Following accelerated approval in January, lecanemab (Leqembi) has now received full approval from the Food and Drug Administration (FDA) for the treatment of Alzheimer disease and should be initiated in patients with mild cognitive impairment or mild dementia. The drug does not stop Alzheimer's progression or reverse memory loss, but it does slow down the process. Lecanemab is administered by IV infusion every other week.
Alzheimer disease is a progressive disease where changes in the brain, including development of amyloid beta plaques and neurofibrillary (or tau) tangles, result in loss of neurons and their connections. These changes can affect a person's memory, thinking, and ability to live independently. The buildup of amyloid beta plaques is believed to be a major contributing factor to Alzheimer disease. Other contributing factors include age-related changes and genetic, environmental, and lifestyle factors. The exact cause of Alzheimer disease in most people is not known.1
Lecanemab is a monoclonal antibody that acts against aggregated soluble and insoluble forms of amyloid beta plaques in the brain and reduces them. It is the second drug in this class. Aducanumab (Aduhelm), the first such monoclonal antibody, received accelerated approval in 2021 but has not yet received full approval. Its accelerated approval was controversial, with the FDA's Advisory Panel for Peripheral and Central Nervous System Drugs declining to recommend approval because of a lack of adequate evidence demonstrating effectiveness (for more, see Drug Watch October 2021).
Similar to aducanumab, lecanemab can cause brain changes (amyloid-related imaging abnormalities), including brain swelling or intracerebral hemorrhage. A boxed warning notes these potential adverse effects, but states that they are usually asymptomatic and not serious. Patients should have magnetic resonance imaging of the brain at baseline and before the fifth, seventh, and 14th lecanemab infusions, and if any symptoms develop.
Evidence of lecanemab's effectiveness was based on data from the drug manufacturer's phase 3 multicenter, randomized, double-blind, placebo-controlled, parallel-group study that enrolled 1,795 patients. The primary efficacy outcome was change from baseline at 18 months in the Clinical Dementia Rating Scale Sum of Boxes score. Clinical decline, as measured by the scale, was decreased by 27% (although this reflects a very small score change). The FDA's Advisory Panel for Peripheral and Central Nervous System Drugs voted unanimously that the study findings demonstrated a statistically and clinically significant benefit of lecanemab in the treatment of early Alzheimer disease that outweighed the risk for brain changes and possible bleeding.
Patients and their families may have many questions for nurses about lecanemab, including about its cost and whether it will be covered by Medicare. Although the Centers for Medicare and Medicaid Services has agreed to cover lecanemab now that it is fully approved, there are some restrictions: the patient must be enrolled in Medicare, have paid the standard coinsurance, have been diagnosed with mild cognitive impairment or mild dementia from Alzheimer disease with documented amyloid beta brain plaques, and have a physician who participates in a qualifying registry and who is able to provide appropriate follow-up care.
Lecanemab is priced at $26,500 per year. This does not include the cost of brain imaging, medical visits, and administration. It is estimated that Medicare will need to pay between $2 billion and $5.1 billion a year to cover the cost of lecanemab.2 The cost for those on Medicare who do not have supplemental coverage could be significant. Some patients may find the biweekly administration, additional tests, and travel time for appointments too burdensome.
Nurses may find this National Institute on Aging video helpful in teaching patients and their families about Alzheimer disease: http://www.nia.nih.gov/health/video-how-alzheimers-changes-brain.
For complete prescribing information for lecanemab, go to http://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761269s001lbl.pdf.
REFERENCES