Merck KGaA has been boosted by the news that its oncology agent Erbitux can now be used in Japan in combination with chemotherapy in the first-line-treatment for patients with colorectal cancer carrying the KRAS wildtype gene.

The approval of this extended usage for Erbitux (cetuximab) was granted following submission of data from the Phase III CRYSTAL trial to Japan's Pharmaceutical and Medical Devices Agency. That data demonstrated a significant overall survival advantage for patients who were treated with Erbitux in combination with FOLFIRI (infusional 5FU and irinotecan) compared to those who received chemotherapy alone. In addition, an updated analysis showed that the combo also significantly reduced the risk of disease progression by 30% and increased the tumour response rate.

Wayne Paterson, managing director of the Merck Serono unit in Japan, said that the “striking improvement in response rates…is of vital importance”, while high response rates mean significant tumour shrinkage and “increased opportunities for complete removal of the tumour and a higher potential for the disease to be cured”. He added that “this is of particular value in a country where cure rather than palliation is a primary treatment objective”.

The incidence of colorectal cancer in Japan has increased nearly five-fold in the last 25 years, Merck noted, mainly due to westernisation of the diet. With more than 95,000 new cases reported in the country in 2002, it has become the most common cancer among women and the second most common among men, after stomach cancer.

In Japan, Merck receives 50% of the profits from Erbitux, while partners ImClone (now owned by Eli Lilly) and Bristol-Myers Squibb each receive 25%.