The European Medicines Agency (EMA) has refused to approve lecanemab, a drug designed to slow cognitive decline in the early stages of Alzheimer's disease, setting itself apart from regulatory bodies in the United States, Japan, China, South Korea, Israel, the United Arab Emirates and the United Kingdom where the drug has been approved. This decision has sparked debate among experts, particularly regarding the EMA's risk-benefit assessment and conflict-of-interest policies.
Risk-Benefit Miscalculation
According to a clinical neurochemist with 20 years of Alzheimer's research experience, the EMA may have overestimated the risks associated with lecanemab while underestimating its potential benefits. While approximately 3.5% of patients taking lecanemab may experience adverse effects like headaches or dizziness due to brain swelling or bleeding, these side effects are generally manageable and less common than initially feared, according to US clinicians. Moreover, genetic tests and MRI scans can help identify patients at higher risk, allowing clinicians to selectively administer lecanemab to lower-risk individuals. The potential benefits of lecanemab include providing patients with invaluable months or years of cognitive function, allowing them to spend quality time with loved ones before dementia progresses.
Conflict-of-Interest Concerns
Another point of contention is the EMA's approach to conflict-of-interest policies. The agency's exclusion of experts with ties to pharmaceutical or biotechnology companies from advisory meetings raises concerns about potential bias and limited access to crucial insights. While the intention is to prevent biased decision-making, it may inadvertently exclude knowledgeable researchers and clinicians at the forefront of their fields. For instance, an expert was excluded from an EMA advisory meeting after disclosing consultancy work for Eisai and Biogen, the makers of lecanemab. This level of engagement with drug companies, while potentially raising conflict-of-interest concerns, provides invaluable expertise in assessing new medicines. The FDA's conflict-of-interest policy, which focuses on financial or other interests that could be affected by committee work, may offer a more balanced approach.
The EMA's decision to reject a treatment for alcohol dependence in 2020, potentially influenced by specialists with ties to rival products, has prompted interim measures and increased scrutiny. However, some argue that a more nuanced approach, similar to the FDA's, could prevent the exclusion of leading experts in their respective fields.
Implications and Future Outlook
Eisai has appealed the EMA's decision, presenting the agency with a second opportunity to approve lecanemab. If the EMA maintains its rejection, individuals with early-stage Alzheimer's disease in Europe may face limited treatment options. Furthermore, a continued tightening of the EMA's conflict-of-interest policy could have broader implications for the approval of medicines across various diseases.
