• Enzalutamide is the first androgen receptor-inhibitor to demonstrate a statistically significant improvement in metastasis-free survival (MFS) in this patient population in a randomized, controlled clinical trial

NEW YORK, NY, USA & TOKYO, Japan I September 14, 2017 I Pfizer Inc. (NYSE:PFE) and Astellas Pharma Inc. (TSE: 4503, President and CEO: Yoshihiko Hatanaka, “Astellas”) announced today that the Phase 3 PROSPER trial evaluating XTANDI® (enzalutamide) plus androgen deprivation therapy (ADT) versus ADT alone in patients with non-metastatic (M0) Castration-Resistant Prostate Cancer (CRPC) met its primary endpoint of improved metastasis-free survival (MFS). The preliminary safety analysis of the PROSPER trial appears consistent with the safety profile of XTANDI in previous clinical trials.

“Many prostate cancer patients who initiate androgen deprivation therapy will experience disease progression illustrated by a rising PSA level, and currently, there are no FDA-approved treatment options for patients with non-metastatic CRPC until they develop confirmed radiographic metastatic disease,” said Neal Shore, M.D., director, CPI, Carolina Urologic Research Center.

Based on the results of PROSPER, the companies intend to discuss the data with global health authorities to potentially support expanding the label for XTANDI to cover all patients with CRPC.

“We are delighted with the significant results seen in the PROSPER study, showing that XTANDI plus ADT delayed clinically detectable metastases compared to ADT alone in patients with non-metastatic CRPC whose only sign of underlying disease was a rapidly rising prostate-specific antigen (PSA) level. We look forward to discussing the data with regulatory authorities,” said Mace Rothenberg, M.D., chief development officer, Oncology, Pfizer Global Product Development. “XTANDI is already established as a standard of care for men with metastatic CRPC based on the results of prior studies, such as AFFIRM and PREVAIL, which demonstrated that XTANDI delayed disease progression and improved overall survival in men with clinically detectable metastatic disease.”

“We want to thank the patients, family members and clinicians who participated in the PROSPER trial and helped advance the scientific understanding of the potential role for XTANDI in this prevalent disease,” said Steven Benner, M.D., senior vice president and global therapeutic area head, oncology development, Astellas. “We look forward to further analyzing the detailed efficacy and safety results from PROSPER, and submitting them for presentation at an upcoming major medical meeting.”

As part of Pfizer and Astellas’ ongoing commitment to the clinical development of enzalutamide in areas of greatest unmet need, the companies initiated the PROSPER trial to evaluate the potential benefits of XTANDI in men with non-metastatic CRPC, an earlier stage of prostate cancer where there are currently no FDA-approved treatment options. On June 9, 2017, the companies announced an amendment to the PROSPER protocol, which accelerated the clinical trial completion date by two years.

XTANDI is currently approved for the treatment of metastatic CRPC based on clinical data from previous studies that showed a statistically significant overall survival benefit for XTANDI versus placebo in the metastatic CRPC setting. XTANDI has been prescribed to more than 185,000 patients globally since its first approval in 2012.

About PROSPER

The Phase 3 randomized, double-blind, placebo-controlled, multi-national trial enrolled approximately 1,400 patients with non-metastatic castration-resistant prostate cancer (CRPC) at sites in the United States, Canada, Europe, South America and the Asia Pacific region. PROSPER enrolled patients with prostate cancer that had progressed, based on a rising prostate-specific antigen (PSA) level despite androgen deprivation therapy (ADT), but who had no symptoms with no prior or present evidence of metastatic disease. The primary objective of the trial was metastasis-free survival (MFS). MFS is a measure of the amount of time that passes until a cancer can be radiographically detected as having metastasized, or spread, to other parts of the body. The trial evaluated enzalutamide at a dose of 160 mg taken orally once daily plus ADT, versus placebo plus ADT. For more information on the PROSPER trial go to www.clinicaltrials.gov.

XTANDI has not yet been evaluated by the FDA for the treatment of patients with non-metastatic CRPC.

About Non-Metastatic Castration-Resistant Prostate Cancer

According to the American Cancer Society, more than 161,000 men are estimated to be diagnosed with prostate cancer in 2017.[i] Castration-resistant prostate cancer (CRPC) refers to the subset of men whose prostate cancer progresses despite androgen deprivation therapy.[ii] Non-metastatic CRPC means there is no clinically detectable evidence of the cancer spreading to other parts of the body (metastases), and there is a rising prostate-specific antigen (PSA) level.[iii] Many men with non-metastatic CRPC will go on to develop metastatic CRPC.[iv]

About XTANDI® (enzalutamide) capsules

XTANDI (enzalutamide) is an androgen receptor inhibitor that blocks multiple steps in the androgen receptor signaling pathway within the tumor cell. In preclinical studies, enzalutamide has been shown to competitively inhibit androgen binding to androgen receptors, and inhibit androgen receptor nuclear translocation and interaction with DNA. The clinical significance of this mechanism of action (MOA) is unknown.

XTANDI is approved by the U.S. Food and Drug Administration for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). Additional ongoing studies, such as the ARCHES trial in metastatic hormone-sensitive prostate cancer and the EMBARK trial in non-metastatic hormone-sensitive prostate cancer, are continuing to evaluate the potential of enzalutamide to help patients in need.

About Astellas

Astellas Pharma Inc., based in Tokyo, Japan, is a company dedicated to improving the health of people around the world through the provision of innovative and reliable pharmaceutical products. We focus on Urology, Oncology, Immunology, Nephrology and Neuroscience as prioritized therapeutic areas while advancing new therapeutic areas and discovery research leveraging new technologies/modalities. We are also creating new value by combining internal capabilities and external expertise in the medical/healthcare business. Astellas is on the forefront of healthcare change to turn innovative science into value for patients. For more information, please visit our website at www.astellas.com/en.

About Pfizer Oncology

Pfizer Oncology is committed to pursuing innovative treatments that have a meaningful impact on those living with cancer. As a leader in oncology speeding cures and accessible breakthrough medicines to patients, Pfizer Oncology is helping to redefine life with cancer. Our strong pipeline of biologics, small molecules and immunotherapies, one of the most robust in the industry, is studied with precise focus on identifying and translating the best scientific breakthroughs into clinical application for patients across a wide range of cancers. By working collaboratively with academic institutions, individual researchers, cooperative research groups, governments and licensing partners, Pfizer Oncology strives to cure or control cancer with its breakthrough medicines. Because Pfizer Oncology knows that success in oncology is not measured solely by the medicines you manufacture, but rather by the meaningful partnerships you make to have a more positive impact on people’s lives. Learn more about how Pfizer Oncology is applying innovative approaches to improve the outlook for people living with cancer at http://www.pfizer.com/research/therapeutic_areas/oncology.

About the Pfizer/Astellas Collaboration

In October 2009, Medivation, Inc., which is now part of Pfizer (NYSE:PFE), and Astellas (TSE: 4503) entered into a global agreement to jointly develop and commercialize enzalutamide. The companies are collaborating on a comprehensive development program that includes studies to develop enzalutamide across the full spectrum of advanced prostate cancer as well as other cancers. The companies jointly commercialize XTANDI in the United States and Astellas has responsibility for manufacturing and all additional regulatory filings globally, as well as commercializing XTANDI outside the United States.

SOURCE: Pfizer