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Clinical trial Recruiting at 1 site Phase 2 Interventional Ages 18 to 55

Early natalizumab treatment for people with first signs of MS

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

Run by Queen Mary University of London · NCT05418010 · Data updated 2026-11-12

This trial will try giving natalizumab within 14 days of symptom onset to adults with a first presentation of MS or clinically isolated demyelination to see if very early treatment reduces inflammation and early disease activity.

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Quick facts

PhasePhase 2
Study typeInterventional
Ages18 Years to 55 Years
SexAll
Enrollment40 (estimated)
SponsorQueen Mary University of London
Academic / other
Drugs / interventionsNatalizumab
Locations2 sites (London and 1 other locations)
StatusRecruiting
StartedDecember 1, 2022
Main results expectedOctober 31, 2027
Study endsOctober 31, 2027
Registry record updatedJanuary 7, 2026
Trial IDNCT05418010 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults 18–55 with a first presentation of CIS or MS who have two or more T2 lesions on MRI, can start treatment within 14 days of symptom onset, and are willing to attend study visits are ideal candidates.

Probably not a fit

People with inactive chronic lesions without recent activity, those who are immunocompromised or on other disease-modifying therapies, or those with hypersensitivity to natalizumab or its excipients are unlikely to benefit or be eligible.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

AttackMS is a Phase 2, randomized interventional trial enrolling adults aged 18–55 who present with clinically isolated syndrome or first-presentation MS and show two or more T2 lesions on brain MRI. Participants are randomized to receive natalizumab (Tyruko 300 mg) or placebo started within 14 days of symptom onset and followed with scheduled clinical visits. Outcomes include MRI measures, blood biomarkers such as neurofilament light chain, and clinical assessments to track inflammatory activity and safety. The design aims to shorten the usual diagnostic and treatment delays and test whether immediate high-efficacy therapy limits early CNS damage.

Why it matters

Potential benefit: If successful, very early natalizumab could reduce early inflammatory damage and lower the risk of early relapse or disability progression.

How similar studies have gone: Natalizumab is an established high-efficacy MS therapy and early use of high-efficacy DMTs has been associated with better outcomes, but randomized trials of starting natalizumab within days of first symptoms are relatively novel.

Who can join: the full rules

Show full inclusion / exclusion criteria 
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

Where it's running

  • St George's Hospital
    London, United Kingdom     Recruiting
  • Royal London Hospital
    London, United Kingdom     Not yet recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
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Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.