Biogen bullish on prospects of Alzheimer's drug aducanumab

Biogen biologics plant in Denmark

Biogen’s Al Sandrock has given a bullish assessment of Alzheimer’s disease drug aducanumab. The head of R&D at Biogen thinks the drug works, despite it failing an interim analysis in phase 3.

Aducanumab looked to be dead in March when Biogen stopped phase 3 development in response to a failed futility analysis. However, Biogen delivered a surprise last month, revealing plans to file for FDA approval on the strength of an assessment it argues shows the futility analysis was incorrect. Biogen was unequivocal in its assessment of the wrongness of the futility analysis.

Sandrock expressed a similarly confident, clear-cut view at the Stat Summit.

“I believe the drug works. I don’t think the field has ever seen data like this,” Sandrock said. “I’m very excited about the prospect of getting the drug approved.”

Sandrock’s confidence reflects the positive aspects of the data set, such as the statistically significant improvement on a clinical dementia scale seen in the patients in one phase 3 who received the high dose of aducanumab. The improvement is a rare example of an encouraging efficacy signal in a phase 3 Alzheimer’s trial, a field beset by a long history of outright failures.

The potential problem for Biogen is that other aspects of the data paint aducanumab in a much less favorable light. In the other phase 3, placebo numerically outperformed the high dose of aducanumab on a clinical dementia scale and a test of cognitive function.

Biogen has an explanation for the discrepancies between the data generated in the two trials, pointing to the effect of protocol amendments to argue the positive results reflect the true efficacy of aducanumab. Where the FDA comes down on the merits of that explanation will go some way to shaping whether Biogen’s bid to resurrect aducanumab pays off.