Astellas And Pfizer Present 5 And 8 Year Prostate Cancer Data Supporting XTANDI’s Survival Benefit

Astellas Pharma Inc. and Pfizer Inc. have announced positive long-term results from the Phase 3 ARCHES study extension, revealing that XTANDI™ (enzalutamide) combined with androgen deprivation therapy (ADT) continues to demonstrate a 30% reduced risk of death in men with metastatic hormone-sensitive prostate cancer (mHSPC) compared to ADT plus placebo. The five-year follow-up data showed consistent overall survival (OS) benefits across various patient subgroups, including those with high- and low-volume disease, and regardless of prior docetaxel treatment. The results will be presented at the ASCO Annual Meeting on June 3.

“Historically, the likelihood of survival at five years for men with metastatic hormone-sensitive prostate cancer was low, but with advancements in initial treatment intensification like what we’ve seen with XTANDI, this is now becoming the standard. In our five-year follow up of the global ARCHES trial, two-thirds of men are now surviving five years, representing a 13% absolute and 30% relative improvement over standard hormonal therapy alone, with benefits in patients with high and low disease burden that are meaningful to our patients” said Andrew J. Armstrong, MD, ScM, Director of Research at the Center for Prostate & Urologic Cancers, Duke Cancer Institute, Durham, NC, and ARCHES primary investigator. 

In parallel, eight-year follow-up data from the ENZAMET study, conducted by ANZUP and the University of Sydney, will be presented on June 2 at ASCO. That trial also showed survival benefits with XTANDI plus testosterone suppression over non-steroidal anti-androgens (NSAA) plus testosterone suppression. The median OS for the XTANDI group was 8 years, compared to 5.8 years in the NSAA group, with a 27% reduction in the risk of death and better progression-free survival outcomes (HR: 0.49).

“Data from the eight-year follow-up of XTANDI are highly encouraging, as they show the progression-free survival and overall survival benefits are sustained out to at least eight years. These results further support the value of XTANDI as a treatment regimen for metastatic hormone-sensitive prostate cancer,” said Christopher Sweeney, MBBS, DHS, FRACP, ANZUP Cancer Trials Group Limited, Sydney, Australia, and ENZAMET follow-up primary investigator. 

“The survival benefits of intervention with XTANDI in advanced prostate cancer are well-recognized. The collective – and growing – body of data for XTANDI continues to reinforce its long-term efficacy and patient impact in prostate cancer, including in the metastatic setting, and shows that XTANDI is changing the trajectory of those living with the disease,” added Shontelle Dodson, Executive Vice President, Head of Medical Affairs, Astellas. 

These long-term findings solidify XTANDI’s role as a key treatment for mHSPC, with no new safety concerns reported. Currently approved in over 90 countries and used by over one million patients globally.

“Until recently, patients with metastatic hormone-sensitive prostate cancer faced a poor prognosis, particularly in advanced stages, often due to treatment resistance. As the only androgen receptor inhibitor demonstrating sustained five-year survival in this patient population, these data further reinforce XTANDI combined with androgen deprivation therapy as the standard-of-care for treating this advanced disease,” said Johanna Bendell, M.D., Oncology Chief Development Officer, Pfizer.