n Wednesday, Biogen made an important announcement about its Alzheimer’s program, the one that puts billions of dollars and millions of hopes on the line. But it didn’t arrive via press release, and it wasn’t detailed in a filing with the Securities and Exchange Commission. Instead it was spoken softly by Dr. Al Sandrock, Biogen’s chief medical officer, before an audience of investors in New York.
“We did see more variability on the primary endpoint than assumed when we did the initial sample size estimations,” Sandrock said of two trials on aducanumab, the company’s all-important Alzheimer’s therapy. “So we decided to increase the sample size to maintain 90 percent power.”