Zytiga, Xtandi will help pump prostate cancer market to $9.1B

The market for prostate cancer drugs is expected to double by 2021 to $9.1 billion, thanks in part to the debut of new, more expensive drugs. According to Decision Resources, Johnson & Johnson's ($JNJ) Zytiga, along with Medivation ($MDVN) and Astellas Pharma's new Xtandi, will help drive sales growth in 7 major drug markets.

Zytiga has the lead, having been launched in the U.S. and Europe last year. Decision Resources says the J&J drug, marketed via its Janssen unit, has become the leading treatment for metastatic castrate-resistant prostate cancer that has stopped responding to chemo. The drug is expected to hit $1.8 billion in sales by 2015, the company says.

Meanwhile, Xtandi is coming on fast. The drug won approval from the FDA in August and was launched in September. It's priced at a premium--$7,450 wholesale for a 30-day supply, or about $85,000 annually--but Decision Resources expects it to overtake Zytiga, sales-wise. Zytiga runs about $5,500 per month, or $66,000 per year.

"[Xtandi] will become the top-selling agent in the prostate cancer market through 2021," Decision Resources analyst Rachel Webster says (as quoted by PharmaTimes). "We forecast Xtandi will garner sales of $2.2 billion by 2021."

- see the PharmaTimes story