US FDA Approves New Alzheimer Treatment
Today, under the Accelerated Approval Pathway, the US Food and Drug Administration (FDA) has approved lecanemab-irmb (LEQEMBI) 100 mg/mL injection for intravenous use, a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble ("protofibril")* and insoluble forms of amyloid beta (Aβ) for the treatment of Alzheimer's disease (AD). The approval of the drug from Eisai Co., Ltd. and Biogen Inc. is based on Phase 2 data that demonstrated that LEQEMBI reduced the accumulation of Aβ plaque in the brain, a defining feature of AD. Using the recently published data from the large global confirmatory Phase 3 clinical trial, Clarity AD, Eisai will work quickly to file a Supplemental Biologics License Application (sBLA) to the FDA for approval under the traditional pathway.
LEQEMBI is indicated for the treatment of Alzheimer's disease in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical trials. The recommended dosage of LEQEMBI is 10 mg/kg administered intravenously once every two weeks to eligible patients with confirmed presence of Aβ pathology prior to initiating treatment. Enhanced clinical vigilance for amyloid-related imaging abnormalities (ARIA) is recommended during the first 14 weeks of treatment with LEQEMBI. Baseline, recent (within one year) brain MRI prior to initiating treatment with LEQEMBI and periodic monitoring with MRI prior to the 5th, 7th, and 14th infusions should be obtained.
The safety of LEQEMBI has been evaluated in 763 patients who received at least one dose of LEQEMBI in Study 201. The most common adverse reactions reported in at least 5% of patients treated with LEQEMBI 10 mg/kg biweekly (N=161) and at least 2% higher incidence than patients on placebo (N=245) were infusion-related reactions (LEQEMBI 20%; placebo 3%), headache (LEQEMBI 14%; placebo 10%), ARIA-E (LEQEMBI 10%; placebo 1%), cough (LEQEMBI, 9%; placebo, 5%) and diarrhea (LEQEMBI, 8%; placebo, 5%). The most common adverse reaction leading to discontinuation of LEQEMBI was infusion-related reactions that led to discontinuation in 2% (4/161) of patients treated with LEQEMBI compared to 1% (2/245) of patients on placebo.
Patients were excluded from enrollment in Study 201 for baseline use of anticoagulant medications. Antiplatelet medications such as aspirin and clopidogrel were allowed. Patients who received LEQEMBI and an antithrombotic medication (aspirin, other antiplatelets, or anticoagulants) did not have an increased risk of ARIA-H compared to patients who received placebo and an antithrombotic medication. The majority of exposures to antithrombotic medications were to aspirin; few patients were exposed to other antiplatelet drugs or anticoagulants, limiting any meaningful conclusions about the risk of ARIA or intracerebral hemorrhage in patients taking other antiplatelet drugs or anticoagulants. Because intracerebral hemorrhages greater than 1 cm in diameter have been observed in patients taking LEQEMBI, additional caution should be exercised when considering the administration of antithrombotics or a thrombolytic agent (e.g., tissue plasminogen activator) to a patient already being treated with LEQEMBI. Additionally, patients were excluded from enrollment in Study 201 for the following risk factors for intracerebral hemorrhage: prior cerebral hemorrhage greater than 1 cm in greatest diameter, more than 4 microhemorrhages, superficial siderosis, evidence of vasogenic edema, evidence of cerebral contusion, aneurysm, vascular malformation, infective lesions, multiple lacunar infarcts or stroke involving a major vascular territory, and severe small vessel or white matter disease. Caution should be exercised when considering the use of LEQEMBI in patients with these risk factors.
"The FDA's approval of LEQEMBI under the Accelerated Approval pathway is an important milestone in Eisai's four decades of research in Alzheimer's disease and reflects our continued commitment to alleviating the burden of Alzheimer's disease for patients and their families. Eisai has made great efforts to understand the reality of the challenges and concerns facing patients and their families who are living in the various stages of Alzheimer's disease, and we are incredibly pleased to offer LEQEMBI as a new treatment option to help with the tremendous unmet needs of this community," said Haruo Naito, Chief Executive Officer at Eisai Co., Ltd. "The challenges of Alzheimer's disease reach beyond medical implications for patients and considerations for their families, but also impact society as a whole through reduced productivity, elevated social costs and anxiety. Upon receiving this Accelerated Approval, we will focus on providing important information on proper usage of LEQEMBI to healthcare professionals. Eisai will also engage with various payers to provide access to LEQEMBI, offer a patient support program, and will do its utmost to complete submission for traditional approval as soon as possible to serve more people living with early Alzheimer's disease."
"The approval of LEQEMBI provides new hope to patients with Alzheimer's disease. Patients at an early stage of the disease and their caregivers can now consider a new treatment option with their doctors. Our focus now is on the path forward, working alongside Eisai with the goal of making LEQEMBI available to patients who may benefit from this treatment as soon as possible," said Christopher A. Viehbacher, President and Chief Executive Officer of Biogen. "This approval is also a recognition of the many scientists and doctors who have, over many years, patiently and persistently worked to find a treatment for this highly complex disease. Eisai and Biogen have collaborated for nearly a decade to advance research to improve the lives of those suffering from Alzheimer's, and we know that this commitment must and will continue in the fight against Alzheimer's disease."