Medivation, Astellas ask FDA to approve Xtandi for pre-chemo prostate cancer use

Xtandi--FiercePharma file photo

The prostate cancer drug Xtandi has been a quick starter from, well, the start. The FDA approved it three months ahead of schedule in 2012 for men who have already had chemo. A study on pre-chemo cases was stopped almost a year early because the drug was so successful, and if the FDA approves it for that use, then the drug from Medivation ($MDVN) and Astellas Pharma will more quickly hit the aggressive financial goals that analysts have assigned it.

The drug companies on Wednesday said they are asking the FDA for approval for Xtandi (enzalutamide) to be used on patients with metastatic castration-resistant prostate cancer (mCRPC) who have not received chemotherapy. An approval for pre-chemo use would put Xtandi on more even footing with Johnson & Johnson's ($JNJ) Zytiga (abiterone), which was granted that use last year. Japan-based Astellas and San Francisco-based Medivation said they will go to the European Medicines Agency (EMA) later this year with an application for the pre-chemo indication.

Both Xtandi and Zytiga are pills that interfere with the testosterone that can feed the disease, although they operate in different ways. Zytiga was first to market but some analysts believe Xtandi will overtake it in sales, forecasting Xtandi will hit more than $2.7 billion in annual revenues in 2018. Estimates put Zytiga at $2.3 billion for that year. When the companies released data in January from the Phase III PREVAIL trial, Jefferies & Co. analyst Biren Amin told Bloomberg that he had bumped up his earnings forecast for Xtandi for this year by 34% to $866 million.

The study of more than 1,700 patients compared Xtandi to a placebo, finding that the drug reduced the risk of death by 29% and the risk of disease progression or death by 81%, compared with the imposter pill. The trial had been expected to continue until September of this year, but Xtandi proved so effective that it was stopped in October. Amin noted that Xtandi topped Zytiga "on every metric," including survival, PSA response and time to chemo. Those kinds of results have emboldened Medivation and Astellas to price Xtandi at a premium compared to the J&J drug: $7,450 per month for Xtandi, compared to $5,500 a month for Zytiga.

- here's the announcement
- read the PharmaTimes story

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