Alemtuzumab Injection (Lemtrada) is a CD52-directed cytolytic monoclonal antibody used for the treatment of relapsing forms of multiple sclerosis. Although it has demonstrated significant efficacy in controlling disease progression, great attention must be paid to its potential severe side effects and risks during medication administration.

Side Effects of Alemtuzumab Injection (Lemtrada)

Common Side Effects

(1) Skin-related reactions: Rash (53%), urticaria (16%), pruritus (14%).

(2) Systemic symptoms: Headache (52%), fever (29%), fatigue (18%), flushing (10%).

(3) Infectious diseases: Nasopharyngitis (25%), urinary tract infection (19%), upper respiratory tract infection (16%), herpes viral infection (16%), fungal infection (13%).

(4) Organ system impacts: Thyroid disease (13%), arthralgia (13%), limb pain (12%), dizziness (11%).

(5) Gastrointestinal symptoms: Nausea (21%), diarrhea (12%), vomiting (10%).

Severe Side Effects of Alemtuzumab Injection (Lemtrada)

Autoimmune Diseases

(1) Immune thrombocytopenia (incidence rate: 2%): Manifestations include abnormal bruising, subcutaneous petechiae, epistaxis, cerebral hemorrhage, etc.

(2) Glomerulonephritis (0.3%): Including anti-glomerular basement membrane disease (which can progress to end-stage renal disease).

(3) Thyroid dysfunction (36.8%): Including Graves' disease, hyperthyroidism/hypothyroidism; TSH levels need to be monitored every 3 months until 48 months after drug discontinuation.

Infusion Reaction Risks

(1) Severe hypersensitivity reactions: Including anaphylactic shock, angioedema, bronchospasm.

(2) Cardiovascular events: Myocardial ischemia, myocardial infarction, bradycardia/tachycardia.

(3) Delayed reactions: Some patients develop symptoms after 24 hours and require continuous observation.

Cerebrovascular Accidents

(1) Stroke risk: Ischemic or hemorrhagic stroke may occur within 3 days of medication administration.

(2) Carotid/vertebral artery dissection: Often accompanied by prodromal symptoms such as neck pain and sudden severe headache.

Precautions for Using Alemtuzumab Injection (Lemtrada)

Pre-Treatment Screening

(1) Complete blood count with differential, serum creatinine, routine urine test and urine cell count.

(2) Thyroid function test (TSH is recommended).

(3) Tuberculosis screening (performed in accordance with regional guidelines).

(4) Varicella-zoster virus antibody testing and necessary vaccination.

(5) Baseline skin examination (annual re-examination).

Infusion Management Specifications

(1) Facility requirements: Medical institutions equipped with emergency equipment and personnel.

(2) Time monitoring: Observe for at least 2 hours after infusion, and extend to 24 hours if necessary.

Preventive Medication Regimen

(1) High-dose corticosteroids: Before each infusion (3 days before the first course of treatment).

(2) Antiviral prophylaxis: Start on the first day of treatment and continue for ≥2 months or until CD4+ count ≥200/μL.