Related Experiment Video
Updated: Mar 25, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Extended interval dosing of natalizumab in multiple sclerosis
L Zhovtis Ryerson1, T C Frohman2, J Foley3
1Department of Neurology, Langone Medical Center, New York University, New York, New York, USA.
Extending natalizumab (NTZ) infusion intervals up to 8 weeks and 5 days maintained treatment effectiveness for multiple sclerosis (MS). This extended interval dosing (EID) approach showed no significant decrease in efficacy and did not result in any cases of progressive multifocal leukoencephalopathy (PML).
Area of Science:
- Neurology
- Immunology
- Pharmacology
Background:
- Natalizumab (NTZ) is an effective therapy for multiple sclerosis (MS).
- NTZ carries a risk of progressive multifocal leukoencephalopathy (PML).
- Extended interval dosing (EID) is being explored to potentially reduce PML risk.
Purpose of the Study:
- To evaluate the clinical consequences of reducing NTZ infusion frequency up to 8 weeks and 5 days.
- To assess the effectiveness and safety of EID regimens compared to standard interval dosing (SID).
Main Methods:
- Retrospective chart review across 9 MS centers.
- Patients stratified into standard interval dosing (SID; every 4 weeks) and extended interval dosing (EID) groups (early, late, or variable).
- EID groups included early (4w3d–6w6d), late (7w–8w5d), and variable schedules.
Main Results:
- EID showed a trend towards fewer new T2 lesions (14% vs 17%) and no significant difference in enhancing T1 lesions (9% vs 7%) compared to SID.
- Annualized relapse rate was lower in the EID group (0.09) versus SID (0.14).
- No PML cases were observed in the EID group, compared to 4 cases in the SID cohort.
Conclusions:
- Extending NTZ infusion intervals up to 8 weeks and 5 days did not diminish treatment effectiveness.
- EID appears to maintain clinical and radiographic disease control in MS patients.
- Further monitoring is needed to confirm if EID reduces PML risk.
More Related Videos
04:45Lumbar Intrathecal Injection of SOD1-ASOs for Precise CNS Targeting and Predictive Efficacy in Human SOD1-G93A ALS Mice
Published on: February 24, 2026
08:18A Protocol for the Use of Remotely-Supervised Transcranial Direct Current Stimulation tDCS in Multiple Sclerosis MS
Published on: December 26, 2015
Related Concept Videos
Drug Accumulation During Multiple Dosing: Intermittent IV Infusions
Drug Accumulation During Multiple Dosing: Repetitive IV Injections
Dosage Regimens: Partial Pharmacokinetic Parameters
Dosage Regimen: Fixed Dose
Fixed-dose regimens can be used for various routes of administration, including intravenous (IV) injections and oral medications. For IV administration, a predetermined amount of the drug is...
Dosage Regimen: Multiple Oral Dosage
Dosage Interval and Administration Route: Determination Methods