Long-term Benefits of Alzheimer’s Drug Leqembi Demonstrated in New Study

The Alzheimer’s drug Leqembi has shown promising long-term benefits in slowing disease progression, according to new data released by Eisai, a Japanese drugmaker. The study, presented at the Alzheimer’s Association International Conference, highlights the importance of continued treatment for sustained cognitive and functional benefits.

Key Findings from the Study

1. Disease Progression Slowed Over Three Years:
   • Patients on Leqembi experienced a slower progression of Alzheimer’s disease over three years.
   • Stopping treatment led to a worsening of the disease, reinforcing the need for ongoing therapy.
2. Reduced Adverse Side Effects:
   • Side effects such as brain bleeding and swelling decreased after six months of treatment, addressing major concerns that have hindered the drug’s approval in Europe.
3. Efficacy and Safety Data:
   • This study provides the longest available efficacy and safety data on Leqembi, adding to the 24-month data released previously.
4. Mechanism of Action:
   • Leqembi is a monoclonal antibody targeting amyloid plaques in the brain, a hallmark of Alzheimer’s disease. It also clears protofibrils, the building blocks of amyloid plaque.
5. Importance of Early and Sustained Treatment:
   • Early and continuous treatment with Leqembi is crucial for maintaining cognitive function and slowing disease progression.
6. Potential for Maintenance Dose:
   • Eisai suggests that patients may eventually switch to a maintenance dose after 18-24 months of initial treatment, possibly reducing the frequency of infusions.
7. Regulatory Approval for New Administration Methods:
   • Eisai and Biogen are seeking approval for a once-monthly infusion of Leqembi and an injectable form that can be administered at home, potentially improving patient convenience and adherence.

Detailed Study Insights

• Phase Three Trial (Clarity AD):
  • Examined three groups: continuous Leqembi treatment for three years, a placebo group for 18 months followed by Leqembi, and a group with no treatment.
  • The continuous treatment group showed the slowest cognitive decline.
  • Those who switched from placebo to Leqembi also benefited, but their disease progression was worse compared to those who started Leqembi earlier.
• Sub-study on Tau Protein:
  • Patients with low levels of tau protein (indicative of early-stage Alzheimer’s) showed significant benefits.
  • 59% of these patients did not see their disease progress after three years, and over half saw an improvement.
• Phase Two Trial (Study 201):
  • Patients who stopped Leqembi reverted to the cognitive decline rate of the placebo group during a gap period.
  • This underscores the necessity of continuous treatment even after initial plaque removal.

Implications for the Future

Leqembi’s long-term benefits highlight its potential as a critical treatment in managing Alzheimer’s disease. The study suggests that early intervention and sustained treatment are key to maximizing its benefits. The move towards more convenient administration methods could further enhance patient adherence and outcomes. As the prevalence of Alzheimer’s continues to rise, these findings offer hope for improved management of this challenging condition.