## FDA Approves Alzheimer’s Drug Leqembi for Traditional Use
### Introduction
On Thursday, the Food and Drug Administration (FDA) made a groundbreaking decision by granting traditional approval to the drug Leqembi, developed by Eisai and Biogen. This approval marks a significant milestone in Alzheimer’s disease research, as Leqembi is the first drug of its class to receive such recognition. The drug aims to slow down the progression of this neurodegenerative disease.
### The Role of Leqembi in Alzheimer’s Treatment
Leqembi is an antibody-based drug that targets amyloid beta, a protein known to play a crucial role in Alzheimer’s disease. In individuals with Alzheimer’s, the brain accumulates a misfolded form of amyloid, leading to the formation of plaques. These plaques, along with another misfolded protein called tau, contribute to the gradual destruction of the brain. Leqembi works by breaking down or preventing the formation of plaques, with the hope of halting or slowing cognitive decline.
### FDA’s Decision and Clinical Benefits
In January 2023, the FDA initially granted accelerated approval to Leqembi, based on indirect evidence of its impact on reducing amyloid plaque. However, companies are required to collect additional data to confirm a drug’s clinical benefits and obtain traditional approval. Leqembi successfully met this benchmark, demonstrating a 27% reduction in cognitive decline compared to a placebo in an 18-month clinical trial. Patients also exhibited improved daily functioning and lower levels of amyloid in their brains.
### Side Effects and Precautions
While Leqembi shows promise, it is essential to consider potential side effects. One common complication associated with anti-amyloid drugs is amyloid-related imaging abnormalities (ARIA), which can be diagnosed through MRI scans. ARIAs typically result from temporary brain swelling, but in some cases, they can indicate life-threatening bleeding. Although most ARIAs resolve without symptoms, there have been instances of fatalities linked to these drugs.
The risk of ARIA and severe ARIA appears to be higher in individuals carrying a specific Alzheimer-related mutation called ApoE ε4. Additionally, the use of blood thinners may increase the risk of severe brain bleeding in these patients. Consequently, Leqembi’s labeling will require doctors to test patients’ ApoE ε4 status before prescribing the drug and exercise caution when considering its use in those taking blood thinners.
### Contrasting Approvals: Leqembi vs. Aduhelm
The traditional approval of Leqembi stands in contrast to the controversy surrounding the approval of Aduhelm, another anti-amyloid drug developed by Biogen and Eisai. Aduhelm’s approval was met with criticism due to weak supporting data, leading to Medicare’s decision not to routinely cover the drug until further evidence of its benefits is collected. The FDA faced harsh criticism for its approval process, and the drug’s makers have delayed seeking approval elsewhere.
Unlike Aduhelm, Leqembi is not subject to the same Medicare policy. Furthermore, Leqembi’s current list price is half that of Aduhelm’s initial price, which contributed to widespread criticism. However, some researchers argue that Leqembi’s clinical benefits may be too modest to generate significant enthusiasm among patients and doctors. Nonetheless, the drug class as a whole is showing improvement, as evidenced by Eli Lilly’s donanemab, which demonstrated a 35% reduction in cognitive decline compared to a placebo in a recent large-scale trial.
In conclusion, the FDA’s traditional approval of Leqembi marks a significant advancement in Alzheimer’s disease research. While the drug shows promise in slowing cognitive decline, it is crucial to consider potential side effects and exercise caution in certain patient populations. The contrasting approvals of Leqembi and Aduhelm highlight the ongoing debate surrounding anti-amyloid drugs, but the field continues to evolve with promising results from other drugs like donanemab.
