Lymphopenia in Human Patients Treated with Fumarate-based Therapies
In a study of 274 MS patients, 32.8% developed grade ≥2 lymphopenia during treatment with fumarate-based therapies. The average absolute lymphocyte count dropped by 46% from baseline. Factors such as older age at treatment initiation and co-administration of dalfampridine were linked to higher rates of lymphopenia. Among those affected, 61% recovered their lymphocyte counts after treatment stopped, with an average recovery time of 22 months.
- Tags
- #MSResearch
- Most relevant to
- —
- Human efficacy
- Not established from this source
- Mechanism
- Not reported
- Evidence strength
- Limited
- Outcome
- Positive
Why it matters
This research highlights the relatively high incidence of lymphopenia in patients treated with fumarates, exceeding previous estimates. Understanding these associations can inform monitoring practices during treatment.
What this does not prove
The findings stem from a retrospective chart review, which may be impacted by incomplete data or selection bias.
Next milestone
No next milestone was established from the available source.
Study facts
- Study design
- Observational
- Participants / samples
- 274 · basis not reported
- Randomised
- Not reported
- Controlled
- Not reported
- Primary endpoint met
- Not reported
- Relevant MS type
- Not reported
- Publication date
- 2026-10-27
- Evidence reviewed
- Abstract only
- Regulatory approval
- Not reported
- Research areas
- Not classified
- Biological target
- Not reported
- Pathway
- Not reported
- Population
- Not reported
- Size of effect
- Not reported
- Secondary endpoints
- Not reported
- MRI endpoints
- Not reported
- Biomarkers
- Not reported
- Safety
- Not reported
Original sources
- Primary evidenceFumarate-induced lymphopenia in multiple sclerosis: A retrospective analysis. ↗DOI: 10.1016/j.msard.2026.108021
Supporting passages (13)
study phaseLymphopenia is an expected side effect of fumarate-based multiple sclerosis (MS) disease modifying therapies.
study designMETHODS: This retrospective chart review evaluated incidence and severity of lymphopenia among 274 patients treated with fumarates and examined associations between fumarate-associated lymphopenia and clinical variables with univariate and multivariate analyses.
subjectsMETHODS: This retrospective chart review evaluated incidence and severity of lymphopenia among 274 patients treated with fumarates and examined associations between fumarate-associated lymphopenia and clinical variables with univariate and multivariate analyses.
sample sizeMETHODS: This retrospective chart review evaluated incidence and severity of lymphopenia among 274 patients treated with fumarates and examined associations between fumarate-associated lymphopenia and clinical variables with univariate and multivariate analyses.
peer reviewedJournal: Multiple sclerosis and related disorders
publication datePublication date: 2026-10-27
interventionPURPOSE: Lymphopenia is an expected side effect of fumarate-based multiple sclerosis (MS) disease modifying therapies.
primary endpointMETHODS: This retrospective chart review evaluated incidence and severity of lymphopenia among 274 patients treated with fumarates and examined associations between fumarate-associated lymphopenia and clinical variables with univariate and multivariate analyses.
follow upAmong those who developed grade ≥2 lymphopenia, ALC recovered to ≥1.0 K/mL in 61%, with average time of 22 months (SD 23) after treatment discontinuation.
findingsOlder age upon fumarate initiation was significantly associated with grade ≥2 lymphopenia (1.048 (95% CI=1.023, 1.074), p=0.0001).
outcomeIn this real-world clinical cohort, fumarate-associated lymphopenia incidence exceeds published estimates.
limitationsTitle: Fumarate-induced lymphopenia in multiple sclerosis: A retrospective analysis.
peer reviewedPublication types: Journal Article
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