Clinical–MRI correlations in the secondary progressive phase of MS: lessons from the treatment trials

This figure plots on the same picture T2 lesion volume percentage change on annual MRI examinations in two interferon beta trials in SP MS . In the European SP trial [4], each annually comparison between IFN beta-1b and placebo groups are significant (p<0.0001). In SPECTRIM, differences between placebo and both doses of interferon beta-1a are significant beginning 6 months after the start of treatment (p<0.0001). No comparison was performed between the two trials. They are presented in the same picture to confirm the results in a similar range.

This figure shows the mean cumulative number of active lesions—i.e. new or enlarging lesions (T1 Gd-enhancing and new PD/T2 lesions) observed annually in the IFN beta-1b study cohort [4]. MRI scan at entry is a baseline. A significant reduction in the number of new or enlarging lesions in the interferon beta-1b group at annual time point compared with baseline was observed (p<0.0001).

This figure shows the median-combined unique active lesion per patient per scan—a parameter taking into account for T1 Gd-enhancing and active PD/T2 lesions without double-counting in the IFN beta-1a study [6]. This number was reduced by 78% for 22 μg and 89% for 44 μg compared with placebo (p=0.005 and p<0.0001) with a difference between doses (p=0.009).

This figure shows on the same picture the mean exacerbation/person/per year in two interferon beta trials in SP-MS . Mean annual relapse rate was reduced by about 30% in the treatment group compared to placebo in interferon beta-1b study (p=0.002). A reduction in a similar range was observed in the interferon beta-1a study (22 μg versus placebo=RR=0.69 {0.56–0.84} p<0.001; 44 μg versus placebo=RR=0.69 {0.56–0.85} p<0.001).

This figure shows median percentage change in hypointense T1 lesion load from baseline in the IFN beta-1b trial [12]. If a linear increase is observed in lesion load across time in both arms, the rate of increase is significantly slower in the interferon beta-1b-treated patients compared to placebo patients (p=0.0003).

This figure shows mean percentage change in cerebral volume compared with baseline for all patients in the IFN beta-1b trial over the study duration [19]. A mean reduction of 3.86% was observed by M36 in the placebo group compared to baseline, and a reduction of 2.91% in the interferon beta-1b-treated patients compared to baseline. There was no significant effect of treatment (p=0.14).