UPDATED: Medivation shares skyrocket on positive PhIII prostate cancer data

Medivation is reporting a promising set of late-stage data for MDV3100 this morning, offering some hard proof that the drug compares favorably with the newly-approved Zytiga for improving overall survival of advanced prostate cancer victims without some of Zytiga's safety issues. The news, which sets the biotech squarely on the path to the FDA, caused the biotech's shares ($MDVN) to soar 124%.

Investigators recorded a median 4.8 month survival advantage for MDV3100 compared to placebo in the Phase III AFFIRM trial, a definite edge over the 3.9 month median that Zytiga required to win an approval. That was also good enough for the independent monitoring board to recommend that the trial be stopped so that all the men in the study could be given Medivation's drug, which blocks the androgen receptor to prevent cancer cells from reacting to testosterone.

Analysts have consistently seen this as something of a clinical horse race that Medivation couldn't afford to lose. By posting solid overall survival gains in the study, the biotech appears on a path to approval for a treatment that doesn't require prednisone--like Zytiga--steering clear of a corticosteroid that is linked to high blood pressure. The biotech, which is partnered with Astellas, said in a statement today that it plans to sit down with the FDA in a pre-NDA meeting early next year.

"MDV3100 does look better than Zytiga from an efficacy perspective," noted JPMorgan analyst Meacham this morning.

The data represents a big victory for Medivation CEO David Hung, who's been operating under a cloud since the back-to-back Phase III failures of Dimebon, its once high-flying Alzheimer's treatment which so far hasn't managed to beat a placebo in pivotal studies. MDV3100 was a must-win program, and investors would have been unforgiving of any fresh failure in the clinic.  

In an interview with FierceBiotech, Hung noted that Medivation is conducting a broad range of late-stage clinical studies for MDV3100 as it looks to broaden the use of the drug following a prospective approval for advanced cases. "We're really excited by these results," he says, noting that Medivation stands to earn $655 million in milestones from Astellas, with $335 million on the table prior to launch. Hung added that the company will discuss the current milestones involved in an upcoming conference call. 

The potential approval of MDV3100 also sets up a potential combo treatment with Zytiga, hitting twin mechanisms for the disease. And it's also another problem for Dendreon ($DNDN), which has been experiencing major problems marketing Provenge for prostate cancer. Hung also noted that the biotech has a preclinical study for MDV3100 in breast cancer underway.

- here's the press release
- here's the Reuters story