Eli Lilly’s Donanemab Approved, China’s Alzheimer’s Treatment Enters “Dual Hero Era”

On December 18, Eli Lilly announced that its donanemab injection has been approved by the National Medical Products Administration of China for the treatment of mild cognitive impairment and mild dementia caused by Alzheimer’s Disease (AD). This marks another groundbreaking targeted drug for Alzheimer’s disease following the approval of lecanemab by Eisai earlier this year, signaling a new phase of “etiological treatment” in AD therapy.

The “Valley of Death” in Alzheimer’s Drug Development

The development of AD drugs has long been referred to as the “Valley of Death.” According to Scientific American, the failure rate of new AD drugs can be as high as 99.6%, far exceeding the 81% failure rate in the cancer field. Even pharmaceutical giants like Roche and Merck have faced setbacks in this area. This is mainly due to the unclear pathogenesis of AD, with the current mainstream theories being the Aβ protein hypothesis and the tau protein hypothesis.

In recent years, the development of antibody drugs based on the Aβ protein hypothesis has become a hot topic, with lecanemab and donanemab gaining approval through clinical validation supported by this theory.

Competition Between Donanemab and Lecanemab: Two Paths

Although both target Aβ protein, donanemab and lecanemab have different mechanisms of action. Lecanemab mainly targets Aβ oligomers and protofibrils, which are intermediate steps in the formation of Aβ plaques. In contrast, donanemab directly targets Aβ plaques, aiming to improve patients’ conditions by clearing the deposited plaques.

However, this targeting mechanism has also led to a higher incidence of amyloid-related imaging abnormalities (ARIA) in clinical settings for donanemab. Data shows that the rate of ARIA with donanemab is as high as 31.4%, significantly exceeding the 17.3% rate for lecanemab. Nonetheless, the FDA advisory committee unanimously believes that donanemab’s efficacy is significant, with benefits outweighing risks.

Significant Efficacy and Market Prospects

In phase III clinical trials, donanemab demonstrated significant efficacy: after 18 months of use, the average reduction in amyloid plaques was 84%, compared to just 1% in the placebo group. Additionally, the drug does not require lifelong use, with half of the patients meeting the discontinuation criteria within 12 months.

With the approval of donanemab, AD patients have gained a new treatment option. The number of global AD patients continues to rise, expected to reach 78 million by 2030 and exceed 139 million by 2050. This enormous demand makes the AD drug market a focal point for competition among major pharmaceutical companies.

According to financial reports from Eisai and Boehringer Ingelheim, global sales of lecanemab are projected to reach $370 million in the fiscal year 2024. Although lecanemab faced safety concerns in Europe, it was approved after a re-evaluation, further underscoring the urgent demand for new drugs among patients.

The launch of donanemab is bound to inject new vitality into this market. With the continuous emergence of innovative drugs, the treatment outlook for AD patients is gradually improving.