Enzalutamide (Xtandi) has a new, expanded FDA label. The new label conforms with the clinical trial (TERRAIN) results that Xtandi is a superior drug to Casodex (bicalutamide) for men with metastatic castration-resistant prostate cancer (CRPC).

The updated product label shows enzalutamide reduces the risk of radiographic progression or death by 40% vs. bicalutamide. Median radiographic progression-free survival was 19.5 months with enzalutamide compared with 13.4 months with bicalutamide.

Steven Benner, MD, senior vice president, therapeutic area head for oncology development, Astellas, said in a statement, “The addition of data from the TERRAIN trial continues to build the body of evidence that demonstrates the clinical impact Xtandi can have for patients living with metastatic CRPC”.

The safety profile of enzalutamide was consistent with previous reports. Many of the side effects of enzalutamide including fatigue, back pain, and hot flushes are more common and significant compared to Casodex.

To some extent, this label change is not particularly important for many of us. Casodex is normally used in men with prostate cancer that is still hormone responsive while Enzalutamide is a later stage drug.