Eisai, a pharmaceutical company, announced promising initial results for an injectable version of the Alzheimer’s drug Leqembi, potentially offering a more convenient administration option for this antibody treatment. While this new injection method did not result in reduced rates of brain swelling and bleeding, which are among the most concerning side effects of Leqembi, it may still present a more user-friendly choice for patients and caregivers.
Leqembi, jointly produced by Eisai and Biogen, is a groundbreaking medication, as it is the first drug to demonstrate effectiveness in slowing the progression of Alzheimer’s in individuals at the early stages of the disease. In July, U.S. regulators approved an intravenous version of Leqembi, administered twice monthly, offering a method known as intravenous infusion. Eisai and Biogen now aim to obtain approval for a subcutaneous version of the drug, which would involve administering the drug via injection under the skin. This approach would grant patients and caregivers the freedom to administer Leqembi at home, eliminating the need for frequent visits to infusion centres, typically located in hospitals.
Eisai and Biogen have announced their intention to seek U.S. approval for subcutaneous Leqembi by the end of March.
The preliminary results, shared by Eisai, emanate from an extension to a late-stage clinical trial that initially supported the approval of intravenous Leqembi. This study explored subcutaneous doses of Leqembi, with a primary focus on evaluating the drug’s safety and its impact on a protein called amyloid, often referred to as plaque, which accumulates in the brain and is associated with Alzheimer’s disease.
The study revealed that a series of two injections administered once weekly yielded similar results after six months, concerning safety, drug concentration in the blood, and its efficacy in clearing brain plaque buildup, in comparison to the approved intravenous infusions administered twice monthly.
Moreover, the study highlighted that the injectable form of Leqembi was more effective at removing plaque than the intravenous formulation, achieving a 14% improvement. Blood concentration levels of the drug were also 11% higher in the subcutaneous Leqembi group.
Nevertheless, this new form still exhibited side effects known as amyloid-related imaging abnormalities (ARIA), including ARIA-E and ARIA-H, which can be associated with brain swelling and bleeding, sometimes leading to severe or even fatal outcomes in rare cases. Roughly 17% of patients receiving weekly injections experienced ARIA-E, while 13% of those receiving the drug via intravenous infusion encountered this issue. Additionally, 22% of patients receiving injections had ARIA-H, compared to 17% in the intravenous group.
The battle against Alzheimer’s disease remains a pressing concern as the number of affected individuals continues to rise. Presently, an estimated 6.7 million Americans aged 65 and older are living with Alzheimer’s, and this number is expected to reach nearly 13 million by 2050. Alzheimer’s and other forms of dementia combine to make it the third leading cause of death among seniors, surpassing breast cancer and prostate cancer combined. The disease often commences with mild memory loss but ultimately results in a profound impairment of an individual’s cognitive abilities and their capacity to perform daily tasks.
Alzheimer’s disease has been an exceptionally challenging condition to treat, with numerous drugs designed to target the disease failing in clinical trials. The significant cost and duration of research in this field have further complicated the development of effective treatments. Moreover, scientists have engaged in a continuous debate regarding the precise cause of the disease and the optimal targets for therapeutic drugs.
In conclusion, the pursuit of effective treatments for Alzheimer’s disease continues to be a significant medical challenge. The ongoing research and development of drugs like Leqembi, alongside various administration methods, signify progress in the quest to address this devastating condition. The promising results from the injectable version of Leqembi provide hope for the potential expansion of treatment options for Alzheimer’s patients, to enhance their quality of life and potentially slow the progression of the disease.
