Abiraterone Combats Previously Untreatable Prostate Cancers
Tuesday 22 July 2008
New, groundbreaking research reveals that abiraterone, discovered at The Institute of Cancer Research, could treat up to 80 per cent of patients with aggressive and previously drug resistant prostate cancer, according to a study published in the Journal of Clinical Oncology (online 00:01 BST 22 July).
The results of the Phase 1 clinical trial, undertaken by The Institute of Cancer Research and The Royal Marsden Hospital and funded by Cougar Biotechnology, Inc.* found that the drug abiraterone could treat up to 10,000 British men diagnosed each year with the most aggressive and almost always fatal type of prostate cancer.
The study, involving 21 men, revealed significant tumour shrinkage and dramatic falls in PSA levels in the majority of advanced prostate cancer patients who received abiraterone.
Lead researcher Dr Johann de Bono said the drug abiraterone worked to block the generation of key hormones that drive the growth of prostate cancers.
"Clinical benefits included evidence of PSA falls and tumour shrinkage which was observed in 70-80 per cent of patients," he said.
"Abiraterone works not only in blocking the generation of these hormones in the testes, but also elsewhere in the body, including generation of hormones in the cancer itself.
"Tumour shrinkage was determined by a reduction in the blood level of prostate specific antigen (PSA) - a protein associated with prostate cancer activity, and also with analyses of CAT scans, MRI scans and bone scans.
"The Royal Marsden patients in this study have been monitored for up to two-and-a-half years and with continued use of abiraterone they were able to control their disease with few side-effects. A number of patients were able to stop taking morphine for the relief of bone pain.
"These men have very aggressive prostate cancer which is exceptionally difficult to treat and almost always proves to be fatal. We hope that abiraterone will eventually offer them real hope of an effective way of managing their condition and prolonging their lives.
"It is envisioned that abiraterone will be available for general use from 2011 and we hope it can become widely available. In the interim, it is available through clinical trials only."
Robin Wood, 65, from Wokingham near Reading was diagnosed with aggressive prostate cancer in May 2007 and failed to respond to treatment. He said: "My prostate was very cancerous and I had only a one in five chance of being alive by the end of 2008. However, abiraterone radically changed that, with my health improving within a week of beginning the drug trial. I have just returned from the huge Round The Island Yacht Race, which is a testament to my better health. I was diagnosed with prostate cancer after reading about the symptoms in the newspaper and immediately went to the GP. My life might have turned out very differently if I hadn’t read that article."
Simon Bush, 50, from London, was involved in the abiraterone clinical trial. He said: "Last year I was in severe pain because of my prostate cancer, which had worsened and spread to my bones. Chemotherapy and other treatments had failed and news that I had very few treatment options available to me was devastating for my family. Fitness and travelling were always my main interests and abiraterone has allowed me to have a year so far of near normality. The changes in my life have been dramatic, from managing thousands of people in a major bank, to facing a very uncertain future, then to renewed hope thanks to this drug trial."
All the patients involved in the trial had an aggressive form of prostate cancer in which the tumour tissue is believed to be able to produce its own supply of the hormones which drive tumour growth. This form cannot be solely treated with currently available drugs to block the production of male hormones by the testes.
Abiraterone works via a different mechanism which blocks the synthesis of male hormones in all tissues. Abiraterone may eventually be used alongside other treatments in patients with the "castration-resistant" aggressive form of the disease.
Abiraterone is owned by BTG and licensed to Los Angeles based Cougar Biotechnology, Inc. and is now undergoing further clinical trials. It is being used in a 1200-patient international study for the treatment of men with prostate cancer. Abiraterone is also being used to treat breast cancer in women through a Cancer Research UK funded trial.
Prostate cancer is the most common male cancer in the UK, with more than 35,000 new cases diagnosed annually. Around 10,000 men die of the disease every year, almost all of them from its castration-resistant form.
The Institute of Cancer Research Chief Executive Professor Peter Rigby said the discovery of abiraterone and its application to fighting prostate cancer, highlighted what could be achieved through funding world leading cancer research.
"Today we can reveal a potential major advance in the treatment of prostate cancer. We hope with the generous contribution of the community we can continue to develop better treatments to combat many cancers."
Cally Palmer, Chief Executive of The Royal Marsden NHS Foundation Trust, said: "The results of this study show just how important abiraterone is set to become in the treatment of men with prostate cancer and highlights the national importance of funding pioneering cancer research."
PLEASE NOTE: Patients who would like more information about becoming involved in the drug trial should speak to their consultant in the first instance. Their consultant will need to send a referral with a medical history to The Royal Marsden Hospital. Find out more about The Royal Marsden Hospital's referral process.
Patients who wish to be involved in the abiraterone clinical trial should talk to their urologist and have them provide a referral and medical records addressed to: Dr Johann de Bono, Royal Marsden Hospital Downs Road, Sutton, Surrey SM25P2
Notes to editors
*Cougar Biotechnology, Inc. was the major funder of the Phase 1 clinical trials, with the Medical Research Council, Experimental Cancer Medicine Centre and Cancer Research UK providing some funding.
- The paper, Phase 1 clinical trial of a selective inhibitor of CYP17, abiraterone acetate, which confirms that castration-resistant prostate cancer (CRPC) commonly remains hormone driven was published online in The Journal of Clinical Oncology on July 21.
- Clinical studies are ongoing in the effectiveness of abiraterone in the treatment of prostate cancer.
About The Institute of Cancer Research and The Royal Marsden Hospital
- The Institute of Cancer Research is Europe’s leading cancer research centre with expert scientists working on cutting edge research. It was founded in 1909 to carry out research into the causes of cancer and to develop new strategies for its prevention, diagnosis, treatment and care. For more information visit www.icr.ac.uk.
- The Institute is a charity that relies on voluntary income. The Institute is one of the world’s most cost-effective major cancer research organisations with over 95p in every £ of total income directly supporting research
- The Royal Marsden Hospital was the first hospital in the world dedicated to cancer treatment and research into the causes of cancer. A world leader in research, drug trialling and diagnostics, The Royal Marsden provides inpatient, day care and outpatient services for all areas of cancer treatment. The Royal Marsden is supported by its charity, The Royal Marsden Cancer Campaign.
- Today the hospital with its academic partner, The Institute of Cancer Research, forms the largest comprehensive cancer centre in Europe with more than 40,000 patients from the UK and abroad seen each year.