Trials show that Merck KGaA’s newly launched cancer drug Erbitux slows the spread of rectal and Colon cancer and enables more patients to have surgery, the German drug and chemical company said late on Saturday.

Erbitux, in combination with other standard anti-cancer drugs, delayed disease progression by an average of 12.3 months in patients with metastatic Colorectal cancer, Merck said in a presentation to a U.S. medical conference in Orlando, Florida.

It also allowed nine out of 42 patients with previously inoperable cancers to receive surgery, which typically improves patients’ chances of living another five years from less than 5 percent to 50 percent.

“Although only a small population of patients has been studied, results underline the huge potential of Erbitux,” researcher Eric Van Cutsem from University Hospital Gasthuisberg in Leuven, Belgium said in the statement.

“For patients with unresectable metastases, it is (currently) unlikely we can offer a curative option. Any advance which brings us closer to this potential is urgently needed,” Van Cutsem added.

Merck added that the trials were at intermediate ‘phase II’ stage, involving fewer patients than final ‘phase III’ trials.

The drug’s side effects included skin rashes, but Merck described Erbitux’s overall safety profile as favorable.

Merck has a license from the drug’s inventor, ImClone Systems Inc, to market Erbitux outside the United States and Canada and has regulatory approval to market the drug in the European Union and elsewhere in Europe, Asia and Latin America.

Merck first launched the drug in 2004, and sales have risen rapidly to 42 million euros ($54.0 million) in the first quarter of 2005 from 36 million euros in the final quarter of 2004.

ImClone previously reported $87.1 million in first-quarter Erbitux sales, below analysts’ expectations.