Multiple Sclerosis Drug Triggers Severe Adverse Events

The multiple sclerosis (MS) drug alemtuzumab causes severe and unpredictable adverse events (AEs).

Alemtuzumab is a therapeutic antibody that attaches to the CD52 protein found on the surface of T and B lymphocytes, and results in the depletion of almost all lymphocytes. Since its approval, it is known that a quarter of patients treated with alemtuzumab display mostly minor AEs, called secondary autoimmune processes.

In 2 case reports published in a correspondence in Lancet Neurology, 2 patients with highly-active MS were infused with alemtuzumab. Despite multiple prior treatments, the patients suffered from severe illness relapses with inflammation in the central nervous system. After 6 months of treatment with alemtuzumab, the symptoms worsened significantly.

Using an MRI, the authors discovered a kind of new inflammation mode, where vast areas in the brain had numerous ring-enhancing lesions, according to the report. This pattern was not displayed in the patients’ previous medical history.

It is unclear if the AEs increased MS activity or whether it was the result of an independent secondary autoimmune process, the authors noted.

The scientists were able to successful curb the AEs by performing a blood plasma exchange, and then treating the patients with rituximab. The results of the treatment showed the ring-shaped deposits receded in both of the patients’ brains. Furthermore, after 1 year of treatment, the patients remained stable.

“This therapeutic algorithm could help MS patients around the world who develop similar [adverse events] under alemtuzumab,” concluded lead author Dr Aiden Haghikia.

The authors believe the immunocytes are to blame for the AEs. They hope the measures they used could benefit patients who develop similar AEs from alemtuzumab.