The US FDA has approved the use of the oncology drug Xtandi prior to chemotherapy in patients with advanced prostate cancer.
Xtandi (enzalutamide), an oral once-daily drug developed by Astellas and its partner Medivation, is now available in the US to treat men with metastatic castration-resistant prostate cancer (CRPC) who have not received previous treatment.
This expands its existing indication, which restricted the drug’s use to men who had previously been treated with a form of chemotherapy known as docetaxel.
The approval comes after a priority review for Xtandi in this pre-chemotherapy indication. The FDA reserves this process for drugs that have shown evidence of effectiveness in serious conditions, and aims to shorten the assessment period for the treatment.
During this review the FDA assessed data from the phase III trials PREVAIL and AFFIRM. These demonstrated that Xtandi was able to reduce the risk of death by 29% compared with placebo in the target group.
Dr Tomasz Beer, co-principal investigator of the PREVAIL study added: “Furthermore, in the PREVAIL trial, the median time to initiating chemotherapy was delayed by 17 months with enzalutamide treatment as compared to placebo, so the result is a meaningful period of time during which men have their disease controlled without the need for chemotherapy.”
Astellas and Medivation will welcome the first-line indication for Xtandi as it competes with rival drugs, including Johnson & Johnson’s Zytiga (abiraterone), which was approved by the FDA in late 2012 to treat men with advanced prostate cancer prior to chemotherapy when used in combination with prednisone.
Zytiga has performed well in this indication, racking up US sales of $464m for the first six months of 2014 and $1bn in global revenues for the same period.
Xtandi has also achieved success in its post-chemotherapy indication, with revenues of $392m in the US for its first full year on the market.
The expanded indication should give these figures a substantial boost for Astellas, however, while the drug’s original creators Medivation will also benefit from $90m milestone payment.