Pfizer, Astellas Pharma' Xtandi combo therapy cuts risk of metastasis, death by 58 percent in prostate cancer

“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 release stated.

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.

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