Blood Biomarkers Can Help Identify Treatment-Eligible Patients with Alzheimer’s Disease

Clinical trials continue to assess disease-modifying treatment for Alzheimer’s disease (AD), but should a treatment become available, there are concerns that a large number of patients would overwhelm the health care system, as dementia specialists are limited. A study presented at the 13th Clinical Trials on Alzheimer’s Disease Congress 2020 found that blood-based biomarker (BBBM) tests combined with the Mini-Mental State Exam (MMSE) could better identify patients who are eligible for a disease-modifying therapy at the primary care level.

Researcherssimulated the U.S. population of individuals aged 50 years and older over the course of 30 years, combining a disease progression model (cognitively normal to mild cognitive impairment [MCI] due to AD or due to other causes to dementia) and a system dynamics model for capacity constraints (specialist cognitive testing and confirmatory biomarker testing with positron emission tomography or cerebrospinal fluid).

They compared four scenarios for primary care evaluation: (1) cognitive screening only (MMSE), (2) BBBM only, (3) MMSE followed by BBBM if positive, and (4) BBBM followed by MMSE if positive.

The study found that the use of either MMSE or BBBM alone would result in a number of specialist referrals that is projected to continuously exceed capacity from 2020 to 2050. Combining MMSE and BBBM in either order would eliminate wait lists after the first three years. The projected number of correctly identified cases (i.e., true positive for MCI due to AD) will increase from approximately 480,000 for either MMSE or BBBM alone to approximately 600,000 for MMSE and BBBM combined on average each year.

Average total cost per year would be an estimated $7.2 billion for MMSE alone, $7.5 billion for BBBM alone, and $6.8 billion for MMSE and BBBM combined. Cost per correctly identified case will decline from approximately $15,000 for MMSE or BBBM alone to approximately $11,000 for a combination of MMSE and BBBM.

Combining BBBM with MMSE “would reduce wait times for specialist visits and diagnostic yield dramatically without increasing net cost,” the researchers concluded.

Presentation: OC41: Predicting the impact of blood biomarkers on cost and wait time in diagnosing treatment-eligible patients for Alzheimer’s disease. Presented at the 13th Clinical Trials on Alzheimer’s Disease Congress 2020, Nov. 4-7, 2020.