Prof David Webb, Professor of Clinical Pharmacology at the University of Edinburgh, said:

"This agent clearly looks promising, but it is still at the early stages of clinical development. It will be crucial to look carefully at the balance between its benefits and harms, before drawing firm conclusions about the usefulness of this new drug. Important side effects often only emerge with the larger clinical studies that now need to be done."

Prof Robert Souhami, Oncologist, said:

"The drug appears to differ from other anti-androgen treatments in that it blocks hormone production within the cancer itself as well as in normal tissues – which are the site of action of most of the usual hormone treatments for prostate cancer. This may account for its effectiveness in patients who have relapsed after receiving other anti-androgen treatments. Although these are interesting preliminary results its effect in improving survival can only be assessed in much larger studies."