Gene-targeted drug effective at treating prostate cancer: study

A gene-targeted drug for women with inherited cancers can also treat men with advanced prostate cancer, a new clinical trial concluded Wednesday.

Olaparib, the world's first marketed drug against inherited cancer mutations, was licensed last year by the U.S. Food and Drug administration for women with ovarian cancer who have inherited BRCA mutations.

The new trial, published in the New England Journal of Medicine and described as a "milestone" by the London-based Institute of Cancer Research, found it can benefit patients with treatment-resistant, advanced prostate cancer.

Of the 49 patients who received olaparib, 16 of them -- or 33 percent -- responded. Their tumor growth stopped, with lasting falls in the levels of prostate specific antigen, falls in circulating tumor cell counts in the blood, and radiological responses on CT scans and MRI.

Those whose prostate cancers have defects in their systems for repairing DNA responded particularly well to the drug.

Of the 16 patients with detectable DNA repair mutations, 14 responded very well to olaparib, accounting for the large majority of those who benefited from the drug.

The results have led on to the start of TOPARP-B, a second part of this trial, in which only men whose prostate cancers have detectable DNA repair mutations will receive olaparib.

"Our trial marks a significant step forward in the treatment of prostate cancer, showing that olaparib is highly effective at treating men with DNA repair defects in their tumors," trial chief investigator Professor Johann de Bono, head of drug development at the Institute of Cancer Research, said in a statement.

"I hope it won't be long before we are using olaparib in the clinic to treat prostate cancer, or before genomic stratification of cancers becomes a standard in this and other cancers." Endit