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A new amyloid-lowering therapy is now available for people living with early Alzheimer's disease with the TGA registration of LEQEMBI (lecanemab)

Eisai Australia and Biogen Australia

Key Facts:

VIDEO NEWS RELEASE AVAILABLE

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MELBOURNE and SYDNEY, 24 September 2025 – Eisai Australia and Biogen Australia have announced today that the Therapeutic Goods Administration (TGA) has registered the use of LEQEMBI^® (lecanemab) in Australia as an amyloid-lowering therapy in adult patients for the treatment of Mild Cognitive Impairment due to Alzheimer’s disease and Mild Alzheimer’s dementia (early Alzheimer’s disease) that are apolipoprotein E ε4 (APOE4) non-carriers or heterozygotes.^1,2 Beta amyloid evidence consistent with Alzheimer’s disease should be confirmed using a validated test prior to initiating treatment.¹

 

The APOE4 gene variant is a predisposing genetic factor for Alzheimer’s disease. Research has shown that approximately 85% of people diagnosed with early Alzheimer’s disease are APOE4 non-carriers or heterozygotes, meaning they have no copies (non-carriers), or one copy (heterozygotes) of the APOE4 gene.^5,6 LEQEMBI is not indicated for those who carry two APOE4 copies (homozygotes).¹

 

Australia becomes the latest country to register LEQEMBI for use. To date, 49 other countries including the United States and the 27 member countries of the European Union have registered LEQEMBI, with it currently under regulatory review in a further eight countries.⁷

 

The TGA registration of LEQEMBI is a significant development, providing a new treatment option for eligible people living with early Alzheimer’s disease, based on the results of a rigorous Phase 3 clinical trial.¹

 

Over 400,000 Australians are living with dementia, of which 60% or more may have Alzheimer’s disease – a progressive and irreversible neurodegenerative brain disease that impairs cognition, memory and function.^3,4 It is characterised by abnormal clumps or ‘plaques’ of the protein, beta amyloid, which form around the brain cells and interfere with normal cell functions.⁸ Mild Cognitive Impairment is a brain condition that can be caused by early Alzheimer’s disease, and involves subtle changes in memory and thinking.⁹

 

LEQEMBI is a monoclonal antibody that is administered in a specialised centre via a one-hour intravenous infusion every two weeks and targets the underlying pathology of Alzheimer’s disease.^1,2 LEQEMBI works by targeting and lowering toxic amyloid plaques that continuously accumulate in the brain in Alzheimer’s disease.^1,2

 

Cathy Roth OAM, Chairman of Professionals with Alzheimer’s (PALZ) Global, said this registration is welcome news for Australians diagnosed with early Alzheimer’s disease.

 

“The impact of Alzheimer’s disease on Australians living with this disease, their families and carers is profound. These Australians experience stigma, fear, and symptoms that affect their quality of life,” said Ms Roth.

 

“Early signs and symptoms of mild cognitive impairment, such as often losing things or forgetting important events,¹¹ may be seen as a normal part of ageing when they are not. Increased early detection, research, and new treatment options for early Alzheimer’s disease are all crucial to give Australians living with this disease, as well as those who sadly may face this diagnosis later in life, new opportunities to manage the progression of the disease.”

 

Leading geriatrician and dementia expert, Professor Michael Woodward, said the TGA registration of LEQEMBI is a significant step as it provides a new treatment option in Australia for people living with early Alzheimer's disease.

 

“With more than 812,500 Australians projected to be living with a form of dementia by 2054,¹¹ there is an urgent need for advances in the early diagnosis and treatment of Alzheimer's disease. The build-up of toxic amyloid plaques can occur up to 20 years before people may experience symptoms⁴, so early diagnosis creates greater opportunity to reduce the rate of cognitive and functional decline with new advances in treatment options,”¹² said Professor Woodward.

 

“The TGA registration of LEQEMBI for early Alzheimer’s disease is an important development in the way we treat this disease. It means we now have another amyloid-lowering therapy we can introduce in the right patients to target the underlying cause of Alzheimer’s disease, taking a more proactive approach to slow the cognitive decline associated with the disease. It’s an exciting time but there is work to be done in recalibrating the health system, its resources and focus to fully integrate these therapeutic advances into the effective management of early Alzheimer’s disease.”

 

According to Dr John Bower, Market Access and Medical Director at Eisai in Australia, the company is committed to making a meaningful difference to the management and care of people at all stages of Alzheimer’s disease

 

“Australians living with Alzheimer’s disease deserve to live their lives in whatever way is most meaningful and fulfilling to them. The TGA registration of this new medicine provides Australians living with early Alzheimer’s disease with a treatment option,” said Dr Bower.   

 

Monique Alves, Head of Medical Australia and New Zealand at Biogen Australia said, “Working with industry partners, researchers, experts and consumer organisations is important in finding new ways to improve identification, screening, early diagnosis and management of Alzheimer’s disease. This announcement is evidence of that and signals a significant step forward to better supporting Australians, their families and carers who are impacted by this disease.”

 

 

ENDS

This media release has been distributed by Palin Communications on behalf of Eisai Australia.

 

For all media enquiries, please contact:

Maya Ivanovic Palin Communications 0403 354 305 [email protected]

Karina Durham Palin Communications 0402 307 056 [email protected]

 

Disclosure Statement

Professor Woodward has served on Eisai advisory boards, for which compensation was received, and has also been involved in clinical trials sponsored by Eisai. In relation to this Eisai media announcement, no compensation was provided to Professor Woodward, and the opinions expressed are his own. Professor Woodward has been briefed by Eisai on the approved use of LEQEMBI.

 

References

1. Leqembi product information. Available at https://www.eisai.com.au/wp-content/uploads/2025/09/Leqembi_PI_AU_EN_Version_1.pdf
2. TGA registration, Leqembi. Available at https://www.tga.gov.au/news/news/tga-approves-registration-lecanemab-leqembi
3. Australian Institute of Health and Welfare. Dementia in Australia, prevalence of dementia. Available at https://www.aihw.gov.au/reports/dementia/dementia-in-aus/contents/population-health-impacts-of-dementia/prevalence-of-dementia. Accessed: June 2024
4. Alzheimer’s Association. What is Alzheimer’s Disease? Available at: https://www.alz.org/alzheimers-dementia/what-is-alzheimers. Last accessed June 2024
5. Lecanemab licensed for adult patients in the early stages of Alzheimer’s disease (UK registration). Available at https://www.gov.uk/government/news/lecanemab-licensed-for-adult-patients-in-the-early-stages-of-alzheimers-disease. Accessed: January 2025
6. Vasiliou, V., et al. The Role of Apolipoprotein E in Alzheimer’s Disease. Neuron. 2009 Aug 13;63(3):287-303. doi:10.1016/j.neuron.2009.06.026. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC3044446/#:~:text=The%20%CE%B54%20allele%20of%20apolipoprotein,has%20yet%20to%20be%20proven. Accessed: January 2025.
7. Austria and Germany to become the first markets in the European Union (EU) to launch LEQEMBI® (lecanemab). Available at https://www.eisai.com/news/2025/news202557.html. Accessed: September 2025
8. Dementia Australia, What is dementia? Available at https://www.dementia.org.au/about-dementia/dementia-my-family/age-16/what-dementia-16. Last accessed June 2024.
9. Dementia Australia, mild cognitive impairment (MCI). Available at https://www.dementia.org.au/brain-health/mild-cognitive-impairment-mci. Last accessed June 2024.
10. Leqembi consumer medicine information. Available at https://www.eisai.com.au/wp-content/uploads/2025/09/Leqembi_CMI_AU_EN_Version_1.pdf
11. Dementia Australia, Dementia in Australia – Prevalence Data Estimates 2024-2054. Available at https://www.dementia.org.au/sites/default/files/2024-03/Prevalence-Data-2024-Updates-All-forms-of-dementia.pdf Last accessed June 2024.
12. M Woodward. Mild cognitive impairment and mild dementia. Medicine Today 2022; 23(12): 55-59. Available at https://medicinetoday.com.au/mt/2022/december/regular-series/mild-cognitive-impairment-and-mild-dementia-recognition-diagnosis-and-management. Accessed: June 2024.
13. Van Dyck, C. H., Sabbagh, M. N., Yuan, Y., et al.. Lecanemab in Early Alzheimer’s Disease. N Engl J Med. 2023;388:9-21. doi:10.1056/NEJMoa2212948. Available at: https://www.nejm.org/doi/full/10.1056/NEJMoa2212948. Accessed: June 2024.

 

Additional notes for media

About LEQEMBI

LEQEMBI (lecanemab) is the result of a strategic research alliance between Eisai and BioArctic. LEQEMBI is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ). The Therapeutic Goods Administration (TGA) granted the approval of LEQEMBI in Australia for the treatment of early Alzheimer’s disease.² LEQEMBI should be initiated in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical trials, and who are apolipoprotein E ε4 (APOE4) non-carriers or heterozygotes. There are no safety or effectiveness data on initiating treatment at earlier or later stages of the disease than were studied.

 

The approval of LEQEMBI was primarily based on Phase 3 data from Eisai’s global, placebo-controlled, double-blind, parallel-group, randomized Clarity AD clinical trial, which met its primary endpoint (change from baseline in the Clinical Dementia Rating Sum of Boxes [CDR-SB] at 18 months) and all key secondary endpoints with statistically significant results. The data also demonstrates that 95% of patients who completed the core study (18 months) chose to continue in the open-label extension study (OLE).¹³ In the indicated population (APOE4 non-carriers and heterozygotes), LEQEMBI was associated with significantly less decline on measures of cognition and function than placebo over a period of 18 months; including 33% less decline on the primary endpoint, the CDR-SB (p<0.00001: least squares mean difference of 0.58 on CDR-SB between the two groups at 18 months).¹ In the indicated population, the most common adverse reactions are infusion-related reaction (26%), ARIA-H (combined cerebral microhaemorrhages, cerebral macrohaemorrhages, and superficial siderosis) (13%), headache (11%), and ARIA-E (oedema/effusion) (9%). Full results of the Clarity AD study were presented at the Clinical Trials on Alzheimer's Disease (CTAD) 2022 conference and simultaneously published in the peer-reviewed medical journal The New England Journal of Medicine (New Window) on November 29, 2022.

 

A range of subcutaneous lecanemab doses are being evaluated in the Clarity AD (Study 301) open-label extension. In 2025, the FDA approved LEQEMBI subcutaneous injection for maintenance dosing (after 18 months) for the treatment of early Alzheimer’s Disease.

 

Since July 2020 the Phase 3 clinical study (AHEAD 3-45) for individuals with preclinical AD, meaning they are clinically normal and have intermediate or elevated levels of amyloid in their brains, is ongoing. AHEAD 3-45 is conducted as a public-private partnership between the Alzheimer's Clinical Trial Consortium that provides the infrastructure for academic clinical trials in AD and related dementias in the U.S, funded by the National Institute on Aging, part of the National Institutes of Health, Eisai and Biogen. Since January 2022, the Tau NexGen clinical study for Dominantly Inherited AD (DIAD), that is conducted by Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), led by Washington University School of Medicine in St. Louis, is ongoing and includes lecanemab as the backbone anti-amyloid therapy.

 

SAFETY SUMMARY

 

Common side effects of LEQEMBI include headaches. Serious side effects include hypersensitivity to the ingredients, temporary and sometimes serious swelling and/or bleeding in the brain (ARIA) and areas of bleeding in the brain.¹⁰

 

In the Phase 3 trial, the most common side effect with LEQEMBI was infusion-related reactions, which can occur during or shortly after the infusion, and which most frequently happen with the first dose.¹ Your healthcare professional will monitor you after your infusion for infusion-related reactions.¹⁰

 

Monoclonal antibodies, like LEQEMBI, target clumps of beta amyloid in the brain. These treatments can sometimes cause a side effect where swelling (ARIA-E) or bleeding (ARIA-H) occurs in the brain. This side effect is known as Amyloid Related Imaging Abnormalities or “ARIA”. ARIA is a side effect that does not usually cause any symptoms but serious symptoms can occur. ARIA is most commonly seen as temporary swelling in areas of the brain that usually resolves over time. Some people may also have small spots of bleeding in or on the surface of the brain, and infrequently, larger areas of bleeding in the brain can occur. Most people with this type of swelling in the brain do not get symptoms, however some people may have symptoms, such as: headache, confusion, dizziness, vision changes, nausea, difficulty walking, and seizures. Your healthcare provider will perform magnetic resonance imaging (MRI) scans before and during your treatment with LEQEMBI to monitor for signs of ARIA.¹⁰

 

LEQEMBI is not to be used if you have two copies of a genetic risk factor known as ApoE ε4, as there is a higher chance of experiencing the side effect, ARIA. Before treatment your doctor will discuss genetic testing for ApoE ε4 and what this will mean for you.¹⁰

 

Some medicines can increase the risk for larger areas of bleeding in the brain in patients taking LEQEMBI. Talk to your healthcare provider to see if you are on any medicines that increase this risk. Do not use LEQEMBI if you are receiving medicines (called anticoagulants) to prevent blood clots.¹⁰ Because ARIA-E can cause focal neurologic deficits that can mimic ischemic stroke, treatment used to dissolve blood clots should be carefully considered in patients on LEQEMBI.¹

 

This summary provides basic information about LEQEMBI and does not include all information known about this medicine. Read the information given to you about LEQEMBI. This information does not take the place of talking with your healthcare provider. Your healthcare provider is the best person to help you decide if LEQEMBI is right for you.

 

For a copy of the Consumer Medicine Information (CMI) for LEQEMBI please ask your healthcare professional or view online at https://www.eisai.com.au/wp-content/uploads/2025/09/Leqembi_CMI_AU_EN_Version_1.pdf

About the Collaboration between Eisai and Biogen for AD

Eisai and Biogen have been collaborating on the joint development and commercialization of AD treatments since 2014. Eisai serves as the lead of LEQEMBI development and regulatory submissions globally with both companies co-commercializing and co-promoting the product and Eisai having final decision-making authority.

 

About the Collaboration between Eisai and BioArctic for AD

 

About Eisai Co., Ltd.

Eisai's Corporate Concept is "to give first thought to patients and people in the daily living domain, and to increase the benefits that health care provides." Under this Concept (also known as human health care (hhc) Concept), we aim to effectively achieve social good in the form of relieving anxiety over health and reducing health disparities. With a global network of R&D facilities, manufacturing sites and marketing subsidiaries, we strive to create and deliver innovative products to target diseases with high unmet medical needs, with a particular focus in our strategic areas of Neurology and Oncology.

 

In addition, we demonstrate our commitment to the elimination of neglected tropical diseases (NTDs), which is a target (3.3) of the United Nations Sustainable Development Goals (SDGs), by working on various activities together with global partners.