Astellas and Pfizer Win New Prostate Cancer Indication From the FDA for Xtandi
Four months after filing a supplemental New Drug Application with the U.S. Food and Drug Administration (FDA), Astellas and Pfizer snagged regulatory approval for Xtandi as a treatment for non-metastatic Castration-Resistant Prostate Cancer (CRPC).
The two companies filed the application in March, one month after they impressive Phase III data that showed the efficacy of Xtandi (enzalutamide) for that indication. The Phase III trial showed that a combination of Xtandi plus ADT significantly reduced the risk of developing metastases or death by 71 percent. Additionally, the Phase III trial data showed the combination treatment had a 93 percent reduction in relative risk of prostate-specific antigen (PSA) progression, a biomarker tied to the worsening of a disease, compared to patients who received ADT alone. The companies said the median time for the primary endpoint of metastasis-free survival (MFS), was 36.6 months for men who received Xtandi in comparison to 14.7 months for those who only had the ADT treatment.
Prostate cancer is the second most common cancer in men worldwide, with about 164,000 expected diagnoses in the United States this year. Castration-resistant prostate cancer refers to the subset of men whose prostate cancer progresses despite castration levels of testosterone. Xtandi was approved in 2012 for late-stage prostate cancer.
Andy Schmeltz, Pfizer’s head of oncology, said that reducing the risk of disease progression is an important treatment goal in castration-resistant prostate cancer. The disease becomes more difficult to treat in advanced stages
“With Xtandi, men with CRPC now have a clinically proven treatment option that reduces the risk of metastasis. This approval delivers on the potential for Xtandi to help men at an earlier stage of the disease, and we are continuing to evaluate the medicine in an extensive development program across additional prostate cancer populations,” Schmeltz said.
Steven Benner, head of oncology at Astellas, noted that Xtandi has become a standard of care in the treatment of men with metastatic CRPC. The latest approval “builds on the body of evidence for Xtandi,” Benner said.
The regulatory approval was expedited due to the use of an FDA Priority Review Designation that was provided based on the Phase III results. The most recent approval of Xtandi makes it the first and only oral medication FDA-approved for both non-metastatic and metastatic CRPC, the two companies said.
The newest approval for Xtandi broadens the indication for the medication. The drug was initially approved for the treatment of patients with metastatic CRPC.
"With today's approval, there is now a new option for men with non-metastatic CRPC, who are in between the failure of androgen deprivation therapy resulting in CRPC and the onset of metastatic disease," Jonathan Simons, head of the Prostate Cancer Foundation said. "As a foundation that drives research aimed at improving patient outcomes, it is exciting to see approvals like this, which are vital to help address unmet patient needs."