Offering a drug up-front with standard hormone treatment extends survival in men whose prostate cancer has spread, according to results from a late stage clinical trial.
The results, to be presented at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, show that adding the drug abiraterone (Zytiga) to hormone therapy lowered the risk of death in men whose disease had spread at the time of diagnosis.
The combined treatment also more than doubled the time before patients’ disease worsened, according to results that have been published in the New England Journal of Medicine.
“The benefit from early use of abiraterone we saw in this study is at least comparable to the benefit from docetaxel chemotherapy, which was observed in prior clinical trials, but abiraterone is much easier to tolerate, with many patients reporting no side effects at all,” said lead study author Dr Karim Fizazi, head of the Department of Cancer Medicine at Gustave Roussy in Paris.
Professor Rob Jones, an expert in prostate cancer at the Cancer Research UK Beatson Institute, said that if the combined treatment is approved for use on the NHS it could improve the quality of life for thousands of men.
Abiraterone is already approved for use on the NHS in men whose prostate cancer has become resistant to hormone treatment.
The phase III LATITUDE trial included men with prostate cancer that had already spread at the time of diagnosis, but who had yet to receive hormone treatment. It compared patients treated with standard hormone therapy to those treated with hormone therapy plus abiraterone and the steroid prednisone.
After an average follow-up of 2 and a half years, men treated with abiraterone were more likely to be alive than those who received hormone treatment alone.
The average time before the disease worsened was also extended in those treated with abiraterone, from 14.8 months in patients treated with hormone therapy to 33 months in those receiving the combined treatment.
“The time for which the cancer remained under control was more than twice as long for men receiving abiraterone,” said Jones.
“It also took longer for the pain experienced by these patients to get worse – a very common problem with this disease.
“From our own experiences with abiraterone, we know that it is generally very well tolerated with few side effects. Once available, this treatment will enable thousands of men every year in the UK to survive longer at a stage of the disease where it is, by and large, not interfering with their ability to enjoy a normal, or near-normal, quality of life.”
Results of a second trial to be presented at the conference, supported by Cancer Research UK and also published in the New England Journal of Medicine, show similar results for the combined treatment.
The phase III STAMPEDE trial found that adding abiraterone to hormone therapy at the start of treatment for prostate cancer improves survival by 37%.
Experts believe these results could change the standard of care for these men.
“Abiraterone is already used to treat some men whose disease has spread but our results show many more could benefit,” said Professor Nicholas James, who leads the STAMPEDE trial.
“In addition to the improvements in survival and time without relapse, the drug reduced the rates of severe bone complications, a major problem in prostate cancer, by more than a half.
“I really hope these results can change clinical practice.”
LATITUDE: A phase III, double-blind, randomized trial of androgen deprivation therapy with abiraterone acetate plus prednisone or placebos in newly diagnosed high-risk metastatic hormone-naive prostate cancer. 2017 ASCO Annual Meeting.