Biogen ... or Eli Lilly?

The news about Alzheimer's disease drug trials has been dominated by Biogen's monoclonal antibody, aducanumab.  But it's not the only show in town, as we discussed back in January.   There has been increasing anticipation regarding that other monoclonal antibody, donanemab, which has continued to show promise in clinical trials and may be more effective.  As we've discussed before, there is skepticism regarding the effectiveness of aducanumab, and the FDA won't say anything about approving it until summer.  

In March, the New England Journal of Medicine published this article regarding the status of the donanemab trials.  They are in the second of the three phases of the trial, and the team conducting the trial (called Trailblazer) is reporting positive early results.  They are very optimistic about the ability of the donanemab to remove amyloid plaques and they are meeting their primary objective.  The primary objective is "a change from baseline in the Integrated Alzheimer's Disease Rating Scale (iADRS) Score."  iADRS is a composite tool that combines scores from a couple of other rating scales.  It is said to demonstrate acceptable psychometric properties and to be effective in capturing both disease progression and separation of placebo and active drug effect.  

However, results for the secondary objectives were "mixed."  Secondary objectives consisted of results of other cognitive assessments (including the mini mental status exam we discuss in Beating the Dementia Monster), as well as reduction in amyloid plaques, reduction in tau protein loading, and change in brain volume.  It's not clear to me which of these has been "mixed."

They reported, "In patients with early Alzheimer’s disease, donanemab resulted in a better composite score for cognition and for the ability to perform activities of daily living than placebo at 76 weeks, although results for secondary outcomes were mixed.  Longer and larger trials are necessary to study the efficacy and safety of donanemab in Alzheimer’s disease."

Just like aducanumab, donanemab will not "cure" Alzheimer's disease.  It will, at best, slow its progress.  It's not a pill, but requires intravenous infusions every four weeks.  But slowing the progress of Alzheimer's disease could still give someone several more years of enjoyable living, and testing these treatments is helping us to further understand this incredibly complex disease.