Results of a study demonstrated that Natalizumab ( Tysabri ) promoted regeneration and stabilization of damage done to the myelin sheath, as measured by advanced MRI technology. Damage to the myelin sheath causes the symptoms of multiple sclerosis.

The imaging study included a total of 110 subjects.
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The effect of Natalizumab on lesions and NABT in relapsing multiple sclerosis was evaluated with a Voxel-Wise ( VW ) imaging method using magnetization transfer ratio ( MTR ).
VWMTR is recognized as a powerful instrument for monitoring disease activity and effectiveness of therapeutic interventions in patients with multiple sclerosis.

In the study, 62 patients who received Natalizumab were followed for 12 months together with 26 patients who received Interferon beta-1a ( Avonex ) IM and 22 age-matched and sex-matched normal controls.
For each subject, baseline and follow-up MTR volume maps were placed in a common halfway-space. The resulting VW subtraction map was then enhanced via threshold-free cluster enhancement ( TFCE ) algorithm, and a significance threshold was determined based on subject-specific Monte Carlo simulation. Supra-threshold volumes ( 95th percentile ) were quantified for both areas of increasing ( remyelinating ) and decreasing ( demyelinating ) MTR voxels, which represent a volume value.

There was no significant difference in decreasing VWMTR NABT volume over the follow-up between Natalizumab-treated and normal control groups.
Relapsing-remitting patients on both therapies showed higher remyelination potential and less evident demyelination than relapsing secondary progressive patients.
The volume of VWMTR changes in NABT ( decreasing or increasing ) was almost 3-5 times higher than the amount of changes observed for T2-lesion volume. This indicates that the VWMTR method might be a much more sensitive approach to capture demyelination / remyelination changes over time than the lesion-based volume measures.

Source: Biogen Idec, 2009

XagenaMedicine2009


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