Pfizer and Astellas have announced that the US Food and Drug Administration (FDA) has approved a supplemental New Drug Application (sNDA) for the companies’ joint drug Xtandi (enzalutamide).

The treatment has been approved for patients with metastatic castration-sensitive prostate cancer, marking it as the first and only oral treatment approved by the FDA in three distinct types of advanced prostate cancer – non-metastatic and metastatic castration-resistant prostate cancer (CRPC) and mCSPC.

The companies say that the approval is based on results from ARCHES, a randomised Phase III study which evaluated 1,150 men with mCSPC and met its primary endpoint of radiographic progression-free survival (rPFS), reducing the risk of radiographic progression or death by 61%.

Further to the endpoint, the safety analysis of the ARCHES trial was generally consistent with the safety profile of Xtandi in previous clinical trials in CRPC.

The approval “adds to over a decade of global clinical research aimed at better understanding the potential benefit of Xtandi for men with advanced prostate cancer,” said Andy Schmeltz, global president, Pfizer Oncology.

He continued, ”The FDA approval marks continued progress to help meet the needs of patients, including men living with metastatic castration-sensitive prostate cancer.”

In 2019, it is estimated that just over 40,000 men in the United States are living with mCSPC. Men are considered castration (or hormone) sensitive if their disease still responds to medical or surgical treatment to lower testosterone levels.