FDA Grants Priority Review to Xtandi for Earlier Treatment in Prostate Cancer

The FDA has accepted and granted priority review for the supplemental new drug application (sNDA) for Xtandi (enzalutamide) to treat patients with non-metastatic castration-sensitive prostate cancer with an increasing prostate-specific antigen (PSA) level, which is referred to biochemical recurrence (BCR). The Prescription Drug User Fee Act (PDUFA) date for an anticipated FDA decision is in fourth quarter of 2023.

“Biochemical recurrence can be one of the first indicators that prostate cancer is returning or will spread, particularly among those patients that experience rapid PSA doubling times,” Ahsan Arozullah, M.D., MPH, senior vice president and head of oncology development, Astellas, said in a press release. “The goal of treatment in this setting is to delay the spread of the cancer cells to other parts of the body.”

Of men who have undergone prostate cancer treatment, including radical prostatectomy, radiotherapy, or both, an estimated 20% to 40% will experience a biochemical recurrence within 10 years. About nine in 10 men with high risk biochemical recurrence will develop metastatic prostate cancer.

Developed by Astella and Pfizer, Xtandi is an androgen receptor signaling inhibitor. It is already available to treat patients with castration-resistant prostate cancer and metastatic castration-sensitive prostate cancer. The list price of Xtandi 40 mg is $14,383 for a supply of 120 capsules, according to Drugs.com. The companies offer copay support, as well as a patient assistance program for those who are uninsured.

The submission is based on results from the phase 3 EMBARK trial, which evaluated patients in three treatment arms: Xtandi plus leuprolide, placebo plus leuprolide, or XtandiX monotherapy. The study met its primary endpoint of metastasis-free survival (MFS) for the Xtandi plus leuprolide arm, demonstrating a 58% reduction in the risk of metastasis or death over placebo plus leuprolide.

The most common adverse events with the combination therapy were fatigue, hot flush, and arthralgia and in those treated with Xtandi monotherapy were fatigue, gynecomastia, and arthralgia. Detailed results from the trial were presented as a plenary session during the 2023 American Urological Association Annual Meeting on April 29.

In June, the FDA approved the combination of Xtandi and Pfizer’s Talzenna talazoparib), an oral poly ADP-ribose polymerase (PARP) inhibitor, for adult patients with homologous recombination repair (HRR) gene-mutated metastatic castration resistant prostate cancer