Data from the final analysis of the Phase 3 study COU-AA-302 have shown that Zytiga® (abiraterone acetate) plus low dose prednisolone significantly prolongs overall survival (OS) with a median life extension of 4.4 months among men with metastatic castration resistant prostate cancer (mCRPC) who have not previously been treated with chemotherapy (median OS, 34.7 vs 30.3 mos with placebo plus prednisolone; HR=0.81 [95% CI, 0.70-0.93]; p=0.0033), after a median follow-up of more than four years (49.2 months). (1)
Data from the final analysis of the Phase 3 study COU-AA-302 have shown that Zytiga® (abiraterone acetate) plus low dose prednisolone significantly prolongs overall survival (OS) with a median life extension of 4.4 months among men with metastatic castration resistant prostate cancer (mCRPC) who have not previously been treated with chemotherapy (median OS, 34.7 vs 30.3 mos with placebo plus prednisolone; HR=0.81 [95% CI, 0.70-0.93]; p=0.0033), after a median follow-up of more than four years (49.2 months). (1)
The final analysis, presented at the European Society for Medical Oncology (ESMO) conference in Madrid, is the first to demonstrate a statistically significant improvement in OS in this study. This is particularly noteworthy as men in both treatment arms received other subsequent therapy, including the 44 percent of men in the placebo plus prednisolone arm who subsequently received abiraterone plus prednisolone. The treatment effect with abiraterone was more pronounced when adjusting for 44 percent of prednisolone patients who crossed over to abiraterone (HR = 0.74). (1)
Commenting on the study results, Dr Alison Birtle, Consultant Clinical Oncologist at the Rosemere Cancer Centre, Royal Preston Hospital, said: “This study has previously shown that abiraterone provides an effective treatment option for patients with metastatic, hormone-resistant, disease who wish to delay or avoid chemotherapy. It has now shown that treatment with abiraterone can also add more than four months additional survival in these patients. The availability of a treatment option that can both maintain quality of life and also increase survival is a very welcome development.”
The final analysis also showed a significant improvement in time to opiate use among those in the abiraterone arm versus placebo (33.4 vs 23.4 mos; HR=0.72 [95% CI, 0.61-0.85]; p=0.0001). With two additional years of follow-up since the last clinical cut- off (median 49.2 months), the safety profile of abiraterone remained unchanged, with no observed change in low dose prednisolone-related toxicity. Side effects were more common in the abiraterone arm versus placebo, with the most commonly reported grade 3/4 adverse events being: hypertension (4.6% vs 3.1%), hypokalemia (2.6% vs 1.9%), liver toxicities (increased alanine aminotransferase (ALT), 5.9% vs 0.7%) and increased aspartate aminotransferase (AST) (3.3% vs 0.9%), and fluid retention/oedema (1.1% vs 1.7%). (1)
Dr Peter Barnes, Medical Director at Janssen, commented: “These data demonstrate clearly the clinical value of abiraterone to this group of patients. We continue to work closely with NICE and the Department of Health with the aim to have this medicine routinely available on the NHS.”
In August the NICE Final Appraisal Determination (FAD) on the use of abiraterone before chemotherapy did not recommend the medicine at this stage of the disease. In September NICE suspended the appraisal to allow Janssen to submit an amended patient access scheme to the Department of Health. This proposal is currently before the Department of Health for consideration.
Regulatory authorities in both Europe and the United States approved abiraterone acetate for use before chemotherapy in December 2012. (2) Since then it has been prescribed to slow the progression of the disease and delay the need for chemotherapy in many thousands of patients across Europe and the United States, and has become the second most requested treatment on the NHS Cancer Drugs Fund (CDF). (3)
Abiraterone was discovered in the UK, and its use around the world as a mainstream treatment represents a major success story for the UK life sciences industry.
References:
- Ryan, CJ, et al. Abstract 5936 presented at ESMO 2014, Madrid, Spain.
- Zytiga SPC. Available at: https://www.medicines.org.uk/emc/medicine/24976/SPC/Zytiga+250+mg+tablets/ (accessed 23 September 2014)
- NHS England, The Cancer Drugs Fund http://www.england.nhs.uk/ourwork/pe/cdf/ (accessed 23 September 2014)
