The FDA approved Erleada (apalutamide) for the treatment of patients with prostate cancer that has not spread but continues to grow despite hormone therapy, marking the first FDA approved treatment for non-metastatic, castration-resistant prostate cancer.

The approval is the first to use the endpoint of metastasis-free survival, measuring the length of time that tumors did not spread to other parts of the body or that death occurred after starting treatment.

Erleada, an androgen receptor inhibitor, works by blocking androgens on the tumor that can promote growth, such as testosterone. Its common side effects include fatigue, nausea, weight loss and decreased appetite, while severe side effects include falls, fractures and seizures.

The FDA based its approval on a randomized clinical trial involving 1,207 patients with non-metastatic, castration resistant prostate cancer who received either Erleada or a placebo. All participants in the trial also received hormone therapy.