Biotech Values

[pcrutch]

DNDN bounced after JNJ spokespeople said

"They reached statistical significance on a primary endpoint which was R-PFS and on all secondary endpoints and there was a strong trend for overall survival, all of which constituted compelling evidence of clinical benefit. And that led to the IDMC’s recommendation to unblind the trial. The survival data will continue to mature."

However, I think this point is moot, since one would expect the PFS endpoint would hit much earlier than OS in the pre-chemo population. DNDN's pivotal studies most definitely required completion to the final analysis for the OS to hit, since Provenge had no effect on PFS. I suspect strong trend would put the current OS p-value below 0.2.

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Zytiga Did Not Extend Survival In Key Clinical Trial -- Yet
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This morning, Johnson & Johnson announced that an independent committee had decided to stop a clinical trial of its drug Zytiga in men whose prostate cancer had spread but isn’t causing much pain or other symptoms, leading shares of rival Dendreon to drop and those of Medivation, another rival, to pop.

Here’s J&J’s explanation of the decision to stop the trial:

The Independent Data Monitoring Committee (IDMC) unanimously recommended unblinding the study based on a planned interim analysis in which differences in radiographic progression-free survival, overall survival, and secondary endpoints were observed that constitute evidence of clinical benefit as well as continued evidence of favorable safety in patients receiving abiraterone acetate plus prednisone as compared to those receiving placebo plus prednisone. Based on these results, the IDMC also recommended that patients in the placebo arm be offered treatment with ZYTIGA.

via Study Unblinded: ZYTIGA® (abiraterone acetate) Plus Prednisone for Asymptomatic or Mildly Symptomatic Chemotherapy-Naïve Patients with Metastatic Castration-Resistant Prostate Cancer.

Importantly, this does not say that the drug was proved to increase overall survival. And, according to Johnson & Johnson spokeswoman Kellie McLaughlin. She says:

They reached statistical significance on a primary endpoint which was R-PFS and on all secondary endpoints and there was a strong trend for overall survival, all of which constituted compelling evidence of clinical benefit. And that led to the IDMC’s recommendation to unblind the trial. The survival data will continue to mature.

This does not mean that Zytiga will not turn out to improve survival for these patients. There have been other examples where studies stopped for progression free survival (living without your cancer getting worse) have resulted in survival advantages. But the effect could be muted because patients in the placebo group now have the option of taking Zytiga, too.

http://www.forbes.com/sites/matthewherper/2012/03/08/zytiga-did-not-extend-survival-in-key-clinical-trial-yet/