J&J wows analysts with early success of Zytiga PhIII for prostate cancer

The news just keeps getting better for Johnson & Johnson's new prostate cancer drug Zytiga (abiraterone). Investigators unblinded a late-stage study of the drug--plus prednisone--for prostate cancer victims who had not been treated with chemotherapy. The blockbuster drug is already approved for treatment-resistant cases and the news heralds a quick-step expansion of the prospective patient population.

No data was delivered, but Johnson & Johnson ($JNJ) says the independent monitoring committee members for the study were satisfied that they had the results they were looking for on progression-free survival as well as the co-primary endpoint of overall survival along with key secondary endpoints. The move paves the way for J&J to start filing for expanded use later this year.

According to Adam Feuerstein at TheStreet, a J&J spokesperson confirmed that investigators had established a statistically significant response for PFS and a "strong trend" on OS, though the data in that category was not statistically significant. The independent data monitors "stopped the trial based on the totality of the data they saw," Kellie McLauglin told TheStreet, which included a statistically significant benefit for all secondary endpoints.

Dendreon ($DNDN), which will face additional pressure from an increasingly popular rival treatment to Provenge, saw its shares slide 13% on the news. Zytiga has been eating up market share as its reputation as a faster acting, more convenient therapy for prostate cancer--quick to ease pain and other effects of cancer--has spread among patients and physicians.

"The COU-AA-302 study has been a key priority for us as we expand our understanding of the utility of Zytiga in metastatic prostate cancer," said William N. Hait, the global chief of Janssen R&D. "We're delighted that these data will soon be added to the growing body of literature about this important medication."

The Phase III results also have implications for Medivation ($MDVN), which has a lot at stake with its late-stage program for MDV-3100. Medivation has been counting on a new approach that does away with the need for prednisone, which can trigger high blood pressure.

- here's the press release
- here's the report from TheStreet