGQ PCR Kit developed by QIAGEN as a companion diagnostic for Vectibix.
“Because every patient with cancer is unique, we have made it our mission to focus on identifying treatment options for patients based on their cancer’s genetic makeup,” said Dr. Sean E. Harper, executive vice president of research and development at Amgen. “Approval of Vectibix in combination with FOLFOX for first-line treatment of patients with wild-type KRAS metastatic colorectal cancer is an example of the advancements that can be made through a greater understanding of distinct genetic markers associated with difficult-to-treat diseases.”
The approval is based on results from Amgen’s PRIME and ASPECCT clinical trials. The PRIME Phase 3 study showed that patients with wild-type KRAS tumors in exon 2 achieved statistically significant improvement in progression-free survival with Vectibix and FOLFOX versus FOLFOX alone, coming out to 9.6 months in combination vs. 8 months for FOLFOX alone. In addition, the overall survival of 23.8 months with the combination therapy is an improvement of 4.4 months compared to FOLFOX alone.
The Phase 3 ASPECCT study also met its primary endpoint of non-inferiority for improving overall survival in patients taking Vectibix versus Erbitux (cetuximab) as a single agent for the treatment of mCRC in patients with wild-type KRAS tumors who have not responded to chemotherapy.
As Amgen notes, colorectal cancer is the third most common cancer found in both men and women in the United States and is the second leading cause of cancer deaths. Approximately 1.2 million cases of colorectal cancer are expected to occur globally.
Vectibix is the first fully human anti-EGFR antibody approved by the FDA for the treatment of mCRC and was approved previously in September 2006 as a monotherapy for the treatment of patients with EGFR-expressing mCRC after disease progression after prior treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy.
Looking at results from its Phase 2 PEAK clinical study as well, Amgen maintains that Vectibix not only shows benefits in patients who have select genetic mutations, but also “may represent a potential shift in the colorectal cancer treatment paradigm where EGFR inhibitors like Vectibix may be used as a standard first-line colorectal cancer treatment.”
In mid-May, commenting on results of the PRIME and PEAK trials, Amgen cited the description of new predictive biomarkers of clinical response to Vectibix, activating mutations in KRAS beyond exon 2 and mutations in NRAS, collectively referred to as RAS, with Harper saying, “Amgen helped establish KRAS gene mutation as a biomarker for lack of response to anti-EGFR treatment. The identification of new biomarkers may further help to identify appropriate patients with this incurable disease for such treatment.”
