Interferon beta-1b 16-year long-term follow-up study: MRI outcomes


D. Li, G. Ebers, A. Traboulsee, R. Tam, D.S. Goodin, A. Konieczny for the Betaseron/Betaferon LTF Study Group and the UBC MS/MRI Research Group

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Background: The interferon beta-1b (IFNB-1b; Betaferon®) pivotal study demonstrated efficacy, safety and tolerability of IFNB-1b in patients with relapsing-remitting (RR) multiple sclerosis (MS), including a persistent beneficial effect on MRI lesion burden over 5 years.

The 16-year Long-term Follow-up (16-Year LTF) study is hypothesis generating, with the aim to assess the long-term treatment effects of IFNB-1b on clinical outcomes and relate these to changes in MRI outcomes.

Design/Methods: The 16-Year LTF is a multicentre, open-label, observational study utilising cross-sectional data collected from patients from all 11 centres who participated in the original pivotal trial. MRI scans were analysed at a single centre and MRI outcome measures assessed included T2 burden of disease (BOD), normalised brain volume (NBV), gadolinium-enhancing lesions, black holes and cervical cord area at C2 (CCA).

The results have been analysed by stratification according to the original treatment assignment of the pivotal trial (placebo, 50 mcg IFNB-1b subcutaneously [sc] every other day [eod], 250 mcg IFNB-1b sc eod) and also according to the length of exposure to treatment over the 16 years, i.e. “always” = IFNB-1b >80% of the time; “ever” = IFNB-1b >10–80% of the time; “never” = IFNB-1b <=10% of the time.

Results: 328 of the original 372 patients have been identified (i.e. 88.2%). 192 patients underwent MRI studies. Technically adequate C2 CCA data was available in 81 patients. A trend was observed between T2 BOD and increasing disability within the stratified groups. Furthermore, patients with a higher EDSS score tended to have a smaller NBV and reduced CCA. When SPMS status was used as a covariate with T2 BOD, a trend was observed, with less T2 BOD in the “always” group than the “never” group. Further analyses are currently being performed, and results will be presented at the meeting.

Conclusions: Although significant differences between the groups were not observed, preliminary results indicate that the changes in the different MRI measures over time in the whole cohort are in line with expected clinical progression. Moreover, covariates such as SPMS appear to be important when analysing these findings. Measurements of the cervical cord area at C2 provided results consistent with the brain measurements.