FRANKFURT, June 1 (Reuters) - Merck KGaA's cancer drug Erbitux was shown to be more effective at prolonging the lives of bowel cancer patients than Roche's Avastin, Merck said.
In a drug trial, the two drugs were each given in combination with Folfiri chemotherapy to patients whose colorectal cancer had started spreading to other organs. The results showed the Erbitux group survived on average nearly four months longer than the Avastin group.
The trial was conducted by an independent research collaborative of the German Association of Medical Oncology (AIO) and sponsored by Germany's Merck.
Only patients whose tumors contain the normal, or wild-type, version of a gene called KRAS took part in the trial. Erbitux is only approved in this patient subgroup, which accounts for about 60 percent of colorectal cancer cases.
The trial data presented at the American Society of Clinical Oncology in Chicago this weekend showed that overall survival was a median 28.7 months in the Erbitux arm and 25 months in the Avastin arm.
There was little difference, however, between the two groups in how long it took before the disease got worse, so-called progression-free survival, which was about 10 months for both.
Merck declined to comment on the additional sales potential from the results.
Both drugs are approved and are in use as initial treatments of metastatic bowel cancer in combination with chemotherapy and the findings could translate into more prescriptions of Erbitux at the expense of Avastin in the wild-type KRAS patient group.
Volker Heinemann, oncology professor at Munich University and the study's principal investigator, said the results suggest that Erbitux should be given preference over Avastin for the patient group in question while Avastin should be given to patients who could not be helped by Erbitux.
Germany's Merck has the marketing and development rights to Erbitux outside North America, while Bristol-Myers Squibb sells the product in North America with Eli Lilly receiving royalties.
Merck had 887 million euros ($1.15 billion) in Erbitux sales last year, from head and neck as well as bowel cancer, while Bristol-Myers Squibb generated $702 million in sales from the drug.
Roche posted 5.76 billion Swiss francs ($6.00 billion) in Avastin sales last year.