Introduction

Eli Lilly has achieved a milestone with its Alzheimer’s drug Kisunla, recently approved by Japan’s health ministry. Donanemab (Kisunla) is an antibody drug designed to slow the progression of dementia symptoms. This approval marks Japan as the second major market for Kisunla, following its earlier approval in the United States. The drug is designed to treat early symptomatic Alzheimer’s disease (AD) in adults.

The Growing Need for Alzheimer’s Treatments in Japan

Japan’s ageing population shows the urgency for effective Alzheimer’s treatments. According to the Alzheimer’s Association, over 4.6 million people in Japan currently live with dementia. This number is expected to rise significantly, potentially surpassing five million by 2030. Alzheimer’s disease accounts for about 60-70% of dementia cases globally, making it a critical area for pharmaceutical innovation.

Eli Lilly’s Kisunla aims to address this need by targeting amyloid plaques in the brain, a hallmark of Alzheimer’s disease. The drug offers a new treatment option for patients with mild cognitive impairment (MCI) and mild dementia stages of AD, confirmed through amyloid pathology.

Clinical Trial Insights and Efficacy

The approval of Kisunla in Japan is based on robust data from the TRAILBLAZER-ALZ 2 phase III study. This study demonstrated that Kisunla slowed cognitive and functional decline by up to 35% compared to a placebo over 18 months. The drug also reduced the risk of progressing to the next clinical stage of the disease by up to 39%. These results are promising, particularly for patients in the early stages of Alzheimer’s.

Moreover, Kisunla has shown a significant reduction in amyloid plaques. On average, participants experienced an 84% reduction in these plaques at 18 months compared to the study’s start. This reduction aligns with the drug’s mechanism of action, which targets and clears amyloid plaques from the brain.

Competitive Landscape and Advantages

Kisunla is the second amyloid-targeting drug approved in Japan, following Eisai and Biogen’s Leqembi. However, Kisunla offers a unique advantage: it allows for finite dosing. Patients can discontinue treatment once amyloid plaques are no longer detectable via PET scans. This feature could lower treatment costs and reduce the burden on patients and healthcare systems.

In the TRAILBLAZER-ALZ 2 study, approximately 47% of participants completed treatment at 12 months, and 17% completed it at six months. This finite dosing contrasts with Leqembi, which requires bi-weekly intravenous (IV) administration. Kisunla’s monthly IV dosing regimen is less frequent, potentially enhancing patient compliance and convenience.

Future Outlook and Market Potential

The approval of Kisunla in Japan is a significant step for Eli Lilly, given the country’s rapidly ageing population. By 2035, individuals aged over 65 are expected to account for 32.3% of Japan’s population. This demographic shift highlights the growing need for effective Alzheimer’s treatments.

Eli Lilly’s stock performance has reflected this positive development. Year-to-date, the company’s shares have surged by 58.6%, outpacing the industry’s 22.4% rise. The Japanese market’s potential for Kisunla is substantial, with an estimated five million dementia patients by 2030, two-thirds of whom will likely have Alzheimer’s.

Despite these promising developments, the commercial success of Kisunla and similar drugs remains uncertain. Healthcare professionals have mixed views on their benefits and risks. While Kisunla has shown meaningful results, concerns about brain swelling and bleeding persist. These side effects, although mostly mild, are flagged with the FDA’s strongest “boxed” safety warning.

Conclusion

Eli Lilly’s Kisunla represents a significant advancement in Alzheimer’s treatment, particularly for Japan’s ageing population. The drug’s approval in Japan, following its earlier approval in the United States, highlights its potential to address the growing burden of Alzheimer’s disease. With its unique finite dosing feature and promising clinical trial results, Kisunla offers a new hope for patients and healthcare systems alike.

As the market for Alzheimer’s treatments continues to evolve, Kisunla’s performance will be closely watched. The upcoming third-quarter results will provide further insights into its initial uptake in the United States. For now, Eli Lilly’s Kisunla stands as a beacon of progress in the fight against Alzheimer’s disease.