A hi-tech prostate cancer drug that offers hope to men who have run out of treatment options became available in the UK on Thursday.
Enzalutamide is licensed for patients with advanced prostate cancer who are no longer responding to hormone treatments or chemotherapy.
Data from a major trial showed that the new pill, costing around £2,500 a month, can extend the lives of patients no longer being treated by almost five months.
Seven out of 10 of the men in the Phase III Affirm trial taking enzalutamide were still alive after one year.
The drug, previously known as MDV3100 and now marketed under the brand name Xtandi, blocks molecular signals that allow the male hormone testosterone to fuel prostate cancer.
It targets three different steps of the signalling pathway.
Professor Johann de Bono, from the Institute of Cancer Research in London, who led the Affirm trial, said: "Enzalutamide is a much needed development in prostate cancer treatment and will provide a new option for the increasing number of men with advanced prostate cancer in the UK whose disease has become resistant to first-line hormonal treatments and who have had docetaxel chemotherapy.
"Enzalutamide has already demonstrated a positive impact on quality of life whilst increasing the life-span of patients with this common disease.
"It's use will bring significant benefits, establishing it as a key component of advanced prostate cancer treatment in the UK."
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Almost 2,000 men took part in the Affirm trial, all of whom had previously undergone chemotherapy.
Half were given enzalutamide and half a non-active placebo.
A major advantage of enzalutamide over other treatments is its relative lack of side effects.
Dr Heather Payne, consultant oncologist at University College London Hospitals, said: "The launch of Xtandi represents a major advance in the treatment of patients with advanced prostate cancer.
"One of the biggest challenges in cancer medicine is managing the side effects that come with treatment, so it is remarkable to find a new therapy which makes patients' feel better.
"Extending patients' lives at this stage of their disease is our primary aim, but it's incredibly important to balance this with the impact treatment may have on patients' quality of life."
Drew Lindon, from the charity Prostate Cancer UK, said: "It is excellent news that enzalutamide can now be prescribed for the treatment of men in the UK with advanced prostate cancer for whom chemotherapy is no longer working.
"For some men, this drug could offer precious extra time with loved ones, and will be a welcome addition to what is currently a very limited armoury.
"However, although enzalutamide can now be prescribed by doctors, a man's local NHS health provider is not obliged to pay for it.
"And while men in England can apply for access through the Cancer Drugs Fund, others living elsewhere in the UK could be left at a disadvantage.
"We urge NICE (National Institute for health and Clinical Excellence) and the Scottish Medicines Consortium to appraise this drug swiftly, and the pharmaceutical company to set a reasonable price, in the hope that it will soon be recommended and routinely available on the NHS for all those men who need it."