Mixed results for Amgen's cancer drug Vectibix

Amgen is continuing its push to boost Vectibix by narrowing the drug's target market. The drugmaker announced results from a another Phase III trial, this time evaluating Vectibix as a second-line treatment for patients with advanced colorectal cancer. In the latest study, Vectibix met only one of its primary endpoints. When combined with the FOLFIRI chemotherapy regimen, Vectibix delayed cancer progression in patients with tumors that carry normal or wild-type KRas genes. However, the drug failed to produce a statistically significant increase in overall survival.

The global trial involved 1,186 patients, more than 90 percent of whom were tested for KRas gene mutations. Patients with a mutated KRas gene experience more aggressive cancers and tend to have lower rates of survival. The combined treatment had no impact on the progression of cancer or overall survival of patients with a mutated KRas gene. "These results add to the growing body of evidence confirming the utility of KRAS as a predictive biomarker," Roger M. Perlmutter, Amgen's executive vice president, research and development, said in a statement.

Vectibix competes with Merck's blockbuster Erbitux and has not fared well. Vectibix brings in $150 million in sales annually, compared with $1.5 billion for Erbitux. Amgen has now completed two Phase III trials evaluating Vectibix as a first and second-line treatment in hopes of gaining a larger market share. The market responded with a mere sigh--the company's stock dropped 1 percent on the news, but has since risen. Detailed results of the study will be presented at a medical conference in Europe next month.

- here's the Amgen release
- the Forbes article