THE trail of a new drug for prostate cancer was halted in the UK because the results were too good.

Doctors at the Royal Marsden Hospital in London concluded that it would have been unethical not to offer it to all 922 cancer patients on the trial after the drug was shown to ease pain and cause only minor side-effects, The (London) Sunday Telegraph said.

The drug - Radium-223 Chloride, known as Alpharadin TM - targets tumours with alpha radiation, reducing the damage to surrounding tissue.

Dr Chris Parker, lead researcher on the project, said, "It's more damaging. It takes one, two, three hits to kill a cancer cell compared with thousands of hits for beta particles. They have such a tiny range, a few millionths of a meter. So we can be sure that the damage is being done where it should be."

Cancer patients on the new treatment have a 30 per cent lower death rate compared to those on placebo pills.

"It would have been unethical not to offer the active treatment to those taking placebo," Dr Parker said at the 2011 European Multidisciplinary Cancer Congress in Stockholm.

Read more at The Telegraph.