Washout Period Following Dimethyl Fumarate Treatment Cessation Associated with MS Disease Activity and Relapse
According to results presented at the 24th Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC), disease activity was significantly associated with the duration of the interval between cessation of dimethyl fumarate (DMF) treatment and the initiation of an alternative disease-modifying therapy (DMT) in people with relapsing remitting multiple sclerosis (RRMS).
Researchers evaluated DMF-DMT interval (defined as time in years between stopping DMF and beginning another DMT) based on DMF-treated patient demographics and disease activity data acquired via retrospective chart review. Disease activity was assessed according to clinical relapse or lesions in the brain or spinal cord identified via MRI. Statistical analyses were conducted to identify relationships between DMF-DMT interval, disease activity, and ALC.
- Disease activity was present during the DMFDMT interval in 28.7% of the 87 patients included in the analysis.
- DMFDMT interval duration was significantly associated with disease activity (odds ratio [OR], 10.97 [3.04 to 39.6]; P=.0003).
- Following DMF treatment cessation, patients were 11.09 times more likely to experience relapse or disease activity for each year spent without treatment.
- There was a median time to relapse of .47 years for individuals assessed in the study.
- For patients who experienced a clinical relapse during the DMFDMT interval, clinical relapse rates were higher after DMF treatment cessation compared to those before DMF initiation (P=.034)
- Though absolute lymphocyte count (ALC) decreased significantly after cessation of DMF (P=.0001), there was no association identified between ALC, disease activity, and DMFDMT interval duration.
According to the study authors, the findings suggest that earlier initiation of an alternate DMT after DMF treatment cessation may help to prevent risk of relapse, increased lesion burden, and potential disability accruement.