German chemical and pharmaceutical group Bayer said Monday that its Alpharadin treatment for prostate cancer has shown positive results in advanced trials.
Bayer developed Alpharadin with the Norwegian lab Algeta and tested it on 922 people in Phase III trials, a statement said.
Those on the treatment lived an average 14 months after the course began, compared with an average of 11.2 months for those given a placebo, it added.
The tests were abandoned early to allow the latter to be given Alpharadin as well.
It has not yet been approved for general sale but Bayer has placed strong hopes in the compound, radium-223 chloride, which attacks cancer cells in bones.
"Around 90 percent of men with advanced prostate cancer have bone metastases which are the main cause of disability and death in this disease," the statement said.
Prostate cancer is the most frequent form of cancer among men in Northern Europe and the United States. In 2008, an estimated 903,000 men had prostate cancer worldwide and 250,000 died from the disease, Bayer said.
The news was welcomed on Frankfurt's stock exchange, where Bayer shares gained 1.98 percent to 56.53 euros to lead gainers on the DAX index which was 0.27 percent lower overall.