Leqembi Shows Long-Term Benefits in Slowing Alzheimer's Progression

Biogen and Eisai's anti-amyloid antibody Leqembi (lecanemab) has demonstrated significant long-term efficacy in slowing the progression of Alzheimer's disease, according to new data presented at the Alzheimer's Association International Conference in Toronto. The results, stemming from the open-label extension phase of the Clarity AD study, provide compelling evidence for the sustained benefits of Leqembi treatment over a four-year period.

Extended Cognitive Benefits

The long-term data reveal that patients treated with Leqembi for four years maintained cognitive function significantly better than the expected natural course of Alzheimer's disease. Compared to the projected decline documented in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort, Leqembi-treated patients scored 1.75 points higher on the Clinical Dementia Rating scale after four years of treatment.

This improvement was even more pronounced than the three-year data, which showed a 1.01-point advantage over the expected decline. These results suggest that Leqembi not only slows disease progression but also helps patients remain in the earlier stages of Alzheimer's for a longer period.

Tau Protein Substudy Results

In a tau protein substudy of Clarity AD, 69% of patients with early-stage Alzheimer's demonstrated improvements or no decline in clinical scores after four years of Leqembi treatment. This finding further supports the drug's ability to modify the course of the disease and potentially provide sustained benefits over the long term.

Market Performance and Future Outlook

Despite being the first fully approved anti-amyloid antibody therapy for Alzheimer's disease, Leqembi initially faced challenges in market uptake, particularly in the United States. However, recent reports indicate a positive shift in its commercial performance.

Eisai's third-quarter report for the 2024 fiscal year noted a 30% quarter-on-quarter growth for Leqembi, a trend described as "steady" by analysts at Jefferies. In the United States, approximately 13,500 patients are now receiving Leqembi treatment, surpassing earlier expectations.

With sales gaining momentum, Biogen and Eisai are refocusing their promotional efforts on the clinical benefits of Leqembi. Biogen CEO Chris Viehbacher emphasized the opportunity to expand the prescriber base, stating, "I think now we can actually focus a lot more on the value proposition and treating patients."

As Leqembi continues to demonstrate long-term efficacy and gains traction in the market, it may play an increasingly significant role in the management of early-stage Alzheimer's disease, offering hope to patients and their families in the ongoing battle against this devastating condition.