A new drug for prostate cancer could extend the lives of thousands of men.
About 12,000 men a year with aggressive prostate cancer reach a point where standard medications no longer work for them.
Now scientists have found a treatment for these men that could shrink the tumors by more than 30 percent, an early-stage study suggests.
Many men with prostate cancer take pills such as enzalutamide, which prevent testosterone from helping tumors grow in their bodies.
But aggressive prostate cancer finds a ‘plan B’ and replaces testosterone with a different kind of fuel, causing the drugs to stop working.
Scientists have found a drug that can shrink some tumors by 30 percent, but it only works in a quarter of men
Scientists now believe this Plan B fuel consists of white blood cells, which are hijacked by tumors to help them grow.
An experimental drug used to prevent tumors from hijacking white blood cells was given to 21 men with aggressive, advanced prostate cancer.
Among the volunteers, one man saw tumors in his prostate shrink by more than 30 percent.
The treatment showed signs of success in five of the men, all of whom had incurable prostate cancer but survived for more than six months without their cancer worsening after receiving the treatment.
Researchers plan to recruit more men to find out exactly how much extra time with their families the treatment could buy patients with aggressive prostate cancer.
After discovering that the experimental drug only helped a quarter of men, perhaps because some people’s white blood cells are genetically different and harder to target, the scientists are also working on a better version of the drug.
They hope it could help people with other types of cancer, such as breast cancer, which can also use white blood cells as backup fuel instead of estrogen, making standard medications ineffective.
Professor Johann De Bono, senior author of the study from London’s Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, said: ‘This research proves for the first time that targeting myeloid cells rather than the cancer cells themselves can can be reduced and benefit patients. .
‘This is hugely exciting and suggests we have a completely new way to treat prostate cancer.’
Scientists hope the drug could help people with other types of cancer, such as breast cancer, where white blood cells can also be used as backup fuel instead of estrogen.
The new study, published in the journal Nature, comes more than a decade after scientists discovered that men with aggressive prostate cancer had higher levels of certain immune cells in their blood.
These cells, called myeloid white blood cells and made in the bone marrow, are normally used to fight infections or heal wounds.
But prostate cancer can apparently cause them to completely change their behavior, so they instead invade tumors to help them grow and spread.
After discovering this alternative fuel for prostate cancer and blocking it in mice, scientists tested their experimental drug, called AZD5069, in humans.
The drug prevents white blood cells from being drawn into prostate tumors by blocking the ‘doorway’ on their surface, which is targeted by chemical signals from the tumors.
Of the five men who responded to the treatment, one saw his tumor shrink, while in the rest the cancer appeared to have stopped.
After receiving AZD5069, in combination with enzalutamide, to prevent testosterone from fueling their cancer, men had lower numbers of cancer cells in their blood and lower levels of a protein called PSA, which is elevated in men with prostate cancer.
Dr. Matthew Hobbs, research director at Prostate Cancer UK, which co-funded the study with Cancer Research UK, said: ‘I am hugely excited by these results and proud that we are funding such revolutionary research.
‘Now we want pharmaceutical companies to work with researchers to develop new drugs based on what we’ve learned and test them in larger studies, making research a reality for men.’
The Daily Mail has relaunched its End the Needless Prostate Deaths campaign this year in a bid to improve the diagnosis and treatment of prostate cancer, which kills more than 11,500 men in Britain every year.