Class:  Monoclonal antibodies, anti-CD52

Name: Alemtuzumab (Lemtrada®)

Frequency: 5 days of IV infusion year 1 and 3 days IV infusion year 2.

Mechanism of Action: Kills all cells expressing CD52 including B cells. Changes regulation of immune system.

Effectiveness: Compared to interferon, reduces relapses by over 50%, and MRI lesions by over 80%. Decreases brain atrophy 40%.

Possible Side Effects: Boxed warning* for serious (sometimes fatal) autoimmune conditions which occur in up to 40% such as immune thrombocytopenic purpura which is a bleeding disorder, life-threatening infusion reactions, heightened risk of malignancies. Infusion reactions (92%), rash (53%), lymphopenia (99.9%). Only available through REMS**. Approved by FDA for rescue use only.

Alemtuzumab, formerly called Campath but now known as Lemtrada, is an approved leukemia treatment (used for chronic lymphocytic leukemia (CLL), cutaneous T-cell lymphoma (CTCL) and T-cell lymphoma). Alemtuzumab is an antibody that significantly decreases the levels of multiple immune cells by binding to specific proteins on immune cells. In 2008, early tests at Cambridge University suggested that alemtuzumab might be useful in treating and even reversing the effects of MS. In June 2012, the makers of Lemtrada, Genzyme Corp., applied to the FDA and the European Medicines Agency (EMA) for approval of the therapy.

In 2011, Genzyme Corp. presented five-year follow-up data from its completed Phase II MS trial that continued to show durable reductions in relapse rate and sustained accumulation of disability four years after the majority of patients received their last course of the investigational compound alemtuzumab. The Phase II trial compared alemtuzumab to Rebif (interferon beta-1a) in early RRMS patients who had received no prior therapy. In the trial, alemtuzumab was given to patients in two or three annual cycles of not more than five days per cycle, while Rebif was given to patients three-times per week, every week for three years.

The five-year analysis of early RRMS patients from the trial found that patients taking once-yearly cycles of alemtuzumab reduced their risk of relapse by 72% and the risk of sustained accumulation of disability by 73% compared to patients treated with the active comparator Rebif. Further, the annualized relapse rate and disability risk measured from year three to four remained at the same low level observed in prior years of the study.

Study side effects included certain autoimmune diseases, such as thyroid disorders—seen in 25% of study participants—viral infections, and a serious blood-clotting disorder (idiopathic thrombocytopenic purpura, ITP). As a result, those who are treated with alemtuzumab must be monitored closely for these conditions.

Video recorded in 2015. Dr. Timothy Vollmer retired as Medical Director of the Rocky Mountain MS Center in 2021. 

* Boxed Warning: A black boxed warning is the FDA’s most stringent warning for drugs and medical devices on the market. Black box warnings, or boxed warnings, alert the public and health care providers to serious side effects, such as injury or death.

** REMS (Risk Evaluation and Mitigation Strategy): REMS is a drug safety program that the U.S. Food and Drug Administration (FDA) can require for certain medications with serious safety concerns to help ensure the benefits of the medication outweigh its risks.