FDA accepts sNDA for Xtandi to expand its indication to include men with non-metastatic castration-resistant prostate cancer. - Pfizer + Astellas Pharma.

Pfizer Inc. and Astellas Pharma Inc. announced that a supplemental New Drug Application (sNDA) for Xtandi (enzalutamide) has been accepted for filing and granted Priority Review designation by the FDA. If approved, the sNDA would expand the indication of Xtandi to include men with non-metastatic Castration-Resistant Prostate Cancer (CRPC), based on data from the Phase III PROSPER trial.

Xtandi is currently indicated for the treatment of patients with metastatic CRPC. The FDA grants Priority Review designation to applications for drugs that, if approved, may offer significant improvements in the safety and effectiveness of the treatment of serious conditions when compared to standard applications. Under Priority Review, the FDA aims to take action on an application within six months of receipt, as compared to ten months under standard review. The Prescription Drug User Fee Act (PDUFA) goal date assigned by the FDA is July 2018. In addition, the European Medicines Agency (EMA) has validated the Type II Variation submitted for Xtandi seeking to expand the current indication to the same patient population and started the review process on 5 March 2018 .

The PROSPER trial evaluated Xtandi plus androgen deprivation therapy (ADT) versus ADT alone in 1,401 patients with non-metastatic CRPC. The study met its primary endpoint, demonstrating that the use of Xtandi plus ADT significantly reduced the risk of developing metastasis or death compared to ADT alone. Adverse events in the PROSPER trial were higher in the enzalutamide plus ADT arm compared to ADT alone (87% vs. 77%), and were generally consistent with those reported in prior enzalutamide clinical trials in patients with metastatic CRPC. Results from the PROSPER trial were presented at the 2018 Genitourinary Cancers Symposium (ASCO GU) in February.