Natalizumab for the Treatment of People With Inflammatory Demyelination Suggestive of Multiple Sclerosis, or Definite Multiple Sclerosis, at First Presentation (AttackMS) (AttackMS)

January 5, 2026 updated by: Queen Mary University of London

AttackMS: Natalizumab for the Treatment of People With Inflammatory Demyelination Suggestive of Multiple Sclerosis, or Definite Multiple Sclerosis, at First Presentation

Multiple Sclerosis (MS) is a chronic inflammatory & degenerative disease of the central nervous system (CNS) Recent data from the MS Base registry demonstrated an average delay of 152 - 215 days between first presentation and the diagnosis of MS, and more than one year until Disease Modifying Treatment (DMT) begins.

Evidence suggests that shutting down inflammation using highly effective DMTs early after diagnosis leads to better long term clinical outcomes The AttackMS trial will test the effect of starting a highly-effective DMT licensed for MS, Tyruko® (Natalizumab 300mg), within a short time - 14 days - after symptom onset.

Study Overview

Detailed Description

MS is a disease of the central nervous system affecting over 130,000 people in the UK and more than 2.8 million worldwide. Left untreated, MS leads to chronic disability in the large majority of cases.

CIS is a common first manifestation of MS: There is a more than 80% chance of MS in somebody presenting with CIS provided one or more "lesions" characteristic of inflammatory demyelination can be detected on a magnetic resonance imaging (MRI) of the brain. The presence of at least two such lesions is an inclusion criterion for this study. Inflammatory demyelination is the process by which cells of your body's own immune system attack the insulation sheath (= myelin) of nerve fibres (= axons) in the central nervous system.

Once a diagnosis of MS has been confirmed, many people with this disease will be eligible for what is called "disease-modifying treatment" (DMT) on the NHS. Such treatment targets the immune cells that are involved in the inflammatory attack against the myelin sheaths and nerve fibres. However, while in a small number of cases, a diagnosis of MS can be made instantaneously it regularly takes week, months and, sometimes even longer, to fulfil the formal diagnostic criteria of MS. This diagnostic delay inevitably leads to delays in starting disease-modifying treatment.

Using a trial concept geared towards rapid assessment of eligibility, and a disease-modifying treatment that is both highly effective and generally well tolerated in people with MS, AttackMS will test whether:

(i) It is feasible to recruit participants with a diagnosis of CIS at high risk of MS, or definite MS, at first presentation for treatment within 14 days of symptom onset and (ii) Such early treatment improves myelin repair at 3 months, as measured using a special MRI technology called magnetisation transfer ratio (MTR).

Natalizumab (Tyruko®) is a medication currently approved by the Medicines and Healthcare products Regulatory Agency (MHRA) as a disease-modifying treatment for adults with rapidly evolving severe (RES) relapsing MS. We are looking to test safety and efficacy of treatment with Tyruko® 300mg, given through a needle in a vein (intravenous infusion), over 20 weeks and to advance mechanistic understanding in treating people with first presentation of CIS or MS.

AttackMS will test the effect of starting a highly-effective DMT licensed for MS, Tyruko®, within a short time - 14 days - after symptom onset. The main objective is to test Tyruko®, given intravenously every 4 weeks over 20 weeks, for safety, efficacy, and to advance the mechanistic understanding of the earliest events in inflammatory demyelination/MS.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Participant has provided informed consent.
  2. Age 18-55 years
  3. Participant with CIS or MS at first presentation.
  4. Participants show two or more lesions on T2 weighted MRI suggestive of demyelination.
  5. Participant is willing and able to comply with clinical visits and procedures outlined in the study protocol.

Exclusion Criteria:

  1. Hypersensitivity to Tyruko® or to any of the following excipients:

    • Histidine
    • Histidine monohydrochloride
    • Sodium chloride
    • Polysorbate 80 (E433)
    • Water for injections
  2. Evidence of multiple chronic demyelinating lesions on MRI without signs of recent activity.
  3. Participants with increased risk for opportunistic infections, including immunocompromised participants (those currently receiving immunosuppressive therapies or those immunocompromised by prior therapies).
  4. Combination with other Disease Modifying Treatments..
  5. Known active malignancies, except for participants with cutaneous basal cell carcinoma.
  6. Implants such as pacemaker, aneurysm clip in the brain and MRI-incompatible prosthetic heart valves.
  7. Significant comorbidities such as cardiac failure, renal failure, uncontrolled diabetes and uncontrolled hypercholesterolemia.
  8. History of stroke, thrombosis and/or myocardial infarction.
  9. Any other infection deemed, in the assessment of the PI or sub-investigator, clinically significant.
  10. Claustrophobia
  11. Pregnancy or breastfeeding

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Tyruko® 300mg
Tyruko® 300mg, administered via intravenous infusion in a 4 week cycle, for a total of 6 cycles
Tyruko® is indicated as single disease modifying therapy in adults with highly active relapsing remitting multiple sclerosis. Tyruko® 300mg concentrate for solution for infusion and matching placebo are collectively referred to as IMP when detailing to blinded trial procedures. Tyruko® 300mg will be colourless, clear to slightly opalescent solution.
Other Names:
  • Natalizumab
Placebo Comparator: Placebo
Placebo, administered via intravenous infusion in a 4 week cycle, for 3 cycles, followed by Tyruko® 300mg, administered via intravenous infusion for a total of 3 cycles
Placebo is colourless, clear to slightly opalescent liquid. The formulation of the is the same as that of commercial Tyruko® minus the active ingredient. Placebo is in the same containers/vials as Tyruko®.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
To establish whether there is efficacy superiority of Natalizumab (Tyruko®) over placebo at 12 weeks in facilitating remyelination of previously demyelinated CNS lesions, as measured by MRI lesion magnetization transfer ratio (MTR).
Time Frame: 12 weeks
Mean magnetisation transfer ratio (MTR) change in FLAIR-hyper-intense lesions at 12 weeks compared to baseline
12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
To establish whether there is a difference between participants receiving Natalizumab (Tyruko®) or placebo at 24 weeks in P100 latency measured using visually evoked potentials (VEP).
Time Frame: 0 and 24 weeks
P100 latency in each eye at week 24 compared to baseline. Inter-ocular P100 latency difference at week 24 compared to baseline.
0 and 24 weeks
To establish whether there is a difference between participants receiving Natalizumab (Tyruko®) or placebo at 24 weeks in number and occurrence of adverse events.
Time Frame: 24 weeks
24 weeks
To establish whether there is a difference between participants receiving Natalizumab (Tyruko®) or placebo at 24 weeks in facilitating remyelination of previously demyelinated CNS lesions using Magnetisation transfer ratio (MTR).
Time Frame: 0, 12 and/or 24 weeks
0, 12 and/or 24 weeks
To establish whether there is a difference between participants receiving Natalizumab (Tyruko®) or placebo at 24 weeks in protecting limb function.
Time Frame: 24 weeks

Serum-neurofilament light chain levels (SNfL) at week 24 compared to baseline. Expanded Disability Status Scale (EDSS) at week 24 compared to baseline. SDMT (Symbol Digit Modalities Test) score at week 24 compared to baseline. Lower Limb Function: The T25-FW (Timed 25 Foot Walk) will be collected in all pwMS. able to walk the required distance at week 24 compared to baseline.

9-HPT (Nine Hole Peg Test) at week 24 compared to baseline. NFI-MS (Neurological Fatigue Index-MS) score at week 24 compared to baseline 24 weeks.

24 weeks
To establish whether there is a difference between participants receiving Natalizumab (Tyruko®) or placebo at 24 weeks in Retinal nerve fibre layer ganglion cell + inner plexiform (GCIP) layer thickness measured using optical coherence tomography (OCT).
Time Frame: O and 24 weeks
O and 24 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Klaus Schmierer, Queen Mary University of London
  • Principal Investigator: Liqun Zhang, St George's University Hospital NHS Foundation Trusts
  • Principal Investigator: Victoria Singh-Curry, Chelsea and Westminster Hospital Foundation Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 1, 2022

Primary Completion (Estimated)

October 31, 2027

Study Completion (Estimated)

October 31, 2027

Study Registration Dates

First Submitted

February 17, 2022

First Submitted That Met QC Criteria

June 10, 2022

First Posted (Actual)

June 14, 2022

Study Record Updates

Last Update Posted (Estimated)

January 7, 2026

Last Update Submitted That Met QC Criteria

January 5, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

IPD data collected on the trial will be uploaded to the Pragmatic Clinical Trials Unit Safehaven and linked using pseudoanonymised participant IDs. Any further sharing of participant data to other researchers will be fully anonymised as specified at the time of participant consent.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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