Astellas' Xtandi to challenge J&J's Zytiga in the EU with pre-chemo OK

After ringing up a key U.S. approval in September to threaten Johnson & Johnson's ($JNJ) Zytiga, Astellas' Xtandi now has what it needs to ramp up its market-share battle in the EU, too.

EU regulators have cleared the oral prostate cancer med to treat patients with metastatic castration-resistant cancer in a pre-chemo setting, the Japanese pharma announced early this week. They based the nod on results from the Phase III PREVAIL study, which showed Xtandi reduced the risk of radiographic progression or death by 81% compared with placebo.

It's an indication key competitor Zytiga has boasted since last January, and Astellas will get to work immediately trying to top the market share J&J has built up over the past two years. The company said it would launch Xtandi in pre-chemo patients in the first European countries, including the U.K., later this month.

Astellas and its partner, Medivation ($MDVN), have already gotten to work challenging J&J in the U.S., where Xtandi won the pre-chemo OK nearly three months back. The FDA approval marked the first opportunity for Xtandi to cut into Zytiga's market share since the next-gen J&J pill hit the ground running in April 2011.

Ultimately, though, analysts expect Xtandi to eventually overtake Zytiga despite the latter's head start. For one, it has convenience on its side: It's used on its own, while patients take its rival alongside prednisone. And as Leerink Partners analyst Howard Liang wrote in a September note to clients, the strong uptake Xtandi has already seen in post-chemo patients bodes well as it enters the head-to-head battle.

"Strong adoption of Xtandi among oncologists as the preferred agent in the post-chemo setting, in our opinion, speaks to the preference for Xtandi's advantage that goes beyond lack of steroid co-administration and sets up potentially an even stronger launch following pre-chemo approval," he wrote.

- read Astellas' release

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