Australia's Therapeutic Goods Administration (TGA) has rejected Eisai and Biogen's Alzheimer's disease therapy, Leqembi (lecanemab), stating that its efficacy does not outweigh the associated safety risks. The decision follows a similar recommendation against the drug by the European Medicines Agency (EMA) in July, casting doubt on the widespread adoption of this anti-amyloid treatment.
The TGA's decision was influenced by data from the pivotal Clarity AD trial, which showed a reduction in disease progression among patients treated with Leqembi compared to placebo. However, the regulator deemed this difference "not significant enough to provide a meaningful clinical benefit" relative to the risks of amyloid-related imaging abnormalities (ARIA), including brain swelling and bleeds.
Eisai Australia plans to request a reconsideration of the TGA's decision within 90 days. Dementia Australia, a patient advocacy group, expressed disappointment, stating that the decision would deprive Australians of the choice to access the potential benefits of the treatment. "While we respect the TGA as Australia's medicines regulator, should this decision be upheld it will be a blow to Australians who may be able to benefit from lecanemab," said Dementia Australia chief executive Prof Tanya Buchanan.
Global Regulatory Landscape
Leqembi has already been approved in the US, Japan, China, South Korea, Hong Kong, Israel, the UAE, and GB. However, access to the drug in the UK is uncertain due to cost-effectiveness concerns raised by the National Institute for Health and Care Excellence (NICE). NICE has indicated that the cost of the drug, along with the requirements for fortnightly infusions and monitoring for side effects, does not represent good value for the taxpayer.
Concerns Over Clinical Significance and Safety
Regulators in both Europe and Australia have expressed reservations about the clinical significance of Leqembi's benefits. The EMA noted that while most cases of ARIA were not serious, some patients experienced severe events, including large brain bleeds requiring hospitalization. The TGA also highlighted that the improvement in cognitive decline rates observed in clinical studies was not considered clinically meaningful.
The decision by the TGA was supported by independent expert advice from the TGA’s Advisory Committee on Medicines. The committee also expressed concern about the much-discussed side effect of ARIA — small brain bleeds, for which people who carry genetic biomarkers for Alzheimer’s and people on certain medications are especially at risk.
Eisai's Stance
Eisai and Biogen reported updated results from the Clarity AD trial in July, suggesting that the benefits of Leqembi treatment increase over time. Sales of Leqembi have been growing, reaching $40 million in the second quarter of the year, up from $17 million in the first quarter and $10 million for all of 2023. Despite these efforts, regulatory hurdles persist in key markets, raising questions about the future of Leqembi as a widely accessible treatment for Alzheimer's disease.
