Combining abiraterone with androgen deprivation therapy (ADT) for men with locally advanced or metastatic prostate cancer (PCa) initiating long-term hormone therapy improves overall survival by 37%, researchers reported at the 2017 American Society of Clinical Oncology in Chicago and published in the New England Journal of Medicine.
The finding, from the STAMPEDE trial (NCT00268476), may change the standard of care.
“These are the most powerful results I’ve seen from a prostate cancer trial — it’s a once in a career feeling. This is one of the biggest reductions in death I’ve seen in any clinical trial for adult cancers,” lead investigator Nicholas James, PhD, of the University of Birmingham in the UK, said in a press release.
During 2011 to 2014, Dr James and his colleagues randomly assigned 957 men to ADT alone and 960 men to a novel combination of ADT plus abiraterone acetate (1000 mg daily) and prednisolone (5 mg daily). The vast majority (95%) of patients (median age 67; median PSA 53 ng/mL) were newly diagnosed and the remainder had PCa relapse. Overall, 52% of patients had metastatic disease and 48% non-metastatic disease (20% node-positive or node-indeterminate and 28% node-negative). Among non-metastatic PCa patients, local radiation treatment was required for negative nodes and recommended for positive nodes. ADT was administered for 2 years or disease progression.
Over a median of 40 months, 262 men in the ADT-alone group and 184 in the combination group died. The combination arm experienced significant benefit with treatment compared with the ADT-alone arm (3-year overall survival 83% vs 76%; 3-year failure-free survival 75% vs 45%; and 3-year progression-free survival 80% vs 62%).
“Abiraterone is already used to treat some men whose disease has spread but our results show many more could benefit,” Dr James stated. “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.”
According to the investigators, adverse events were consistent with experience for castration-resistant prostate cancer.
1. James ND, de Bono JS, Spears MR, et al. Abiraterone for Prostate Cancer Not Previously Treated with Hormone Therapy. New Eng J Med. ASCO Abstract LBA5003.
2. Adding abiraterone to standard treatment improves prostate cancer survival by 40 percent. Cancer Research UK; June 3, 2017. [news release]