Does MRI lesion activity regress in secondary progressive multiple sclerosis?

Area of Science:

• Neuroscience
• Radiology
• Clinical Trials

Background:

• Contrast-enhancing lesions (CELs) on MRI scans indicate active inflammation in multiple sclerosis (MS).
• A previous study showed decreasing CEL rates in relapsing-remitting MS (RRMS) patients over 9 months.

Purpose of the Study:

• To investigate the trend of new CELs in placebo-treated secondary progressive MS (SPMS) patients.
• To determine if the phenomenon observed in RRMS patients applies to SPMS patients.

Main Methods:

• Analysis of monthly MRI scans from two cohorts of placebo-treated SPMS patients (Cohort-1: 9 months, Cohort-2: 6 months).
• Categorization of patients based on initial CEL count (0, 1-3, >3) and history of pre-study relapses.
• Examination of monthly new CEL rates across different subgroups.

Main Results:

• Cohort-1 showed no significant change in monthly new CEL rates, irrespective of initial CEL levels.
• Cohort-2 exhibited a 33% decrease in monthly new CEL rates from months 1-3 to 4-6 in patients with 1-3 or >3 initial CELs.
• A decreasing CEL rate was observed in a small subgroup (12 patients) with >3 initial CELs and pre-study relapses across combined cohorts.

Conclusions:

• The short-term trend of new CEL activity in placebo-treated SPMS patients is variable and may differ between patient cohorts.
• Initial lesion load and relapse history might influence the observed CEL activity trends in SPMS.