Amgen’s Vectibix With Chemotherapy To Improve Progression-Free Survival

Amgen has reported that Vectibix (panitumumab), administered in combination with Folfox (an oxaliplatin-based chemotherapy), prolonged progression-free survival (PFS), as compared to Folfox alone in the treatment of KRAS wild-type metastatic colorectal cancer (mCRC).

The study was amended from the original, to analyze outcomes with respect to the presence or absence of activating mutations in KRAS in the tumor itself. Tumor KRAS status was ascertained in more than 90% of the 1,183 patients enrolled in the trial, said the company.

Importantly, in patients with tumors harboring activating KRAS mutations, PFS was significantly inferior in the Vectibix arm.

Roger Perlmutter, executive vice president of R&D at Amgen, said: We believe that these data document an important advance for patients with metastatic colorectal cancer. These are the first prospective Phase 3 data to demonstrate the utility of KRAS mutational analysis as a predictive biomarker.

Our study underscores the importance of KRAS status in identifying the appropriate patient population to be treated with Vectibix, consistent with worldwide labeling, he added.

Not only is the improvement in progression-free survival limited to patients with wild-type KRAS tumors, but patients with KRAS mutant tumors were negatively affected when Vectibix was added to a standard chemotherapy regimen. We believe Vectibix should not be used in patients with tumors containing activating KRAS mutations, Mr. Perlmutter concluded.