AstraZeneca's olaparib looks promising for a targeted set of prostate cancer patients

AstraZeneca's headquarters in London--Courtesy of AstraZeneca

Scientists in the U.K. say that AstraZeneca's ($AZN) drug olaparib, approved by the FDA late last year to treat ovarian cancer and sold as Lynparza, has demonstrated distinct signs of efficacy in a small and very targeted group of prostate cancer patients who share a distinct type of genetic mutation.

Olaparib is a poly ADP-ribose polymerase (PARP) inhibitor, which blocks enzymes involved in DNA repair. It's used among women suffering from ovarian cancer who have BRCA gene mutations identified through a genetic test.

The team of researchers from the Institute of Cancer Research in London and The Royal Marsden NHS Foundation Trust recruited 49 treatment-resistant, metastatic prostate cancer patients and tested the drug on them. What excited them was that 14 of the patients who responded to the drug also had genetic mutations linked with DNA repair, a profile shared by 16 patients.

"This trial is exciting because it could offer a new way to treat prostate cancer by targeting genetic mistakes in cancers that have spread," noted Áine McCarthy, the science information officer at Cancer Research UK, which helped fund the work, in a statement. "The hope is that this approach could help save many more lives in the future." The results were published in The New England Journal of Medicine.

One of the scientists involved, Joaquin Mateo, told BBC News that the drug "is very promising. Those entering the trial had an expected survival of 10 to 12 months and we have many patients on the drug for longer than a year."

First, though, the researchers will run a trial that consists entirely of prostate cancer patients with the same type of genetic defects.

ICR's Professor Johann de Bono said he hoped that their work paves the way for genetic testing of all prostate cancer patients, with this drug emerging as a standard therapy in the patient group.

Ironically, the drug is being studied in the U.K. but isn't available to ovarian cancer patients in the country. Government regulators have objected to the price AstraZeneca has put on it.

- here's the release
- read the journal article