European authorities on May 25th recommend against approval of Amgen's biologic drug Vectibix for treating metastatic colorectal cancer in patients who have failed chemotherapy, concluding that the data submitted did not show that the biologic's benefits outweighed the risks.

The European Medicines Agency's Committee for Medicinal Products for Human Use said the way the main clinical trial was designed, there was not enough evidence to show a benefit of Vectibix.

The European Commission generally follows the recommendation of the CHMP.

Amgen said in a statement it intended to appeal the decision, and said it felt "the available data demonstrates that Vectibix improves progression-free survival for [advanced colorectal cancer] patients who have progressed on, or following . . . chemotherapy regimens.

The drug was approved in September 2006 in the U.S. for treatment of patients with advanced colorectal cancer whose disease has progressed after chemotherapy, and Amgen hopes to eventually market Vectibix earlier in the treatment process.

But Vectibix suffered a setback in March when a study of use of the biologic in combination with chemotherapy and Avastin showed the drug was associated with a shorter survival time compared to people not taking Vectibix.

In the early weeks of the trial submitted to European regulators, many of the patients originally receiving best standard care alone started to receive Vectibix after their disease had got worse, making it difficult to compare the effects of Vectibix and standard care, the CHMP said.

Vectibix also had a very small effect in increasing the time until the disease got worse or the patient died, according to the CHMP. And other studies showed that patients receiving Vectibix had increases in side effects, resulting in poorer quality of life.