Lemtrada (Alemtuzumab)

• Lemtrada (alemtuzumab) is a disease‑modifying therapy indicated for the treatment of relapsing‑remitting multiple sclerosis, a chronic demyelinating condition of the central nervous system. By selectively depleting mature lymphocytes that drive autoimmune inflammation, the drug reduces the frequency of clinical relapses and slows the accumulation of disability. It is administered under specialist supervision as an intravenous infusion and is reserved for patients with active disease despite prior therapy.
• Relapsing‑remitting multiple sclerosis: reduces relapse frequency and delays disability progression in adult patients.

• Alemtuzumab binds with high affinity to the CD52 antigen expressed on the surface of mature T and B lymphocytes. This interaction triggers antibody‑dependent cellular cytotoxicity and complement‑mediated lysis, leading to profound and sustained depletion of circulating lymphocytes. The resulting immunomodulation diminishes the autoimmune attack on central nervous system myelin, thereby altering the disease course of multiple sclerosis.

Lemtrada is associated with a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Infusion‑related reactions such as flushing, rash, headache, or fever.
• Transient lymphopenia and mild neutropenia.
• Thyroid dysfunction, most often hyperthyroidism.
• Increased susceptibility to common infections.

Serious or Rare Side Effects

• Autoimmune cytopenias (e.g., immune thrombocytopenia, autoimmune hemolytic anemia).
• Severe infections, including opportunistic pathogens.
• Development of malignancies such as thyroid cancer.
• Cardiovascular events like stroke or myocardial infarction.
• Progressive multifocal leukoencephalopathy (PML).

Before initiating therapy, patients should be evaluated for infection risk and baseline laboratory values.

• Monitor blood counts: perform complete blood count with differential before each infusion and periodically thereafter.
• Screen thyroid function: assess TSH and free T4 at baseline and regularly during treatment.
• Assess infection status: avoid initiating therapy in the presence of active infection and postpone live vaccines.
• Contraindications: do not use in patients with known hypersensitivity to alemtuzumab or its excipients.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake the infusion solution.

Lemtrada may interact with other agents that affect immune function or hemostasis.

Major Interactions (Avoid)

• Live vaccines: administration can cause severe infection due to immunosuppression.
• Concurrent use of other potent immunosuppressants (e.g., high‑dose steroids, cyclophosphamide) may markedly increase infection risk.

Moderate Interactions (Monitor Closely)

• Non‑live vaccines: efficacy may be reduced; timing should be coordinated with the treating neurologist.
• Anticoagulants: monitor coagulation parameters as thrombocytopenia can alter bleeding risk.
• Antiviral prophylaxis agents: adjust dosing if significant cytopenias develop.