XTANDI® (enzalutamide) plus Leuprolide Reduced the Risk of Metastasis by 58% in Non-Metastatic Hormone-Sensitive Prostate Cancer versus Placebo plus Leuprolide
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- Published on Monday, 01 May 2023 08:49
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Data from Phase 3 EMBARK trial to be presented as a plenary session during the 2023 American Urological Association Annual Meeting
Results show the potential for XTANDI to add to the standard of care in prostate cancer, if approved
TOKYO, Japan and NEW YORK, NY, USA I April 29, 2023 I Astellas Pharma Inc. (TSE: 4503, President and CEO: Naoki Okamura, "Astellas") and Pfizer Inc. (NYSE: PFE) announced today that XTANDI® (enzalutamide) plus leuprolide significantly reduced the risk of metastasis or death by 58% versus placebo plus leuprolide (Hazard Ratio [HR]: 0.42; 95% Confidence Interval [CI], 0.30–0.61; P<0.0001), as assessed by the primary endpoint of metastasis-free survival (MFS), in men with non-metastatic hormone-sensitive prostate cancer (nmHSPC; also known as non-metastatic castration-sensitive prostate cancer or nmCSPC) with high-risk biochemical recurrence (BCR). These data from the Phase 3 EMBARK trial, which evaluated patients across three study arms (XTANDI plus leuprolide [n=355], placebo plus leuprolide [n=358], or XTANDI monotherapy [n=355]), were presented as a plenary session during the 2023 American Urological Association Annual Meeting (Saturday, April 29 at 9:45 a.m. CT).
The overall safety profile was consistent with the known safety profile of each of the medicines. The most common adverse events in those treated with XTANDI plus leuprolide were fatigue, hot flush, and arthralgia and in those treated with XTANDI monotherapy were fatigue, gynecomastia, and arthralgia.
"There are patients with localized prostate cancer who undergo prostatectomy or radiation therapy in an attempt to cure their disease, but, unfortunately, some patients will develop BCR," said Neal Shore, M.D., F.A.C.S., U.S. Chief Medical Officer of Urology and Surgical Oncology, GenesisCare, Director, Carolina Urologic Research Center, and Primary Investigator for the EMBARK study. "Importantly, some patients with BCR are at very high risk for developing metastatic disease, which can lead to a cascade of therapeutic interventions. The clinical goal of BCR therapy is to delay cancer progression and avoid metastatic disease. The MFS results from the EMBARK study demonstrate that this intervention with XTANDI plus leuprolide was statistically significant for patients with high-risk BCR."
"The EMBARK study is a Phase 3 trial exploring the potential of enzalutamide in patients with non-metastatic hormone-sensitive prostate cancer with high-risk BCR," said Stephen J. Freedland, M.D., Director of the Center for Integrated Research in Cancer and Lifestyle and the Warschaw Robertson Law Families Chair in Prostate Cancer at Cedars-Sinai Cancer and Co-Principal Investigator of the Clinical Trial. "If approved, we hope to bring a new option to men earlier in the course of their disease."
Consistent with the study's primary endpoint, statistically significant and clinically meaningful improvements were also observed in the trial's key secondary endpoints in both the XTANDI combination and monotherapy arms. Specifically, the XTANDI monotherapy arm demonstrated that treatment with XTANDI reduced the risk of metastasis or death by 37% versus leuprolide plus placebo (HR: 0.63; 95% CI, 0.46–0.87; P=0.0049), meeting its MFS endpoint. Treatment with XTANDI plus leuprolide and XTANDI monotherapy reduced the risk of PSA progression by 93% (HR: 0.07; 95% CI, 0.03–0.14; P<0.0001) and 67% (HR: 0.33; 95% CI, 0.23–0.49; P<0.0001), respectively, versus placebo plus leuprolide. The progression risk in starting a new antineoplastic therapy was reduced by 64% in those treated with XTANDI plus leuprolide (HR: 0.36; 95% CI, 0.26–0.49; P<0.0001) and 46% in those treated with XTANDI monotherapy (HR: 0.54; 95% CI, 0.41–0.71; P<0.0001) versus placebo plus leuprolide.
A positive trend in the key secondary endpoint of overall survival (OS) was also observed in the XTANDI combination arm at the time of the analysis, but these data were not yet mature. Patients in the trial will be followed for a subsequent final OS analysis.
Detailed results from the trial will be submitted for peer-reviewed publication. Additionally, the EMBARK data will be discussed with regulatory authorities, including the U.S. Food and Drug Administration (FDA), to support a potential regulatory submission for XTANDI in this indication in 2023.
The Astellas- and Pfizer-led Phase 3, randomized, double-blind, placebo-controlled, multi-national trial enrolled 1,068 patients with non-metastatic hormone-sensitive prostate cancer (nmHSPC; also known as non-metastatic castration-sensitive prostate cancer or nmCSPC) with high-risk biochemical recurrence (BCR) at sites in the United States, Canada, Europe, South America and the Asia-Pacific region. Patients who were considered to experience high-risk BCR had a prostate-specific antigen doubling time (PSA-DT) ≤ 9 months; serum testosterone ≥ 150 ng/dL (5.2 nmol/L); and screening PSA by the central laboratory ≥ 1 ng/mL if they had a radical prostatectomy (with or without radiotherapy) as primary treatment for prostate cancer, or at least 2 ng/mL above the nadir if they had radiotherapy only as primary treatment for prostate cancer. Patients in the EMBARK trial were randomized to receive enzalutamide 160 mg daily plus leuprolide (n=355), enzalutamide 160 mg as a monotherapy (n=355), or placebo plus leuprolide (n=358). Leuprolide 22.5 mg was administered every 12 weeks.
The primary endpoint of the trial was metastasis-free survival (MFS) for enzalutamide plus leuprolide versus placebo plus leuprolide. MFS is defined as the duration of time in months between randomization and the earliest objective evidence of radiographic progression by central imaging or death. For more information on the EMBARK trial (NCT02319837) go to www.clinicaltrials.gov.
XTANDI, either in combination with leuprolide or as a monotherapy, has not been approved by any regulatory agency for the treatment of patients with nmHSPC with high-risk BCR.
About Non-Metastatic Hormone-Sensitive Prostate Cancer with High-Risk Biochemical Recurrence
In non-metastatic hormone- (or castration-) sensitive prostate cancer (nmHSPC or nmCSPC), no evidence of the cancer spreading to distant parts of the body (metastases) is detectable with conventional radiological methods (CT/MRI), and the cancer still responds to medical or surgical treatment designed to lower testosterone levels.1,2 Of men who have undergone definitive prostate cancer treatment, including radical prostatectomy, radiotherapy, or both, an estimated 20-40% will experience a biochemical recurrence (BCR) within 10 years.3 About 9 out of 10 men with high-risk BCR will develop metastatic disease, and 1 in 3 will die as a result of the recurrence.4 The EMBARK trial focused on men with high-risk BCR. Per the EMBARK protocol, patients with nmHSPC and high-risk BCR are those initially treated by radical prostatectomy or radiotherapy, or both, with a prostate-specific antigen doubling time (PSA-DT) ≤ 9 months. High-risk BCR patients with a PSA-DT of ≤ 9 months have a higher risk of metastases and death.5
About XTANDI® (enzalutamide)
XTANDI (enzalutamide) is an androgen receptor signaling inhibitor. XTANDI has received regulatory approvals in one or more countries around the world for use in men with metastatic hormone-sensitive prostate cancer (mHSPC), metastatic castration-resistant prostate cancer (mCRPC), and non-metastatic castration-resistant prostate cancer (nmCRPC). XTANDI is currently approved for one or more of these indications in more than 100 countries, including in the United States, European Union and Japan. One million patients have been treated with XTANDI globally.6
Please see Full Prescribing Information for additional safety information.
Astellas Pharma Inc. is a pharmaceutical company conducting business in more than 70 countries around the world. We are promoting the Focus Area Approach that is designed to identify opportunities for the continuous creation of new drugs to address diseases with high unmet medical needs by focusing on Biology and Modality. Furthermore, we are also looking beyond our foundational Rx focus to create Rx+® healthcare solutions that combine our expertise and knowledge with cutting-edge technology in different fields of external partners. Through these efforts, Astellas stands on the forefront of healthcare change to turn innovative science into VALUE for patients. For more information, please visit our website at https://www.astellas.com/en.
About Pfizer Oncology
At Pfizer Oncology, we are committed to advancing medicines wherever we believe we can make a meaningful difference in the lives of people living with cancer. Today, we have an industry-leading portfolio of 24 approved innovative cancer medicines and biosimilars across more than 30 indications, including breast, genitourinary, colorectal, blood and lung cancers, as well as melanoma.
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 commercial agreement to jointly develop and commercialize XTANDI® (enzalutamide) in the United States, while Astellas has responsibility for manufacturing and all additional regulatory filings globally, as well as commercializing the product outside the United States. Pfizer receives alliance revenues as a share of U.S. profits and receives royalties on sales outside the U.S.
1 Cancer.net. Prostate Cancer: Types of Treatment (12-2022). https://www.cancer.net/cancer-types/prostate-cancer/types-treatment. Accessed March 16, 2023.
2 American Society of Clinical Oncology. ASCO Answers: Prostate Cancer (2021). http://www.cancer.net/sites/cancer.net/files/asco_answers_guide_prostate.pdf. Accessed March 16, 2023.
3 Ward JF, Moul JW. Rising prostate-specific antigen after primary prostate cancer therapy. Nat Clin Pract Urol. 2005 Apr;2(4):174-82. doi: 10.1038/ncpuro0145. PMID: 16474760.
4 Antonarakis, Emmanuel S et al. "The natural history of metastatic progression in men with prostate-specific antigen recurrence after radical prostatectomy: long-term follow-up." BJU international vol. 109,1 (2012): 32-9. doi:10.1111/j.1464-410X.2011.10422.
5 Paller, Channing J et al. "Management of patients with biochemical recurrence after local therapy for prostate cancer." Hematology/oncology clinics of North America vol. 27,6 (2013): 1205-19, viii. doi:10.1016/j.hoc.2013.08.005
6 Data on file. Northbrook, IL: Astellas Inc.
SOURCE: Astellas Pharma