Astellas/Medivation seek EU expanded Xtandi mCRPC use
This article was originally published in Scrip
Astellas Pharma and partner Medivation have submitted a market authorization application in Europe for the expanded use of Xtandi (enzalutamide) in chemotherapy-naïve, metastatic castration-resistant prostate cancer (mCRPC) patients.
Xtandi is currently approved in Europe for the treatment of adult men with mCRPC whose disease has progressed on or after docetaxel chemotherapy.
Astellas and Medivation are already seeking approval for Xtandi in the chemo-naive mCRPC setting in the US. The companies submitted an application for expanded use of the drug to the US FDA in March this year (scripintelligence.com, 18 March 2014).
If approved for use in chemo-naïve patients Xtandi, an androgen receptor signaling inhibitor (ARSI), will be competing with Johnson and Johnson's Zytiga (abiraterone acetate) and Dendreon's Provenge (sipuleucel-T) as the only currently approved therapies for chemo-naïve mCRPC patients.
Datamonitor Healthcare analyst Colin White said that although Xtandi is playing catch up with J&J's Zytiga, it has still managed to achieve strong sales since its launch in 2012. Total global sales for Xtandi in 2012 were $71.5m, rising to $444.9m last year. Global sales of Zytiga, which first launch in Europe in 2011, were $961m in 2012, and reached $1,638m in 2013.
Meanwhile, Provenge sales have suffered as a result from increased competition from Xtandi and Zytiga. Dr White said he believes that Zytiga's expanded approval to the pre-chemotherapy setting in December 2012 is the primary cause of Provenge's declining sales. 2012 global sales of Provenge were $325.3m, falling to $283.7m last year.
According to the International Agency for Research on Cancer (IARC), prostate cancer is the most common cancer in men in Europe, accounting for over 20% of all cancer diagnoses (excluding non-melanoma skin cancer) and is the third most common cause of cancer death in Europe.
Astellas/Medivation's MAA submission is based on Phase III data from the PREVAIL trial, data for which was presented at American Society of Clinical Oncology's Genitourinary Cancers Symposium in San Francisco this year (scripintelligence.com, 29 January 2014).
Data from the Phase III trial showed that Xtandi displayed a significant benefit by extending lives and preventing the disease from worsening in patients who were not yet treated with chemotherapy. The study was stopped early in October 2013 because of high efficacy; both co-primary endpoints of improving overall survival (OS) and radiographic progression-free survival (rPFS) were met earlier than expected.