The treatment landscape for early Alzheimer’s disease is changing rapidly. We’re moving beyond symptom management toward therapies that actually target the biology of the disease itself. One of the most important advances is lecanemab (brand name LEQEMBI) — a treatment that helps clear the amyloid plaques believed to play a major role in Alzheimer’s progression.
Until recently, lecanemab was given through an intravenous (IV) infusion every two weeks. While effective, this required frequent clinic visits and posed logistical challenges for many patients and families. The newest formulation — a subcutaneous (under-the-skin) injection called LEQEMBI IQLIK™ — now makes it possible to receive treatment at home through a simple, once-weekly injection. This marks a major step toward more accessible and sustainable long-term care.
How Lecanemab Works
Lecanemab is a type of antibody therapy that targets a toxic form of amyloid called protofibrils. By binding to these small, soluble clumps and the larger plaques they form, lecanemab helps the body clear amyloid from the brain. Over time, this slows the chain reaction of inflammation and nerve damage that contributes to memory loss and cognitive decline.
In clinical studies, patients receiving lecanemab showed slower decline in memory and function compared to those not on treatment — and brain scans confirmed measurable plaque reduction.
The Science Behind the New Subcutaneous Version
The subcutaneous (SC) version of lecanemab was designed to deliver the same benefits as the IV infusion, but with greater convenience and potentially fewer side effects.
Comparable Effectiveness: Weekly under-the-skin injections provide drug exposure equivalent to the standard IV infusion given every two weeks.
Steadier Levels: Because the medication enters the bloodstream more gradually, peak drug levels (which can contribute to side effects like brain swelling) are lower.
Better Tolerability: The new formulation maintains all the therapeutic benefits with a lower risk of infusion-related reactions and brain imaging abnormalities known as ARIA.
Clinical Results and Benefits
In long-term studies, the subcutaneous form has shown outcomes consistent with IV therapy — and, in some cases, even better amyloid clearance over time.
Brain Effects: At one year, patients receiving the subcutaneous dose had slightly greater amyloid reduction compared to IV.
Biomarkers: Blood tests reflected continued improvement in markers of brain inflammation and tau pathology.
Clinical Function: Across 48 months, patients maintained slower disease progression than expected, suggesting durable benefit over years of use.
Importantly, none of the patients receiving the approved 360 mg weekly subcutaneous dose experienced ARIA-E (a type of brain swelling sometimes seen with infusion therapy) during the first six months of treatment.
Safety and Tolerability
The subcutaneous formulation not only improves convenience — it also appears to enhance safety.
Lower ARIA Risk: Especially in patients with the APOE4 gene, which can increase susceptibility to ARIA.
Fewer Reactions: Less than 1% experienced systemic infusion-like symptoms compared to 26% with IV infusions.
Mild Local Effects: Some patients noticed mild redness or swelling at the injection site, which typically resolved on its own.
No New Safety Concerns: Antibody development against the drug remains rare, occurring in only 2–3% of individuals.
Practical Use and What to Expect
After completing the initial IV treatment phase (typically 18 months), patients can transition to at-home maintenance using the LEQEMBI IQLIK autoinjector. This device is designed for simplicity — most patients or caregivers can complete an injection in about 15 seconds.
Human factors testing confirmed that even those with mild cognitive changes could perform injections safely and effectively, often with minimal caregiver support.
Typical schedule:
Initiation: IV infusions every two weeks for 18 months
Maintenance: Weekly 360 mg subcutaneous injections at home, or optional IV infusion every four weeks
Why This Matters
The subcutaneous version of lecanemab doesn’t just represent a new delivery system — it represents a new philosophy of care. It enables treatment continuity without constant hospital or infusion visits, reduces transportation burdens, and allows families to reclaim valuable time.
At a system level, this innovation may reduce strain on infusion centers and lower overall healthcare costs. Models predict savings of up to $80,000 per patient over four years compared to ongoing IV therapy, largely due to decreased facility use and improved adherence.
What Patients and Families Should Know
Genetic Testing: APOE genotyping is recommended before starting therapy to assess ARIA risk.
Ongoing Monitoring: MRI scans remain part of care during early treatment, particularly in the IV phase.
Education and Support: Learning proper injection technique and understanding how to manage mild site reactions are key to success. Your care team will guide you through each step.
Looking Ahead
The subcutaneous form of lecanemab represents a major advance in the ongoing fight against Alzheimer’s disease. It combines clinical rigor with patient-centered design, offering an equally effective, safer, and more flexible treatment option. For many, it marks the beginning of a new era — one where disease-modifying therapy becomes part of daily life rather than an ongoing medical ordeal.
As we continue to learn and refine, our goal remains constant: to help each patient preserve cognitive health, independence, and quality of life for as long as possible.
