Merck KGaA has been granted approval in Switzerland to expand the uses of its Erbitux (cetuximab) product to include the treatment of patients with head and neck cancer.

The approval by Swissmedic is the first in the world for this indication and means that Erbitux can be used alongside radiotherapy for patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN) which has not yet spread to other parts of the body. The drug is already approved to treat metastatic colorectal cancer.

The market for head and neck cancer treatments is underserved at present, with radiotherapy and older, more toxic chemotherapy drugs the only treatment options available. Analysts at Credit Suisse First Boston said earlier this year that adding the head and neck cancer indication to Erbitux could boost peak sales of the drug into the $1.5 billion dollar range.

In Europe alone, around 100,800 people are diagnosed with head and neck cancer and almost 40,000 die from the disease every year, according to Merck.

The registration is based upon results from a Phase III study which showed that Erbitux combined with radiotherapy improved median survival by 19.7 months compared with radiation alone.

Erbitux was originated by biotechnology firm ImClone Systems and is sold in the USA by Bristol-Myers Squibb. It brought in third-quarter revenues of $107 million for B-MS and 59 million euros ($70m) for Merck in the colorectal cancer indication. ImClone filed for approval of Erbitux in head and neck cancer in the USA in August, and an application in the European Union is also under review.