Preclinical Alzheimer Disease Drug Development: Early Considerations Based on Phase 3 Clinical Trials

SUMMARY: The number of people in the United States living with Alzheimer disease (AD) is growing, resulting in significant clinical and economic impact. Substantial research investment has led to drug development in stages of AD before symptomatic dementia, such as preclinical AD. Although there are no treatments approved for preclinical AD, there are currently 6 phase 3 clinical trials for preclinical AD treatments. In this article, we review these clinical trials and highlight considerations for future coverage decisions. In line with the definition of preclinical AD, enrollment in these trials focuses on cognitively unimpaired patients that are at high risk of AD because of family history and then genetic testing or brain imaging. Enrollment in most of these trials also allows for younger patients, including those aged under 65 years. Primary clinical trial endpoints focus on cognition often 4 or more years after treatment. Secondary endpoints include other measures of cognition and function, as well as biomarkers. Review of these trials brings to light a few potential considerations when covering these new medications in the future. First, novel and potentially costly approaches involving genetic testing and/or positron emission tomography imaging may be needed to identify appropriate patients and should be developed efficiently. Second, the long duration of these clinical trials suggest that there may be a need for alternative payment approaches in the United States that encourage early payers to pay for a medication for which the long-term benefits may not be realized until after the beneficiary is no longer with the health plan. Third, the value of AD treatments may differ across populations, creating a potential role for indication-based or population-based contracting. Finally, considering the potentially high budgetary impact and little real-world evidence for a new drug class, payers and manufacturers may want to consider outcomes-based payment approaches and coverage with evidence development to mitigate uncertainty about the value of the treatment demonstrated in well-defined populations in clinical trials versus more heterogeneous real-world settings.