Lemtrada (alemtuzumab) is FDA-approved for relapsing forms of multiple sclerosis. Because of its safety profile, Lemtrada should generally be reserved for patients who have had inadequate response to two or more other MS medications. Lemtrada is an antibody treatment that is given in the vein over 5 days the first year and 3 days the second year. Eighty percent of patients do not require treatment in the 3rd year. Lemtrada removes certain immune cells from the body for months (approximately 6 months for B lymphocytes and 1 year for T lymphocytes).
In the CARE-MS I Trial, 581 early, active relapsing-remitting patients, who had received no prior MS therapy, were randomized to Rebif or Lemtrada treatment. Compared to those MS patients on Rebif, those individuals on Lemtrada had 55% less relapses. A low percentage of patients had worsening disability on both treatments without a significant difference between Rebif and Lemtrada (11% and 8% respectively worsened). In the CARE-MS II Trial, Lemtrada IV treatment dropped new relapses by half (49%) compared to Rebif in a 2 year trial. People with MS treated with Lemtrada also were 42% less likely to progress in disability than on Rebif and have less MRI activity.
Autoimmune disease is a risk of Lemtrada including 34% thyroid disease (including 1% orbital involvement), 2% incidence of low platelets which can lead to serious bleeding complications (thrombocyopenia), and 0.3% serious renal disease (glomerular nephropathies). Other risks include serious infections (including fungal and herpetic) and serious infusion reactions including anaphylaxis. Lemtrada may cause an increase risk of malignancy include thyroid cancer, melanoma and lymphoproliferative disorders.
Safety monitoring includes baseline and monthly complete blood count with differential, serum creatinine and urinalysis with cell counts monthly for 4 years. At baseline and every 3 months, blood thyroid function testing (such as TSH) should be checked. In addition, patients need baseline and yearly skin exams to screen for melanoma.