Related Experiment Video
Updated: Aug 14, 2025

An Alternative and Validated Injection Method for Accessing the Subretinal Space via a Transcleral Posterior Approach
Published on: December 7, 2016
Decrease of natalizumab drug levels after switching from intravenous to subcutaneous administration in patients with
Alyssa A Toorop1, Zoé L E van Kempen2, Maurice Steenhuis3
1Department of Neurology, MS Center Amsterdam, Amsterdam UMC Location VUMC, Amsterdam, The Netherlands a.toorop@amsterdamumc.nl.
Background:
Natalizumab is effective in the treatment of multiple sclerosis (MS). In 2021, the European Medicines Agency approved the subcutaneous (SC) variant of natalizumab which can be used instead of intravenous administration. However, the course of drug levels varies between administration routes, and the Food and Drug Administration rejected the request for approval of natalizumab SC for reasons that were not disclosed. Our objective was to evaluate the course of natalizumab trough drug levels in patients who switched from natalizumab intravenous to SC on various treatment intervals.
Methods:
The NEXT-MS trial (N=382) investigates personalised treatment of natalizumab, in which infusion intervals are prolonged based on individual natalizumab trough drug levels. In 2021, an amendment was approved allowing participants to switch from intravenous to SC administration with frequent measurements of natalizumab drug levels and antidrug antibodies (ADAs). Results were compared with linear mixed model analyses.
Results:
Until December 2022, 15 participants switched to SC natalizumab. Natalizumab drug levels with SC administration were on average 55% lower compared with intravenous administration (Exp (estimate) 0.45, 95% CI 0.39 to 0.53, p<0.001), leading to very low trough drug levels in three patients on extended treatment intervals. No natalizumab ADAs were detected during intravenous or SC treatment. None of the participants on natalizumab SC showed evidence of MS disease activity.
Conclusions:
Natalizumab trough drug levels can decrease after switching from natalizumab intravenous to SC administration. We advise to monitor trough drug levels in patients with low natalizumab drug levels during intravenous treatment, patients with higher body mass index or patients on extended treatment intervals who switch to SC administration of natalizumab.
More Related Videos
16:56Sublingual Immunotherapy as an Alternative to Induce Protection Against Acute Respiratory Infections
Published on: August 30, 2014
09:38Determining Immune System Suppression versus CNS Protection for Pharmacological Interventions in Autoimmune Demyelination
Published on: September 12, 2016
Related Concept Videos
Nonlinear Pharmacokinetics: Drug Elimination for IV Bolus Injection
Following the administration of a single intravenous (IV) bolus injection, we can determine the concentration of the drug in the plasma at any given time. This calculation is achieved using a specific equation that integrates the values of Vmax and KM.
We can also...
Drug Delivery: Parenteral Route
There are three primary parenteral routes: intravenous (IV), intramuscular (IM), and subcutaneous (SC). The IV route introduces the drug directly into the bloodstream, ensuring immediate action. The IM route...
Desensitization and Tachyphylaxis
Routes of Drug Administration: Parenteral
The intravenous route (IV) of drug administration can be further categorized into two types. The bolus injection administers the entire dose rapidly, while an intravenous infusion slowly delivers smaller doses steadily.
The IV route is often...
Oral Hypoglycemic Agents: Glinides
Drugs for Treatment of Crohn's Disease in IBD Using Biologic Agents: Anti-TNF