Contributed by Elizabeth Head, Josh Grill, and Ira Lott
People with Down syndrome are at high risk for developing Alzheimer disease beginning after the age of 40 years. This is due, in part, to the extra copy of chromosome 21, which contains the amyloid precursor protein gene and leads to higher production of beta-amyloid with age. Indeed, there is evidence that the overproduction of amyloid in Down syndrome is a strong driver of Alzheimer disease, which is why treatments targeting beta-amyloid could be impactful for this group of adults. In our current exciting times, which includes the first ever approval of an amyloid immunotherapy called aducanumab (Aduhelm), one would think that people with Down syndrome would benefit.
However, before a treatment can be known to be safe and effective, it must be tested in clinical trials. The clinical trials to assess the safety and efficacy of Aduhelm did not include people with Down syndrome. It will be critically important to have clinical trials dedicated to people with Down syndrome to assess this treatment and others like it. In particular, a strong focus on safety is needed. The side effects of Aduhelm, involving brain swelling, may be a major concern for people with Down syndrome given some differences in their brain physiology and in the way Alzheimer’s disease affects the brain. The good news is, there are several groups now (Alzheimer’s Clinical Trials Consortium for Down syndrome, ACTC TRC-DS and LuMIND) that are preparing for this exciting opportunity by assembling teams of volunteers with Down syndrome in advance, to rapidly implement clinical trials as soon as possible.
How does this relate to Medicare? Many people with Down syndrome are dependent upon Medicare for all access to care. There is a strong grassroots movement in the Down syndrome advocacy community (including the National Down syndrome Society), Down syndrome Medical Interest Group, the National Task Group on Intellectual Disabilities and Dementia Practices and LuMIND to urge the Centers for Medicare and Medicaid Services to cover treatment with Aduhelm in people with Down syndrome and Alzheimer’s. Notably, coverage for older people without Down syndrome and Alzheimer’s was preliminarily announced by Medicare to be highly limited (to the setting of new clinical trials).
While it is conceivable that the urgently needed trials of Aduhelm and drugs like it in people with Down syndrome could be covered by Medicare, there would also be challenges including whether placebo controls could be incorporated. While we strongly advocate for equal access to care and resources for people with Down syndrome and Alzheimer’s, broad access to new drugs for Alzheimer’s disease cannot be safely delivered to people with Down syndrome until careful and rigorous assessment of safety and efficacy have been performed. These trials need to be performed as soon as possible, so that we can understand whether these new medications hold promise for people with Down syndrome and Alzheimer’s.