Clinical and Scientific Challenges to Effectiveness Studies Under Coverage with Evidence Development in Alzheimer's Disease.

The Centers for Medicare and Medicaid Services (CMS) has recently issued a national coverage determination for US Food and Drug Administration (FDA)-approved anti-amyloid monoclonal antibodies (mAbs) for the treatment of Alzheimer's disease (AD) under coverage with evidence development (CED). CED schemes are complex, costly, and challenging, and often fail to achieve intended objectives because of administrative and implementation issues. AD is a heterogeneous, progressive neurodegenerative disorder with complex care pathway that additionally presents scientific challenges related to the choice of study design and methods used in evaluating CED schemes. These challenges are herein discussed. Clinical findings from the US Veterans Affairs healthcare system help inform our discussion of specific challenges to CED-required effectiveness studies in AD.