The U.S. Food and Drug Administration on Wednesday approved Johnson & Johnson's Erleada treatment for use in prostate cancer patients whose cancer has not spread but continues to grow despite hormone therapy.

The drug is the first FDA-approved treatment for non-metastatic, castration-resistant prostate cancer, the regulator said. 

The approval was based on a trial goal that measured the length of time tumors did not spread to other parts of the body, or death occurred after starting the treatment, the FDA said.

According to the National Cancer Institute, about 161,360 men were diagnosed with prostate cancer in 2017, and 26,730 were expected to die of the disease.

The drug is expected to compete with Pfizer's Xtandi, which has shown impressive trial data in the treatment of prostate cancer.

Earlier this month, data from a study testing Xtandi showed that use of the drug in early stage prostate cancer on top of standard hormone therapy reduced the risk of the disease spreading or death by 71 percent compared with hormone therapy alone.