Amgen's Vectibix helps in 2nd line cancer therapy

* 2-month benefit for progression free survival in 2nd-line

* Vectibix is challenger for colon cancer drug Erbitux

BERLIN, Sept 22 (Reuters) - Amgen's AMGN.O colon cancer drug Vectibix helped patients live longer without their disease progressing when used as a second-line treatment, researchers told Europe's top cancer meeting on Tuesday.

Adding Vectibix to chemotherapy significantly improved progression-free survival in patients with an unmutated form of a gene by two months to 5.9 months compared to 3.9 months for those on chemotherapy only.

The study, a Phase III trial known as ‘181, showed there was no significant difference in overall survival but there was a greater than a three-fold improvement in the tumour response rate in patients on Vectibix -- 35 percent versus 10 percent.

“This a very, very high percentage in a population that has already been treated with chemotherapy,” said Marc Peeters of the University Hospital Ghent, the study’s principal investigator.

Amgen is also presenting data from a study looking at Vectibix as a first-line treatment -- an indication that drug companies are keen to develop in order present such medicines as not just a last resort.

An abstract made available at the ECCO-ESMO cancer congress on Monday from a study known as PRIME showed patients on Vectibix had a 1.6-month benefit for progression-free survival when given the drug as a first-line therapy. [ID:nLL733290]

Erbitux, discovered by ImClone which is now part of Eli Lilly LLY.N and is sold by Merck KGaA MRCG.DE and Bristol-Myers Squibb BMY.N, currently dominates the so-called anti-EGFR market. It had 2008 sales of $1.6 billion -- 10 times more than Amgen's AMGN.O Vectibix.

But Amgen hopes to redress this imbalance by showing its drug is similarly effective, while offering dosing advantages.

Both drugs have recently been found to work only in the 60-65 percent of patients whose tumours contain the normal, or wild-type, version of a gene known as KRAS. (Reporting by Ben Hirschler and Kate Kelland; Editing by Dan Lalor)