Alemtuzumab

What it is and how it works

Mechanism of Action The precise mechanism by which alemtuzumab exerts its therapeutic effects in multiple sclerosis is unknown but is presumed to involve binding to CD52, a cell surface antigen present on T and B lymphocytes, and on natural killer cells, monocytes, and macrophages. Following cell surface binding to T and B lymphocytes, alemtuzumab results in antibody-dependent cellular cytolysis and complement-mediated lysis.

Mechanism class: CD52-directed Antibody Interactions

Indications

is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include relapsing-remitting disease and active secondary progressive disease, in adults. Because of its safety profile, the use of LEMTRADA should generally be reserved for patients who have had an inadequate response to two or more drugs indicated for the treatment of MS . LEMTRADA is a CD52-directed cytolytic monoclonal antibody indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include relapsing-remitting disease and active secondary progressive disease, in adults. Because of its safety profile, the use of LEMTRADA should generally be reserved for patients who have had an inadequate response to two or more drugs indicated for the treatment of MS. Limitations of Use : LEMTRADA is not recommended for use in patients with clinically isolated syndrome (CIS) because of its safety profile. Limitations of Use LEMTRADA is not recommended for use in patients with clinically isolated syndrome (CIS) because of its safety profile .

Dosage and administration (summary)

Baseline laboratory tests are required prior to treatment. Administer LEMTRADA by intravenous infusion over 4 hours for 2 or more treatment courses: Initial treatment of 2 courses: First course: 12 mg/day on 5 consecutive days. Second course: 12 mg/day on 3 consecutive days 12 months after first treatment course. Subsequent treatment courses of 12 mg per day on 3 consecutive days (36 mg total dose) may be administered, as needed, at least 12 months after the last dose of any prior treatment course. Premedicate with corticosteroids prior to LEMTRADA infusion for the first 3 days of each treatment course.

Contraindications

is contraindicated in patients: with known hypersensitivity or anaphylactic reactions to alemtuzumab or any of the excipients in LEMTRADA who are infected with human immunodeficiency virus (HIV) because LEMTRADA causes prolonged reductions of CD4+ lymphocyte counts with active infection Known hypersensitivity or anaphylactic reactions to alemtuzumab or any of the excipients in LEMTRADA Infection with Human Immunodeficiency Virus Active infection

Warnings and precautions

Immune Thrombocytopenia: Obtain complete blood counts (CBCs) with differential prior to initiation of treatment and at monthly intervals thereafter until 48 months after the last infusion. Glomerular Nephropathies: Obtain serum creatinine levels, urinalysis with cell counts and urine protein to creatinine ratio prior to initiation of treatment. Monitor serum creatinine levels and urinalysis with cell counts at monthly intervals thereafter until 48 months after the last infusion.

Pregnancy

Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of LEMTRADA in pregnant women. LEMTRADA was embryolethal in pregnant huCD52 transgenic mice when administered during organogenesis . Auto-antibodies may develop after administration of LEMTRADA.

Storage and supply

Storage and Handling Store LEMTRADA vials at 2°C to 8°C (36°F to 46°F). Do not freeze or shake. Store in original carton to protect from light.

Source: Alemtuzumab (Lemtrada) — US FDA prescribing information, 2025-11-03, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.