Few early Alzheimer’s patients eligible for new drug treatments.

Few early Alzheimer's patients eligible for new drug treatments.

Lack of Accessibility to Monoclonal Antibody Drugs for Alzheimer’s Patients



In recent years, there have been significant advancements in the development of new monoclonal antibody treatments for Alzheimer’s disease. However, a study published in the journal Neurology reveals that only a small percentage of individuals in the early stages of the disease are eligible for these drugs. This lack of accessibility raises concerns among experts, as early treatment is crucial for managing Alzheimer’s effectively.

The Ineligibility Issue

According to the research, a meager number of people with early-stage Alzheimer’s meet the criteria for treatment with monoclonal antibody drugs such as aducanumab and lecanemab. The clinical trials for these drugs had stringent inclusion and exclusion criteria, resulting in a limited pool of eligible candidates. As a result, the findings of the trials only apply to a small proportion of Alzheimer’s patients.

The lead author of the study, Maria Vassilaki, PhD, stresses the importance of ensuring accurate selection criteria for these drugs. She explains that only a small percentage of older individuals with early cognitive impairment due to Alzheimer’s may be suitable candidates for treatment with monoclonal antibodies for amyloid-β in the brain. This limitation highlights the need for further research to examine the safety and efficacy of these therapies in larger and more diverse populations.

Understanding the Study

The study involved 237 participants aged between 50 and 90, all experiencing mild dementia or cognitive impairment. Brain scans revealed increased amounts of amyloid-β plaques, a significant indicator of Alzheimer’s disease. These individuals were then evaluated based on the inclusion and exclusion criteria for the monoclonal antibody drugs lecanemab and aducanumab.

The results revealed that while 47% of the participants met the inclusion criteria for the lecanemab trial, applying the exclusion criteria reduced the eligible percentage to a mere 8% (19 people). Similarly, only 5% (12 individuals) of those studied would have been eligible for the aducanumab trial after considering the inclusion and exclusion criteria. Factors such as cardiovascular disease, stroke, a history of cancer, brain injuries, and uncontrolled high blood pressure were among the reasons for ineligibility.

The research findings emphasize that clinical trial participants tend to be healthier than the general population, which further narrows down the pool of eligible candidates. Therefore, it is vital to conduct more extensive research to determine the safety and efficacy of monoclonal antibodies in a broader and more diverse population.

How Monoclonal Antibody Drugs Work

Monoclonal antibodies target the amyloid-β plaques in the brain, which are a significant pathological hallmark of Alzheimer’s disease. Timing is critical in the treatment of Alzheimer’s with these drugs. As amyloid deposits occur 15 to 20 years before the onset of clinical symptoms, early intervention is crucial for maximizing the benefits of the drugs.

Dr. Sharon Sha, a clinical professor of neurology at Stanford University, emphasizes the need to administer these drugs in the early stages of the disease, as late-stage treatment may not yield significant benefits. The clinical trials that led to the FDA approval of aducanumab and lecanemab primarily included individuals in the early stages of Alzheimer’s. Therefore, research is required to explore alternative treatment options for patients in moderate to late stages of the disease.

Challenges in Accessing Alzheimer’s Drugs

Dr. David Merrill, a geriatric psychiatrist, raises concerns about the limited accessibility of monoclonal antibody treatments for the majority of Alzheimer’s patients. He underscores the minuscule chances of an average patient being eligible for these treatments, which hampers their ability to benefit from the drugs. Merrill highlights the importance of considering various factors besides removing amyloid from the brain to address the causes of dementia and slow down the disease’s progression. For instance, many Alzheimer’s patients have microbleeds and unstable medical conditions, making the removal of amyloid potentially risky.

The Need for Further Research

The study also emphasizes the necessity of conducting further research on a broader range of individuals. Black and Hispanic populations, who have a higher likelihood of experiencing Alzheimer’s or other forms of dementia, are notably underrepresented in clinical trials. This lack of representation hinders efforts to determine the drugs’ effectiveness in different patient groups.

Dr. Sharon Sha acknowledges that enrolling individuals from diverse backgrounds in clinical trials is challenging due to factors such as limited access to trial centers and health comorbidities. To ensure the effectiveness of Alzheimer’s treatments for all patients, it is crucial to address these barriers by expanding the inclusion of broader communities in both clinical trials and clinical care.


While new monoclonal antibody drugs hold promise for managing Alzheimer’s disease, the current lack of accessibility to these treatments for a significant portion of patients is a serious issue. The restrictive criteria applied in clinical trials limit the pool of eligible candidates. As a result, it is vital to conduct further research in more diverse populations to assess the safety and efficacy of these drugs. Additionally, efforts must be made to address the underrepresentation of minority groups in clinical trials to ensure equitable access to Alzheimer’s treatments.