Astellas and Pfizer Announce Positive Top-Line Results from Phase 3 ARCHES Trial of XTANDI® (enzalutamide) in Men with Metastatic Hormone-Sensitive Prostate Cancer

San Francisco, CA USA (UroToday.com) -- Astellas Pharma Inc. President and CEO: Kenji Yasukawa, Ph.D., and Pfizer Inc. announced that the Phase 3 ARCHES trial evaluating XTANDI® (enzalutamide) plus androgen deprivation therapy (ADT) in men with metastatic hormone-sensitive prostate cancer (mHSPC) met its primary endpoint, significantly improving radiographic progression-free survival (rPFS) versus ADT alone. The preliminary safety analysis of the ARCHES trial appears consistent with the safety profile of XTANDI in previous clinical trials in castration-resistant prostate cancer (CRPC). Detailed results will be submitted for presentation at an upcoming medical congress.

“While XTANDI is currently approved for both metastatic and non-metastatic CRPC, there still remains a need for more treatment options for men with metastatic hormone-sensitive prostate cancer,” said Mace Rothenberg, M.D., Chief Development Officer, Oncology, Pfizer Global Product Development. “With these top-line results, we believe XTANDI has the potential to help men whose disease has progressed outside the prostate gland but still responds to treatment to lower testosterone.”
“The results from ARCHES demonstrate a statistically significant improvement in a key marker of disease progression – radiographic progression-free survival,” said Steven Benner, M.D., senior vice president and global therapeutic area head, Oncology Development, Astellas. “Based on the top-line results of ARCHES, we look forward to discussing the data with relevant health authorities to potentially support expanding the indication for XTANDI.”
XTANDI is currently approved in the U.S. and Japan for the treatment of CRPC and in the EU for the treatment of metastatic and high-risk non-metastatic CRPC. Since its initial approval in 2012, XTANDI has been prescribed to more than 330,000 men worldwide.1

About ARCHES: The Phase 3, randomized, double-blind, placebo-controlled, multi-national trial enrolled 1,150 patients with metastatic hormone-sensitive prostate cancer (mHSPC) at sites in the United States, Canada, Europe, South America and the Asia-Pacific region. Patients in the ARCHES trial were randomized to receive XTANDI 160 mg daily or placebo and continued on a luteinizing hormone-releasing hormone (LHRH) agonist or antagonist or had a history of bilateral orchiectomy. The ARCHES trial included patients with both low- and high- volume disease and both newly diagnosed patients with mHSPC and patients who had prior definitive therapy and subsequently developed metastatic disease. The trial also included some patients who had received recent treatment with docetaxel for mHSPC, but whose disease had not progressed. The primary endpoint of the trial was radiographic progression-free survival (rPFS), defined as the time from randomization to the first objective evidence of radiographic disease progression as assessed by central review, or death, whichever occurs first.

Reference:
1. Data on file. Northbrook, IL: Astellas Inc.