Positive Late-Stage Data Reported for Enzalutamide (Xtandi) in Men With Metastatic Prostate Cancer
Treatment provides significant survival benefits (January 28)
Positive results have been reported from a phase III trial of enzalutamide (Xtandi, Medivation Inc./Astellas Pharma) in patients with chemotherapy-naïve metastatic prostate cancer who had failed androgen-deprivation therapy and had few or no symptoms.
The new data will be presented January 30 at the American Society of Clinical Oncology (ASCO) 2014 Genitourinary Cancers Symposium in San Francisco.
Enzalutamide significantly reduced the risk of death by 29% (hazard ratio [HR], 0.71; P < 0.0001) compared with placebo. This benefit was observed despite substantial use of subsequent therapies (40% of the enzalutamide group and 70% of the placebo group).
Treatment with enzalutamide also significantly reduced the risk of radiographic progression or death by 81% compared with placebo (HR, 0.19; P < 0.0001).
Moreover, men taking enzalutamide experienced a 17-month delay in the time to initiation of chemotherapy compared with men taking placebo (28.0 months versus 10.8 months, respectively; HR, 0.35; P < 0.0001).
Common side effects occurring more often in the enzalutamide-treated men included fatigue, back pain, constipation, and arthralgia.
Enzalutamide is an androgen receptor inhibitor that acts on the androgen receptor signaling pathway. The drug has been shown to competitively inhibit androgen binding to androgen receptors, and to inhibit androgen receptor nuclear translocation and interaction with DNA.
Xtandi (enzalutamide) was approved by the FDA in August 2012 and is indicated for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) who have received docetaxel.
Source: Medivation, Inc.; January 28, 2014.