Pfizer and Astellas Secure FDA Priority Review for Xtandi Combination Therapy in High-Risk Non-Metastatic Prostate Cancer

▎WuXi

Edited by Kant Content Team

Pfizer and Astellas Pharma announced today that the U.S. FDA has accepted and granted Priority Review to the supplemental New Drug Application (sNDA) for Xtandi (enzalutamide) to treat patients with non-metastatic castration-sensitive prostate cancer (nmCSPC) with high-risk biochemical recurrence (BCR). The FDA is set to complete its review in the fourth quarter of 2023.

In patients with nmCSPC, there is no evidence of cancer spreading to distant parts of the body (metastasis) detected by conventional radiological methods, and the cancer cells still respond to drugs or surgical treatments used to lower testosterone levels. However, among men receiving prostate cancer treatment (including radical prostatectomy, radiotherapy, or both), it is estimated that 20-40% of patients will experience BCR within 10 years.BCR is one of the first indicators of prostate cancer recurrence or potential spread.Approximately 9 out of 10 high-risk BCR men will develop metastatic disease, with one-third dying from recurrence.

Xtandi is an androgen receptor signaling inhibitor.Xtandi is a standard therapy that has received regulatory approval in many countries and regions worldwide for the treatment of male patients with metastatic castration-sensitive prostate cancer (mCSPC), metastatic castration-resistant prostate cancer (mCRPC), and non-metastatic castration-resistant prostate cancer (nmCRPC).

This sNDA submission is primarily based on the results of the Phase 3 EMBARK trial, which evaluated nmCSPC patients with high-risk BCR across three study groups: Xtandi plus leuprolide (n=355), placebo plus leuprolide (n=358), or Xtandi monotherapy (n=355).The study met its primary endpoint, with data showing that compared to patients in the placebo + leuprolide group, patients in the Xtandi + leuprolide group experienced a significant improvement in metastasis-free survival (MFS), with a statistically significant 58% reduction in the risk of metastasis or death (HR: 0.42; 95% CI: 0.30-0.61; p

The overall safety profile is consistent with the known safety profiles of each drug. The most common adverse events in the Xtandi plus leuprolide treatment group were fatigue, hot flashes, and arthralgia.