How does it work?

Rituximab is a drug which depletes a type of immune cells called B cells, which may play a role in the immune attack on the on the brain and spinal cord tissues in MS. It is approved for use with certain types of lymphoma and a form of arthritis. 

How is it administered?

Rituximab is given via two infusions into the blood stream two weeks apart. 

To what type of MS is it targeted?

Relapsing remitting MS.
It is also currently being tested in primary progressive MS
 

Most recent trial details

One study was primarily to determine the safety and tolerability of rituximab and also to asses the effects on relapse rate and disease activity observed on MRI brain scans. The trial involved giving 26 people with relapsing remitting MS two infusions of rituximab two weeks apart, and then another dose six months later. The number of active lesions detected by MRI, were reduced from week 4 to week 48. The number of relapses was also significantly reduced.

A phase II study of Rituximab in 104 people with relapsing remitting MS showed a reduction in the total number of lesions observed on serial MRI brain scans over 24 weeks compared to placebo. The number of active lesions was reduced by 90 per cent in the group taking rituximab compared to the people taking the placebo, and fewer people taking rituximab had relapses.
 

Current situation

Genentech are currently running a phase II/III, study in the US and Canada to evaluate the safety and effectiveness of rituximab in people with primary progressive MS. The study aims to enrol approximately 435 participants. Results are due out in 2009. (ClinicalTrials.gov Identifier: NCT00087529) 

Side effects

The drug has been associated with severe side effects such as fatal injection reactions and progressive multifocal leukencephalopathy, though these have not occurred in the MS studies. The most common adverse events observed in people treated with Rituximab were infusion reactions and infections.