Announced by researchers at a cancer conference in Chicago, the new findings show earlier and combined use of existing treatments can have a significant impact on advanced disease, but questions remain about its suitability for all men.
The latest results from the extensive STAMPEDE trial, announced today at the American Society of Cancer Oncology (ASCO) conference in Chicago, show that adding abiraterone to hormone therapy improves survival for men with advanced prostate cancer compared to hormone therapy alone.
Almost 2,000 men were involved in this particular arm of the STAMPEDE trial, with 83% of those receiving abiraterone alongside androgen deprivation therapy (ADT) surviving for over three years, compared to 76% of men who received ADT alone.
Abiraterone is a new type of hormone treatment that is given to men with advanced prostate cancer once their cancer has become resistant to ADT. Today's results suggest giving abiraterone earlier in the treatment pathway could increase how effective it is. However, it's not clear how much this would benefit men in reality, as clinical practice for treating advanced prostate cancer has changed since the trial began.
Following the STAMPEDE trial results from 2015, which showed giving the chemotherapy drug, docetaxel, at the same time as ADT helped men survive for an average of 15 months longer than ADT alone, earlier docetaxel quickly became the standard treatment option for men with advanced prostate cancer on the NHS.
As docetaxel and abiraterone have not been compared side-by-side, we can't say yet which is better. Even more importantly, we need a way to find out if they will work differently in different men, or if they might work even better together.
Dr Iain Frame, director of research at Prostate Cancer UK, said: “These results are further evidence that earlier, combined use of existing treatments can improve the survival of men diagnosed with advanced prostate cancer. The potential benefits of giving some men abiraterone alongside hormone therapy are clearly impressive, and we will be working with all relevant bodies to make sure this treatment becomes an option available for these men via the NHS.
“However, there are still key questions that need to be answered. Critically, we need to determine which men will gain the most benefit from this treatment combination and which men will respond better to earlier use of other treatments, such as docetaxel. This knowledge will be crucial in enabling men and clinicians to make more informed treatment choices, ensuring that men are receiving the right treatments for them, at the right time.”
“If we want to dramatically improve survival of all men with advanced prostate cancer, we must move towards this kind of personalised approach to treatment. Prostate Cancer UK is committed to funding the research that will make sure that this happens.”
Prostate Cancer UK is already developing a test to see which men will benefit from abiraterone, as we know that a third of men do not respond to the drug after ADT. This is part of a large effort towards precision medicine, where each man gets a treatment based on the genetic makeup of his cancer. We are committing £1.4 million to a grant to support this area of research.
Men who cannot receive chemotherapy such as docetaxel could benefit most from this new research into abiraterone. However, this will require a change in licensing before doctors would be able to prescribe it alongside ADT.
One of the men who took part in the trial was Kevin Hughes [pictured with his granddaughters above].
“I was diagnosed with advanced prostate cancer in 2013, aged 57,” says Kevin. “I didn’t have any symptoms, but my PSA levels were in the 500s. At the time, I was told I’d likely only have about three years to live, which was devastating. But I was determined to give it everything I had.
“I was then told by my doctor I may be eligible to be part of the STAMPEDE trial. The results were really brilliant. Since my diagnosis, I’d been keeping a chart of all my PSA results and the graph fell dramatically once I started on the abiraterone, too. My PSA went down to 0.01. This was great to see, I can tell you.
“I’m now four years since my diagnosis and things are going really well.”
It's important we fully understand how earlier use of abiraterone will benefit men with advanced prostate cancer and if this outweighs the side effects from the drug. Severe side effects, such as hypertension and liver problems, were reported by 41% of men taking abiraterone in the STAMPEDE trial, compared to just 29% in the control group receiving just ADT.
The findings were published in the New England Journal of Medicine and we're expecting results from another similar trial, known as LATITUDE, to be announced on Sunday that was conducted by the pharmaceutical company that owns abiraterone. We'll have more analysis of these and the STAMPEDE trial's results early next week.