Xtandi will cost $7,450 a month
, Medivation said. That is higher than some analysts had expected.
Before 2004, the only drug shown to prolong the survival of men with advanced prostate cancer was the chemotherapy
drug docetaxel. Now there are four others on the market — Jevtana from Sanofi, Provenge from Dendreon, Zytiga from Johnson & Johnson and Xtandi, which is known generically as enzalutamide.
Xtandi is expected to compete most directly with Zytiga. Both are pills, while the other drugs are given intravenously. And both are aimed at the same patient population — men whose cancer has spread elsewhere in the body or recurred despite treatment aimed at suppressing production of the hormone testosterone
, which fuels prostate cancer growth.
Both drugs are approved for men who have already tried docetaxel, though both Medivation and Johnson & Johnson hope to eventually win approval for their drugs to be used before docetaxel, a potentially much larger market. Many patients would prefer to use the pills before having to try chemotherapy.Zytiga prolonged median survival by 3.9 months, as initially reported, though Johnson & Johnson later updated that figure to 4.6 months.
Zytiga, which was approved in April 2011, had worldwide sales of $432 million in the first six months of this year.
Xtandi and Zytiga have not been compared head-to-head in a clinical trial. But some analysts say Xtandi would have an edge because it does not have to be given with prednisone, a steroid
, to minimize side effects, as Zytiga does.
Xtandi has its own side effects, however, the most worrisome being seizures
, which were suffered by about 1 percent of men taking it in the clinical trial.