Leqembi (lecanemab) is a recombinant humanized IgG1 monoclonal antibody that targets amyloid-beta aggregates, administered via intravenous infusion. First approved in the United States in 2023, this medication is indicated for the treatment of Alzheimer's disease in its early stages.

Indications for Leqembi (Lecanemab)

Core Therapeutic Indications

Leqembi is explicitly approved for the treatment of Alzheimer's disease, particularly in patients at the early stage of the disease.

In clinical trials, treatment was initiated in patient populations with mild cognitive impairment or mild dementia.

Patients at this stage typically meet the following characteristics:

A Clinical Dementia Rating (CDR) Global Score of 0.5 or 1.0.

A Memory Box Score of ≥ 0.5.

A Mini-Mental State Examination (MMSE) score ranging from 22 to 30.

A Wechsler Memory Scale-IV Logical Memory II subscale score that is at least 1 standard deviation below the age-adjusted mean.

Preconditions for Medication Use

It is mandatory to confirm the presence of amyloid-beta pathological features in patients through testing (e.g., PET imaging or biomarker detection).

Prior to treatment, ApoE ε4 genotype testing is required to assess the risk of amyloid-related imaging abnormalities (ARIA).

Specifications and Properties of Leqembi (Lecanemab)

Dosage Form and Packaging

Leqembi is a sterile, preservative-free, clear to opalescent, colorless to pale yellow injection, available in single-dose vials in two specifications:

500 mg/5 mL (concentration: 100 mg/mL)

200 mg/2 mL (concentration: 100 mg/mL)

Composition

Active Ingredient: Each milliliter contains 100 mg of lecanemab-irmb.

Excipients: Arginine hydrochloride (42.13 mg), histidine (0.18 mg), histidine hydrochloride monohydrate (4.99 mg), polysorbate 80 (0.50 mg), and water for injection. The pH value is approximately 5.0.

Storage Methods for Leqembi (Lecanemab)

Unopened Vials

Store in a refrigerator at 2°C to 8°C; freezing or shaking is strictly prohibited.

Keep in the original packaging to protect from light and avoid direct exposure to ultraviolet radiation.

Management of Diluted Solution

Must be diluted with 250 mL of 0.9% sodium chloride injection.

After dilution, infusion must be completed within 4 hours when stored under refrigeration (2°C–8°C) or at room temperature (≤ 30°C).

Requirements for Infusion Equipment

A terminal low-protein-binding 0.2-micron in-line filter must be used.

The infusion time should be controlled at approximately 1 hour, and the infusion line must be flushed after completion.