The US Food and Drug Administration (FDA) has approved Eli Lilly’s non-steroidal androgen receptor inhibitor (ARi), Nubeqa (darolutamide), for men with non-metastatic castration-resistant prostate cancer.

The drug has been approved under the governing body’s Priority Review designation, based on Phase III ARAMIS trial evaluating the efficacy and safety of darolutamide plus androgen deprivation therapy (ADT) compared to placebo plus ADT.

The trial demonstrated a highly significant improvement in the primary efficacy endpoint of metastasis-free survival (MFS), with a median of 40.4 months versus 18.4 months for placebo.

The compound, which is developed jointly by Bayer and Orion, has a distinct chemical structure that binds to the receptor with high affinity and exhibits strong antagonistic activity, thereby inhibiting the receptor function and the growth of prostate cancer cells.

“Patients at this stage of prostate cancer typically don’t have symptoms of the disease. The overarching goals of treatment in this setting are to delay the spread of prostate cancer and limit the burdensome side effects of therapy,” said Matthew Smith, director of the Genitourinary Malignancies Program, Massachusetts General Hospital Cancer Center. “This approval marks an important new option for the prostate cancer community.”

Prostate cancer that is treated with ADT but keeps progressing even when the amount of testosterone is reduced to very low levels in the body is known as castration-resistant prostate cancer.

Prostate cancer is the fifth leading cause of death from cancer in men. It results from the abnormal proliferation of cells within the prostate gland, which is part of a man’s reproductive system, mainly affects men over the age of 50, and the risk increases with age.