Hope for prostate cancer ‘cure’ as trial finds ‘precision’ drug can help incurable patients live almost four months longer
Thousands of men with advanced prostate cancer could live for longer by taking a ‘precision’ drug, a major trial has suggested.
Lynparza extended the lives of men with an incurable form of the disease, which is resistant to standard treatment. The medication froze the disease progression by an average of 7.4 months – more than double that of hormone treatment currently used.
Men on the drug, also known as Olaparib, lived for 18.5 months – about 3.5 months longer than treatment used on the British National Health Service (NHS). It is the first proven drug for prostate cancer that can be personalised to a patients’ genetic makeup, rather than using a one-size-fits all approach.
Olaparib – already used around the world and on the NHS for ovarian cancer – works by targeting faulty DNA, which help cancer cells, repair and thrive.
Scientists have said the results were a ‘remarkable achievement’, and could improve the lives of up to 10,000 British men.
Lynparza is intended to treat men whose cancers don’t respond to other therapies. Their cancer continues to grow and spread, which is eventually fatal.
This is called metastatic castration-resistant prostate cancer (mCRPC). Scientists say there is a growing need for new and effective therapies for these patients.
It affects around 10 to 20 per cent of prostate cancer patients within five years of their diagnosis – equal to between 4,000 and 10,000 men per year in the UK.
AstraZeneca, the manufacturer of Lynparza, ran the trial of the drug alongside US pharmaceutical company MSD, or Merck.
The phase three trial of the drug, called PROfound, was led by scientists from the Institute of Cancer Research in London and Northwestern University in Chicago.
They compared Lynparza – the branded name of the drug olaparib – with standard hormone treatments on the NHS, abiraterone and enzalutamide.
Disease progression was halted for 7.39 months in men taking Lynparza, compared to 3.55 months with hormonal treatment.
Men lived for 18.5 months when treated with Lynparza, compared to 15.1 months with hormone treatment.
Treatment with Lynparza resulted in a 66 per cent greater delay in progression than the hormonal agents, the results also showed.
Dr. Eleni Efstathiou, MD Anderson Cancer Center, Houston, said: “This is impressive because it is considerably higher than the 35-40 per cent improvements with which we’ve been very satisfied in previous prostate cancer studies in this more advanced disease setting.
“There is a trend towards improved survival, but we need to wait for the final analysis.”
Study author Professor Maha Hussain, Northwestern University, said: “To see such a significant effect on disease progression and other clinically relevant effects such as pain progression and objective response rate is a remarkable achievement.
“We saw the benefits of olaparib in all sub-groups of patients, regardless of country, age, prior therapy and severity of disease, including in those with worse disease that had spread to their liver or lungs.”
Lynparza works by targeting mutated BRCA genes – of which some of the men in the study have.
Men with a broader range of less well studied faulty DNA repair genes were also studied in the trial with similar results.
Cancer cells with a change in their genes rely on a protein called PARP, which helps damaged cells to repair themselves. Lynparza blocks PARP, leading to the cancer cells dying.
Hormonal treatment, on the other hand, lowers testosterone, the male sex hormone, which many prostate tumours thrive off.
When a man is diagnosed with prostate cancer, he may be given surgery, radiotherapy, chemotherapy or hormonal treatment.
But if the cancer spreads to other parts of the body and cannot be cured, treatment is focused on prolonging life and relieving symptoms.
Lynparza may work for men whose cancers have continued to grow and spread even when their testosterone levels are medically reduced.
Nearly six years ago retired lecturer Clive Chivers was diagnosed with prostate cancer.
The married father-of-two from Colchester, Essex, puts his continued survival down to his inclusion on a trial for the breakthrough drug olaparib.
Doctors initially tried hormone treatments and four rounds of chemotherapy but the tumours kept growing.
In May 2017 the Royal Marsden cancer hospital in London suggested he join a trial of olaparib. They saw an immediate response.
“My PSA levels went down and it shrank the growths that had spread outside the prostate,” Mr. Chivers, 73, said. “Olaparib has kept me going for almost two years. Although there was one lesion on my spine that didn’t respond to the drug, it was working otherwise,” he said. “The treatment I received has been amazing.”
Professor Hussain said: “Prostate cancer has lagged behind all other common solid tumours in the use of molecularly targeted treatment so it is very exciting that now we can personalise an individual’s treatment based on specific genomic alterations in their cancer cells.”
The only down side of the findings, is that side effects, such as anaemia and nausea, were more common in those taking Lynparza.
A total of 16.4 per cent of patients taking Lynparza discontinued treatment due to adverse events, compared to 8.5 per cent with hormonal treatment.
Efstathiou said: “Overall, these data show that, like breast and lung cancers, prostate cancer is not one but many different diseases and we need to start identifying different groups of patients and treating them with targeted therapy.”