Switch to Ofatumumab and Level of Immunoglobulins (SOLI)

This real-life study aims to describe IgG levels after switching from ocrelizumab 600 mg IV every 6 to 8 months in Patients with Multiple Sclerosis (PwMS) to ofatumumab 20 mg SC every month and showing a decreasing level of IgG during treatment by ocrelizumab in real life practice in France over 24 months of follow-up.

The primary objective is therefore to determine if the downward trend of IgG observed during ocrelizumab treatment is modified after a switch to ofatumumab, in PwMS treated during at least 18 months of ocrelizumab in real life practice, over 24 months of follow-up.

Study Overview

• Status: Not yet recruiting
• Conditions: Multiple Sclerosis
• Intervention / Treatment: Drug: ofatumumab

Detailed Description

time perspective: retrospective and prospective

• Study Type: Observational
• Enrollment (Estimated): 115

Contacts and Locations

• Study Contact: Name: PATRICK VERMERSCH, Pr; Phone Number: 06.33.38.32.60; Email: patrick.vermersch@chu-lille.fr

Study Locations

• France
  • Lille, France, 59000
    • CHU de Lille
    • Contact: Patrick VERMERSCH, Dr; Phone Number: 06.33.38.32.60; Email: patrick.vermersch@chu-lille.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population will be adult patients with MS (women and men) who initiate treatment with ofatumumab after a treatment with ocrelizumab

Description

Inclusion Criteria:

1. Adult patients (≥ 18 years old) who had been treated with ocrelizumab for a relapsing form of Multiple Sclerosis according to the ocrelizumab marketing authorization (MA) treatment regimen for at least 18 months.
2. Patients with a decrease of IgG at a minimum of two consecutive dosages (around six months apart) during ocrelizumab treatment*.
3. Patients already switched or switching from ocrelizumab to ofatumumab treatment (decision independent from the study*).
4. Patients agreeing to participate to the study.

5. Able to provide their non-opposition

   • At the discretion of the investigator, if a benefit for patients is expected based on their experience and depending on patient's characteristics

Exclusion Criteria:

1. Patients with ocrelizumab dose spacing > 8 months in the last 18 months before switch
2. Patient who underwent an immunoglobulin supplementation therapy within 18 months before the switch
3. Ongoing or planned pregnancy

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Ofatumumab; Adult patients (≥18 years) with relapsing multiple sclerosis treated with ocrelizumab for at least 18 months and already switched or switching from ocrelizumab to ofatumumab treatment	Drug: ofatumumab; There is no treatment allocation. Participants with MS that initiated treatment with ofatumumab (Kesimpta ®) as per neurologist practice and regardless of the study protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Slope of serum immunoglobulin G (IgG) levels during ocrelizumab treatment period (minimum 18 months)	42 months
Slope of serum immunoglobulin G (IgG) levels during ofatumumab treatment period (24 months)	42 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Age at baseline (years)	Baseline
Number and percentage of patients with stable serum IgG levels	24 months
Number of severe infections occurring during ocrelizumab treatment period prior to switch to ofatumumab	18 months
Slope of serum immunoglobulin M (IgM) levels during ocrelizumab treatment period (minimum 18 months)	24 months
Distribution of Expanded Disability Status Scale (EDSS) scores after switch to ofatumumab	24 months
Number of patients who discontinued ofatumumab before the end of follow-up	24 months
Number and type of adverse events (AEs) during ofatumumab follow-up period	24 months
Disease duration (years since diagnosis)	Baseline
Sex distribution (male/female, %)	Baseline
Number and percentage of patients with increased serum IgG levels	24 months
Slope of serum immunoglobulin M (IgM) levels during ofatumumab treatment period (24 months)	24 months
Distribution of Fatigue Severity Scale (FSS) scores after switch to ofatumumab	24 months
Distribution of Multiple Sclerosis Functional Composite (MSFC) scores after switch to ofatumumab	24 months
Number of relapses per patient after switch to ofatumumab	24 months
Reasons for discontinuation of ofatumumab before the end of follow-up	24 months
Number and type of serious adverse events (SAEs) during ofatumumab follow-up period	24 months

Collaborators and Investigators

• Sponsor: University Hospital, Lille

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2029
• Study Completion (Estimated): June 1, 2029

Study Registration Dates

• First Submitted: May 15, 2026
• First Submitted That Met QC Criteria: May 28, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Multiple Sclerosis; Ofatumumab; Kesimpta; NIS; IgG; Ocrelizumab; IgM
• Additional Relevant MeSH Terms: Nervous System Diseases; Autoimmune Diseases; Immune System Diseases; Demyelinating Autoimmune Diseases, CNS; Autoimmune Diseases of the Nervous System; Demyelinating Diseases; Multiple Sclerosis; ofatumumab
• Other Study ID Numbers: 2024_0720; 2025-A02557-42 (Other Identifier: [ID-RCB number, ANSM])

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No