The aducanumab drama continues to continue

As we discussed back in December 2019, Biogen has now filed with the FDA their application for approval of aducanumab.  You will recall that the monoclonal antibody treatment initially failed its phase three trial, but Biogen reevaluated the test data and concluded the drug was effective.  You will also recall from Beating the Dementia Monster that I had auditioned for the phase three trial but was screened out.

Out of fear of adverse effects on test subjects (brain micro-hemorrhages), Biogen reduced the dose part way through the trial.  After first concluding that the drug had failed the trial, they later re-evaluated the data with a focus on only results unaffected by the dose change.  They claim that these results confirm that the drug is actually effective.  Will the FDA agree?  We shall see. 

The biggest obstacle for Biogen will be to convince everyone that they don't need to start over with the phase three trial.  The argument for a do-over is that they didn't complete the trial, and the evidence for the drug's effectiveness is weak.  My perception is that the argument for going straight to market is that the safety risks are reasonably well understood, and that the need for something ... anything ... that will actually address the disease mechanisms is more significant than any call for caution.

Aducanumab is one of several drugs that have been shown to actually remove amyloid plaques from the brain.  These plaques are a consequence of the progression of Alzheimer's disease.  They appear to inhibit the flow of information in the brain which affects memory and cognition.  They also appear to kill brain cells.  But it's not clear that removing the plaques improves cognition or slows progress of the disease.

Biogen claims that their data shows aducanumab slows progress of the disease and improves cognition.  (They don't claim that it "cures" Alzheimer's disease.)  We'll see if the FDA agrees.