What Is Leqembi, and Why Does It Matter?
Leqembi (lecanemab-irmb) is a prescription medicine approved to treat early stages of Alzheimer's disease, such as mild cognitive impairment or mild dementia. The recent FDA approval of Leqembi IQLIK (pronounced "I Click") introduces a once-weekly, under-the-skin injection that can be taken at home. It offers a more convenient option for patients to continue treatment after completing 18 months of intravenous (IV) therapy. Leqembi also can be taken as a once-monthly IV infusion at a clinic for continuing therapy.
Leqembi is a type of medicine called a monoclonal antibody, which is designed to target and help clear harmful protein clumps in the brain called amyloid beta plaques and protofibrils. These protein buildups are believed to damage brain cells, leading to memory loss and thinking problems.
What makes Leqembi different from many other treatments for Alzheimer's disease is that it works to treat the main cause of the disease, not just the symptoms. It's one of the few medicines that works to slow down disease progress by removing both plaques and protofibrils, which are thought to be especially harmful to brain cells.
Why Was It Approved?
The newer at-home Leqembi IQLIK shot was approved after a study showed that people who switched to the weekly injection after 18 months of IV treatment had the same benefits as those who stayed on IV therapy. Their brain scans and results from thinking tests were similar to those who kept getting the IV form. The safety of the under-the-skin Leqembi shot was similar to that of the IV version; however, fewer than 1% of people who received the weekly injection showed systemic (whole-body) side effects, compared to 26% of those on IV infusions.
The most common side effects include reactions at the time of treatment, temporary swelling in some areas of the brain with or without small spots of bleeding, and, rarely, large bleeding called amyloid-related imaging abnormalities (ARIA) and headaches. ARIA mostly happen in the first six months of IV initiation therapy and usually don't cause symptoms, although serious and life-threatening events and even death may occur. With the Leqembi IQLIK shot, fewer than 1% of people had systemic side effects like fevers, tiredness, or headaches, and about 11% had mild skin reactions such as pain, redness, swelling, bruising, or itching where the shot was given.
What Do I Need to Know?
After 18 months of IV treatment, you may be able to switch to the once-weekly at-home injection for maintenance therapy. It takes about 15 seconds for you or your caregiver to inject Leqembi IQLIK under your skin, usually in the front of your thighs or the stomach area (abdomen). Always change the injection site for your next weekly shot. If you miss a dose, take it within six days of the missed dose and then resume your regular weekly schedule for the next dose.
Before starting Leqembi, your health care provider will do a brain MRI to check for amyloid beta and may test for a gene called ApoE ε4 to assess your risk of ARIA, which can cause swelling or bleeding in your brain. Your health care provider may also recommend more MRIs and close monitoring, especially during the first 14 weeks of treatment, to watch for ARIA.
You should not use Leqembi if you've had a serious allergic reaction – such as swelling or trouble breathing – to it or to any of its ingredients. Tell your health care provider about all medicines you take, including over-the-counter products and supplements, especially if you take blood thinners such as aspirin or have a history of bleeding in the brain.
It is not known whether Leqembi can harm an unborn baby or pass into breast milk. If you are pregnant, planning to become pregnant, or are breastfeeding, talk to your health care provider.
Most people with ARIA do not have any symptoms, but if you are having headaches, confusion, dizziness, nausea, changes in your vision, or trouble speaking, walking, or moving, contact your health care provider right away, as these may be early signs of ARIA.