Natalizumab wearing-off symptoms: Patients with MS on extended interval dosing may not "mind the gap"

No evidence of fluctuations in daily step count between infusions in people with multiple sclerosis treated with anti-CD20 monoclonal antibodies

Background

Patients with multiple sclerosis (MS) on some disease-modifying therapies (i.e., natalizumab), report a "wearing-off" effect characterized by increased symptoms directly before infusions. Prior research suggests this may reflect natural MS fluctuations rather than true treatment waning; however, this has not been confirmed for anti-CD20 agents (e.g., ocrelizumab). Daily step count (STEPS) can reflect overall function. This study examined temporal associations between anti-CD20 therapy infusions and STEPS.

Methods

Retrospective analysis evaluated data from two Fitbit-monitored cohorts (N = 145 total, 32 anti-CD20-treated participants) across 60 treatment cycles. Monthly STEPS were recorded directly pre- and three-month post-infusion over the six-month treatment intervals. Mixed-effects models evaluated the relationship between infusion timing, STEPS, and participant demographics, controlling for confounding variables.

Results

No significant difference in STEPS was observed pre- versus post-infusion (p = 0.32). An average decrease of 3.3% was noted post-infusion but was not statistically significant. No associations between STEPS and participant characteristics (e.g., age, disability level) were identified. Individual variability existed, but no clear group-level trends emerged.

Conclusions

This study found no evidence of an association between timing of anti-CD20 infusion and changes in STEPS. Findings highlight the need for integrating objective measures with patient-reported outcomes and biomarkers in future research to better understand potential treatment fluctuations.

Improvement of fatigue, depression, and processing speed two weeks post Natalizumab infusion in Multiple Sclerosis: No difference between standard and extended interval dosing schedules

BACKGROUND

Fatigue, depression and slow processing speed are debilitating symptoms in people with Relapsing-Remitting Multiple Sclerosis (RRMS) that significantly impacts on the quality of life. Natalizumab, a disease-modifying treatment, improves clinical symptoms but questions remain about the comparative efficacy between its standard interval dosing (SID) and extended interval dosing (EID) schedules.

OBJECTIVE

To examine the impact of short term natalizumab dosing schedules-SID versus EID-on the so called "invisible symptoms", specifically focusing on symptom exacerbation during the 'wearing-off' phase before infusion and the subsequent relief post-infusion.

METHODS

Forty-two RRMS patients were assessed one week before (T0) and two weeks after pre-and post-natalizumab infusion (T1) for fatigue symptoms using the Fatigue Scale for Motor and Cognitive Functions (FSMC), the Modified Fatigue Impact Scale (MFIS), and the Fatigue Symptoms and Impacts Questionnaire-Relapsing Multiple Sclerosis (FSIQ-RMS). Processing speed and depression were measured by the symbol digit modality test (SDMT), and the Beck Depression Inventory-II (BDI-II). Participants were categorized into either the SID or EID dosing schedules of natalizumab, and their outcomes were compared.

RESULTS

Forty-two patients (21 SID; 21 EID) completed the study. Fatigue severity scales, SDMT, and BDI-II scores improved from T0 to T1. No significant differences in fatigue symptoms were found between the SID and EID groups, whether during the "wearing-off" period (T0) or post-infusion (T1).

CONCLUSIONS

Both SID and EID dosing regimens of natalizumab are similarly effective in reducing fatigue symptoms, depression and improving processing speed in individuals with RRMS, with no observed differences during the "wearing-off" periods or after re-infusion.

Insight into motor fatigue mechanisms in natalizumab treated multiple sclerosis patients with wearing off

Motor fatigue in Multiple Sclerosis (MS) is due to reduced motor cortex (M1) output and altered sensorimotor network (SMN) modulation. Natalizumab, a disease-modifying therapy, reduces neuroinflammation and improves fatigue. However, some patients treated with natalizumab experience fatigue recurrence ('wearing-off') before subsequent infusions. Wearing-off provides a valuable window into MS-related motor fatigue mechanisms in a controlled, clinically stable, setting. This study investigates whether wearing-off is associated with worsening motor fatigue and its neurophysiological mechanisms and assesses natalizumab's effect on MS-related fatigue. Forty-five relapsing-remitting MS patients with wearing-off symptoms were evaluated pre- and post-natalizumab infusion. Assessments included evaluating disability levels, depressive symptoms, and the impact of fatigue symptoms on cognitive, physical, and psychosocial functioning. The motor fatigue index was computed through the number of blocks completed during a fatiguing task and peripheral, central, and supraspinal fatigue (M1 output) were evaluated by measuring the superimposed twitches evoked by peripheral nerve and transcranial magnetic stimulation of M1. Transcranial magnetic stimulation-electroencephalography assessed M1 effective connectivity by measuring TMS-evoked potentials (TEPs) within the SMN before- and after the task. We found that wearing-off was associated with increased motor fatigue index, increased central and supraspinal fatigue, and diminished task-related modulation of TEPs compared to post-natalizumab infusion. Wearing-off was also associated with worsened fatigue impact and depression symptom scores. We conclude that the wearing-off phenomenon is associated with worsening motor fatigue due to altered M1 output and modulation of the SMN. Motor fatigue in MS may reflect reversible, inflammation-related changes in the SMN that natalizumab can modulate. Our findings apply primarily to MS patients receiving natalizumab, emphasizing the need for further research on other treatments with wearing-off.

Effects of disease-modifying therapy on peripheral leukocytes in patients with multiple sclerosis

Modern disease-modifying therapies (DMTs) in multiple sclerosis (MS) have variable modes of action and selectively suppress or modulate the immune system. In this review, we summarize the predicted and intended as well as unwanted adverse effects on leukocytes in peripheral blood as a result of treatment with DMTs for MS. We link changes in laboratory tests to the possible therapeutic risks that include secondary autoimmunity, infections, and impaired response to vaccinations. Profound knowledge of the intended effects on leukocyte counts, in particular lymphocytes, explained by the mode of action, and adverse effects which may require additional laboratory and clinical vigilance or even drug discontinuation, is needed when prescribing DMTs to treat patients with MS.