Biotech Values

[biomaven0]

a) Jan 2010 (see dates in FDA Statistical Review): Pre-planned interim occurs for OS - Zytiga is VERY stat sig (<0.0001 when alpha was 0.0141).

b) Sept 2010: Final OS analysis for OS (kinda immaterial - but very stat sig)

c) Oct 2010: First J&J PR that they hit the interim (and thus x-over is allowed - but note PR is silent on the fact that they hit that interim 9 months ago).

By my reading the interim analysis did not occur in Jan 2010, but only in August 2010. I don't know why the delay between the cut-off date and the interim analysis date, but it's not something you can blame the FDA for. Given the long lag, an updated OS analysis before crossover seems quite reasonable - no reason to throw away potentially very informative data.

Study COU-AA-301 had a pre-planned interim superiority analysis of OS after occurrence of 534 deaths (67% information) with the O’Brien-Fleming type I error spending function for alpha adjustment (alpha for the interim analysis = 0.0124; alpha for the final analysis = 0.0462).
The IDMC reviewed the OS interim analysis of 552 deaths in August 2010. The nominal significance level for the interim analysis with 552 deaths was 0.0141 (two-sided) using the O’Brien-Fleming spending function. Given an observed p-value of <0.0001, the IDMC concluded that the prespecified efficacy boundary had been crossed and there was a significant OS improvement in favor of abiraterone acetate treatment. The IDMC recommended that the blinded portion of the study be terminated. The study COU-AA-301 was then amended (Amendment #3) to allow subjects in the placebo group to receive abiraterone acetate treatment.