What is this summary about?ENZAMET is a large international clinical trial involving people with metastatic hormone sensitive prostate cancer (mHSPC). Prior to the trial, standard treatment included testosterone suppression and sometimes, chemotherapy. However, the researchers thought enzalutamide, an anti-androgen (hormone) medicine, which helps to block the effects of testosterone, might be helpful if added to testosterone suppression.What are the key takeaways?ENZAMET showed that the addition of enzalutamide to standard testosterone suppression treatment for mHSPC improved survival, resulting in an increase in the percent of participants alive at 5 years from 57% to 67%. Enzalutamide extended the time until the cancer grew. Side effects were in keeping with what was already known about enzalutamide and these risks were outweighed by improved cancer control in the long-term.What are the main conclusions reported by the researchers?The combination of testosterone suppression plus enzalutamide is a very effective first-line treatment for mHSPC.[Box: see text].