Scientists are confident that olaparib will be a breakthrough drug for patients who have cancer cells with defective DNA repair genes because it prevents them from repairing themselves and ultimately kills them without damaging healthy cells.
Almost a third of men with aggressive prostate cancer are expected to benefit from olaparib, which surpasses the hormone treatments currently available to slow the progression of the disease.
It is the first drug of its kind that is genetically targeted and could be available via the NHS in as little as two years, with the United States and Europe expected to approve it as a treatment this year.
Prostate cancer is the most common cancer in men, with around 48,000 cases diagnosed each year in the UK.
Professor Johann de Bono of the Institute of Cancer Research in London and consultant to the Royal Marsden NHS Foundation Trust, who co-led the study, said it was exciting to see a drug that had helped women with ovarian and breast cancer “obvious benefits” for prostate cancer patients.
“I look forward to seeing this drug begin to reach men who may benefit from it on the NHS – hopefully in the coming years,” he said.
“Next, we will assess how to combine olaparib with other treatments, which could help men with prostate cancer and defective DNA repair genes live longer. “
The final results of the PROfound trial, funded by AstraZeneca, were published in the New England Journal of Medicine on Tuesday.
It is the culmination of a decade of research supported by Prostate Cancer UK, the Prostate Cancer Foundation and Movember.
A team from the Institute of Cancer Research and the Royal Marsden NHS Foundation Trust worked with colleagues around the world to conduct the trial of 387 men with advanced prostate cancer who had alterations in one or more several of the 15 DNA repair genes.
When these participants took olaparib, it significantly delayed the progression of their cancer. It took 5.8 months to get worse, compared to 3.5 months for those taking the already widely used hormone treatments, enzalutamide and abiraterone.
Men with defective BRCA1, BRCA2 or ATM genes benefited the most from receiving olaparib.
It took 7.4 months before their cancers progressed and their overall survival was 19 months on average, while those taking hormone treatments found that their cancers progressed after 3.6 months and their overall survival was 15 months on average.
Olaparib, which is given as a pill, has side effects, including anemia and nausea, but scientists believe it is much less stressful for the body than chemotherapy.
Professor Paul Workman, Director General of the Institute of Cancer Research, said: “These remarkable results mean that olaparib is now poised to become the first genetically targeted drug for the disease.
“The next step will be to find new ways to combine olaparib with other treatments to prevent or overcome drug resistance. “
Dr. David Montgomery, director of research at Prostate Cancer UK, added: “This exciting result represents a revolution in the treatment of prostate cancer. Until now, the treatment of men with advanced prostate cancer has been largely unique.
“This is why it is fantastic to see the publication of this study, which confirms the benefits of olaparib and its potential to be the first targeted treatment for prostate cancer.
“The results reinforce our commitment to ensuring that olaparib and its associated tests are available as soon as possible for men with advanced hormone-resistant prostate cancer. “