Assessing the Effect of Natalizumab of Magnetic Resonance Imaging Measures of Blood Brain Barrier Permeability and Myelin Integrity
Phase: PHASE4
Conditions: Multiple Sclerosis
Sponsor: Vanderbilt University Medical Center

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Protocol Version #: 3 
Protocol Date: May 11, 2021 
 
 
 
 
 
Natalizumab and Chronic Inflammation 
NCT05177718 
 
 
 
 
 
 
 
 
 
 
 
Francesca Bagnato, M.D., Ph.D. 
Assistant Professor of Clinical Neurology 
Head Neuroimaging Unit 
Neuro-Immunology Division 
Department of Neurology 
Vanderbilt University Medical Center 

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Protocol Version #: 3 
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Table of Contents 
Background 
…….Page 3 
Rationale and Specific Aims 
…….Page 4 
Animal Studies and Previous Human Studies 
…….Page 5 
Inclusion/Exclusion Criteria 
…….Page 5 
Enrollment/Randomization 
…….Page 6 
Study Procedures 
…….Page 7 
Risks 
…….Page 8 
Reporting of Adverse Events or Unanticipated Problems 
Involving Risk to Participants or Others 
…….Page 8 
Study Withdrawal/Discontinuation 
…….Page 9 
Statistical Considerations 
…….Page 9 
Privacy/Confidentiality Issues 
…….Page 9 
Follow-up and Record Retention ............................................................... Page 10 
References .................................................................................................. Page 10 
List of Attachments .................................................................................... Page 11 

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Background 
• The Importance of the Problem to be Addressed 
Multiple sclerosis (MS) is a chronic inflammatory-neurodegenerative disease of the 
central nervous system (CNS), affecting about 900,000 patients in the United States [1]. 
The disease starts with a relapsing remitting (RR) course followed by a secondary 
progressive phase in about 70% of patients. About 10% of MS patients have a primary 
progressive course. RRMS is characterized by the periodic occurrence of neurological 
symptoms or clinical flares [2]. Disease flare ups are due to the presence of inflammatory 
lesions sustained by the breakdown of the blood brain barrier (BBB) [3] and associated 
with variable degrees of demyelination and axonal injury. Upon the resolution of the 
BBB, some of these lesions undergo repair, whilst many persist as focal areas of 
demyelination and axonal damage, potentially leaving permanent functional impairment 
[4]. 
As the disease advances (or by the time of its onset in primary progressive MS patients), 
the inflammatory events no longer occur but patients progress into a relentless 
neurological decline. This decline is thought to be sustained by chronic demyelination 
which in its turn fosters neurodegeneration. Axons cannot survive chronic demyelination 
which ultimately leads them to death. The mechanisms inducing and sustaining chronic 
demyelination are largely known. Studies from histopathology indicate that there is 
always chronic inflammation where chronic demyelination occurs [5]. This chronic 
inflammation hinders repair and is trapped within what appears to be a subtly impaired 
BBB. Subtle changes in BBB permeability have been identified both postmortem [6] and 
in vivo [7] and, when present, predict future disease activity and progression [8,9]. 
Magnetic resonance imaging (MRI) assists with the diagnosis and monitoring of MS 
patients. Active lesions are visible on Tl-weighted (Tl-w) post-gadolinium MRI as hyper- 
intense contrast-enhancing lesions (CELs). The identification of CELs has revolutionized 
the diagnosis and treatment of MS [10]. A multitude of clinical trials evaluating drugs' 
efficacy in reducing CELs are continuously conducted and have led to the 
armamentarium of disease modifying agents (DMAs) available to treat patients with 
RRMS today [11]. Conversely, although established MRI surrogates of subtle BBB 
breakdown and demyelination are available, these are not routinely used as measures of 
outcome both in clinical trials and practice. 
Incorporating measures of BBB and myelin integrity in clinical studies will reduce 
uncertainty on the role of available medications as neuroprotective agents and disease 
control, beyond the resolution of overt inflammation. 
 
• Our Proposed Solution: Studying the Effect of Natalizumab on Chronic 
Inflammation and Demyelination 
The 21st century is facing the presence of a multitude of DMAs to treat patients with 
MS [11]. While each of these DMAs is sustained by different mechanisms of actions, all 
act in preventing overt BBB breakdown and inflammation. None of these DMAs acts 
upon the actual resolution of the BBB. 

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Thus, after the resolution of CEL, subtle leakages of the BBB may persist and continue to 
favor T-lymphocytes trafficking through the CNS. This trafficking may foster a state of 
chronic inflammation ultimately responsible of chronic demyelination. 
Natalizumab (Tysabri®) is a humanized monoclonal antibody against the a4 chain of 
integrins and acts as a selective adhesion molecule antagonist [12]. Opposite to other 
DMAs, due to its mechanisms of action, natalizumab is the only medication directly 
acting upon the BBB. By binding VLA-4 and inhibiting the translocation of activated 
VLA-4-expressing leukocytes across the BBB into the CNS, Natalizumab is the only 
DMA that can completely abolish the lymphocytic permeation. 
In the long term, this effect shall favor the resolution of chronic inflammation with the 
full restoration of the BBB integrity, a potential foster of remyelination and better quality 
of life (QoL), and certainly an obstacle to chronic demyelination. Thus, studying the 
effect of Natalizumab on BBB permeability and demyelination has the potential to unveil 
neuroprotective properties of this medication, thus far uncovered. 
 
 
Rationale and Specific Aims 
This is an open-label, prospective study. Natalizumab will be dosed according to the 
FDA approved label. We propose to apply dynamic contrast enhanced (DCE) and 
selective inversion recovery quantitative magnetization transfer imaging (SIR-qMT) in a 
cohort of patients with RRMS to assess the effect of Natalizumab on BBB and myelin 
integrity; and on QoL as measured using the electronic visual analog scales (EVAS). If 
the electronic version of the VAS is not available, paper copy will be provided to the 
participant. 
 
The short-term goal of our study is to demonstrate the ability of Natalizumab to 
decrease lesional and non lesional DCE-derived ktrans and preserve stable SIR-qMT 
derived macromolecular to free pool size ratio (PSR) values over a time period of 12 
months. 
The long-term goal of our line of inquiry is to discover hidden mechanisms of actions 
and neuroprotective properties of currently available DMA. 
The central hypothesis of our study is that Natalizumab fosters the restoration of the 
BBB integrity as early as three months after the first infusion and that this restoration 
ultimately 1) preserves myelin integrity and 2) favors improvement of QoL. We plan to 
prove our hypothesis through the following complementary aims. 
• Aim 1: To establish that DCE metric ktrans decreases with treatment. 
We hypothesize that ktrans differs between baseline (pre- treatment) and both 3 and 12 
months’ post-treatment as a result of better BBB restoration operated by natalizumab. 
• Aim 2: To establish that qMTI metric PSR increases with treatment. 
We hypothesize that upon a significant early (3 months post treatment) increase in PSR 
due to decrease in BBB permeability and subtle leakages operated by natalizumab, PSR 
will maintain stable levels over time secondary to myelin integrity preservation. 
• Aim 3: To explore changes in quality of life (QoL) operated by natalizumab. 
We hypothesize that natalizumab improves QoL as measured using the electronic visual 
analog scales (EVAS) or VAS, via the restoration of the BBB and that such an effect 

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correlates with drug serum level. 
• Additional Secondary Explorative Endpoints: 
1. Associations between QoL measures and ktrans values. 
2. Associations between ktrans and PSR values 
 
 
Animal Studies and Previous Human Studies 
In recent years, the use of DCE MRJ has emerged as a tool for probing BBB integrity 
in vivo [7-9]. DCE estimates hemodynamic parameters (e.g., cerebral blood flow, 
cerebral blood volume, and mean transit time) during the passage of the paramagnetic 
contrast agent gadolinium. In addition, it assesses vascular integrity by acquiring high 
spatial resolution Tl-w images before and after gadolinium injection. For 
intact BBB, gadolinium is too large to move into the tissue. However, when the BBB is 
compromised, the contrast agent will move into the tissue, shorten the surrounding tissue 
water Tl and increase the MRJ signal on a Tl-w scan. In addition to providing a 
qualitative description of the spatial location of BBB breakdown, it is possible to quantify 
kinetic parameters, such as Ktrans (ml/l00g/min). Ktrans provides a measure of the efflux 
rate of the gadolinium contrast from blood plasma into tissue and is an of subtle changes 
in the BBB [8,9]. 
Our work and that of others [14-18] proved that indices derived from qMT are solid 
predictors of myelin contents in brains of MS patients. By employing a two-pool model 
of magnetization transfer exchange between bound macromolecules (like myelin) and 
unbound pools (free water), qMT quantifies characteristics of single pools. This feature 
distinguishes it from the commonly used magnetization transfer ratio in that qMT is more 
specific to myelin content and less sensitive to non-biological scanner-related factors, 
which are not possible to be separated from edema using the standard magnetization 
transfer ratio measurements. We optimized a SIR-qMT protocol at 16 inversion times 
both a 3.0 Tesla (3T) [17,18] and 7T [14,15]. 
SIR-qMT is based on a biexponential model of inversion recovery data and its derived 
metrics are not influenced by the assumption of the macromolecular pool line shape such 
as in other quantitative magnetization transfer methods. The derived measure relevant to 
the studies I propose include PSR, reflective of the (%) quantity of pool of free molecules 
not bound to macromolecules. Upon validation of the sequence with bovine serum 
albumin phantoms [19] and animals with the experiential model of MS [20], we proved 
that SIR-qMT generates reproducible results between scans and that regional differences 
in PSR and RI fare also in accordance with the well-known biological differences in 
myelin content between white matter and grev matter tissues in both healthy subjects and 
MS patients as well as between lesional and non-lesional tissue in patients [17, 18]. 
 
Inclusion/Exclusion Criteria 
• Inclusion Criteria: 
1. Adult (age 18+) RRMS per McDonald Criteria (Attachment-1) 
2. Eligible to receive Natalizumab treatment 
3. Creatinine levels within normal range within 42 days (6 weeks) of MRI 

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• Exclusion Criteria: 
1. Pregnancy or breastfeeding 
2. Known sensitivity/allergy to MRI contrast 
3. Steroid treatment (oral or intravenous) within past 30 days 
 
 
Enrollment/Randomization 
Enrollment will occur at the Vanderbilt Comprehensive MS Center; no specific ethnic 
groups will be targeted or excluded from the study. Thirty-six (36) patients will be 
identified and enrolled by the study team. This studywill not require randomization. 
This study will receive review and approval from the Vanderbilt Human Research 
Protection Program (HRPP) prior to enrollment of any participants. 
There will be recruitment advertisements (Attachment-2A,2B) posted or provided 
in the VUMC MS clinic, where potential recruitment can happen. Patients 
visiting the VUMC hospital or MS clinic will be informed of the study by their 
hospital or clinic personnel, inclusive of nurses and physicians, or can inquire 
based on the presence of the flyer. If interested, patients will be notified by the 
research team for screening and subsequent informed consent. By nature, the 
subject demographic will mimic that of the pathologies examined found in the 
MidSouth region. 
Additionally, potential research subjects will be identified based on data available 
in the VUMC clinical system (e.g. Epic/eStar). Based on the list of upcoming 
appointments in the relevant clinics, patients’ Epic record will be reviewed for the 
specified inclusion/exclusion criteria. If the patient is deemed a candidate for the 
study, the study personnel will notify the patient’s care provider who will then 
ask the patient if they would be interested in communicating with study personnel 
about the research study. 
Subjects interested in participating in clinical research will be screened using the 
MRI screening form (Attachment-3). Informed consent will be obtained in a 
private setting (e.g., an otherwise empty conference room or waiting area) by one 
of the study Investigators. 
Each subject will also be able to complete the MRI screening form online, from 
her/his own home using the REDCAP software at the subjects’ computer. All 
data transmitted within REDCAP is secure with password-protected access. Prior 
to the study start, any of the associate investigators will take care of explaining 
the details of the study to the subject. The subject will receive a copy of the 
signed informed consent document. The study PI will be available to meet and/or 
talk in person with any of the subject shall any questions arise. 
The patient will be made aware that if they choose not to participate in the study, 
their care will not be altered in any way. It is possible that the person obtaining 
consent will have an existing relationship with the participant (e.g., he or she may 
be a colleague or coworker). Only peers or persons who do not work directly with 
a potential participant will obtain consent. The treating neurologist may also 
obtain consent. The potential participant will be told that agreement or refusal to 
participate will in no way affect his/her job or academic standing. 

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Protocol Version #: 3 
Protocol Date: May 11, 2021 
 
Study Procedures 
 
Procedures 
Baseline 
(M0) 
Month 3 
(M3) 
Month 12 
(M12) 
Obtain Informed Consent 
x 
Review of McDonald Criteria for RRMS 
x 
Concomitant Medication Review 
x 
x 
x 
Inclusion/Exclusion Review 
x 
Adverse Event/SAE Review specific to MRI 
x 
x 
x 
QoL measurement with EVAS/Visual Analog 
Scale 
x 
x 
x 
Pre-infusion Blood draw for future analyses 
x 
x 
x 
Creatinine level present on chart prior to MRI 
x 
x 
x 
Urine pregnancy test prior to MRI1 
x 
x 
x 
MRI with/without contrast2 
x 
x 
x 
Standard clinical assessments 
x 
x 
x 
1. For females of child-bearing potential 
2. MRI at M0 should occur immediately prior to start of 1st dose of Natalizumab. 
M3 and M12 MRIs should occur on same date ± 5 days as Natalizumab dose 
• Baseline: 
The baseline visit will last approximately 4 hours. This will include the following 
tests/procedures: 
1. Review, sign Informed Consent 
2. Inclusion/Exclusion Review 
3. Medical History, including MS history 
4. Concomitant medication review, including history of steroids within past 30 days 
5. Urine pregnancy test for females of child-bearing potential 
6. Creatinine level results on chart within past 42 days and within normal limits 
7. MRI with and without contrast (to occur prior to first dose of Natalizumab) 
8. Standard of care clinical assessments 
9. Blood sample obtained when IV line is placed for contrast MRI 
 
• Month 3 (M3) and Month 12 (M12): 
M3 and M12 visits will last approximately 4 hours each. The visit will include the 
following tests/procedures: 
1. Concomitant medication review 
2. Urine pregnancy test for females of child-bearing potential 
3. Confirm creatinine level results on chart within past 42 days 
4. MRI with and without contrast immediately prior to, or following, infusion 
5. Standard of care clinical assessments 
6. Adverse event review for MRI only 
7. QoL measurement utilizing the EVAS or VAS 
8. Blood sample obtained when IV line is placed for contrast MRI 

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• MRI 
MRI will be obtained at the Vanderbilt University Institute of Imaging Science. 
Participants will have IV inserted at the Vanderbilt MS Clinic prior to MRI. The 
participant will be accompanied to MRI facility by MS Research staff member. 
• Visual Analog Scale 
Assessment of quality of life will be completed at each time pint. The scale will be 
administered electronically (I-Pad) in the clinic by the research staff. 
• Routine Laboratory Assessments 
Urine pregnancy test will be performed on all females of child-bearing potential. This test 
will be paid for by research. 
Serum Creatinine results will be on file within 42 days of MRI. Serum creatinine will be 
obtained, and results reviewed prior to MRI. 
Blood Draw will occur at each time point when IV line is placed for contrast MRI. The 
research team will process and freeze specimens. Specimens will not be sent to the 
sponsor at this time. 
• Adverse Events 
Adverse events related to MRI procedure will be collected and reported. The Investigator 
will review all MRI-associated adverse events. 
 
 
Risks 
Potential risks related to MRI include: 
1. No major risks are associated with MRI 
2. Certain metal objects like watches, credit cards, hairpins, writing pens, etc. 
may be damaged by the machine or may be pulled away from the body during 
the scan. 
3. Hammering and clicking noise will occur throughout the scan 
4. Claustrophobia may occur 
5. Allergic reaction to the IV dye may occur 
6. Placing needle in arm for dye may cause pain and bruising 
 
Reporting of Adverse Events or Unanticipated Problems 
Involving Risk to Participants or Others 
Adverse events related to MRI will be collected on an ongoing basis. Adverse events will 
be reported promptly to the investigator for review and causality. Serious adverse events 
will be reported to Vanderbilt Human Research Protections Program within 24 hours of 
notification to site. Participants safety will be reviewed on an ongoing basis. 
Non-serious adverse events will be reported to HRPP during annual review. 

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Study Withdrawal/Discontinuation 
Participants may withdraw from the study at any time. 
Participants may be withdrawn from the study for the following reasons: 
1. Study discontinued by PI 
2. Pregnancy 
3. Discontinuation of Natalizumab 
4. Lost to follow-up 
 
Statistical Considerations 
• Power Analysis 
The sample size is enumerated on the basis of aim 1. Cramer and co-authors observed 
that the minimally detectable difference in DCE-derived metric k-trans was between 
NAWM of patients and that of healthy controls [7]. 
On the basis of their study number, and assuming that differences in normal appearing 
white matter BBB permeability between baseline and M12 will be of the same magnitude 
of that observed between patients and healthy controls in Cramer's study, a cohort of 30 
patients will be sufficient to detect such a difference (i.e. 0.05) with a power of 80% and 
a Type I Error alpha of 5%. A total of 36 subjects will be screened/enrolled for an 
anticipated dropout rate of 15%. 
• Statistical Plan 
Baseline clinical, demographical and MRI patients’ characteristics will be reported as 
mean±standard deviation and median (range) for continuous variables, and as frequency 
and percentage for categorical variables. 
Multivariable analyses will be used to compare group differences in absolute values and 
over-time changes of Ktrans and PSR. 
Ktrans values collected during the follow-up (i.e. M0, M3 and M12) will be analyzed 
using a longitudinal linear model, adjusted for potential confounders, using a spatial 
power covariance matrix to account for unequally spaced time visits. Within this model, 
using appropriate contrasts, we will assess: 
1. The mean change over the whole follow-up time of Ktrans 
2. The mean change between M0 and M3 
3. The mean change between M0 and M12 
The same statistical framework will be used to assed temporal change of PSR and QoL 
measurements. 
 
 
Privacy/Confidentiality Issues 
Participants will be enrolled and assigned a unique ID number, along with initials. Blood 
samples will be stored in -20 freezer at the Vanderbilt Comprehensive MS Center for 
future analyses of immune correlates and Natalizumab serum levels. The specimens will 
be de-identified prior to storage. Only the research team will have the codes to identify 

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participants. 
 
Follow-up and Record Retention 
Records and documents pertaining to the conduct of this study will be retained by the 
Principal Investigator for 5 years after completion of study. 
 
 
 
References 
1. Wallin MT et al. The prevalence of MS in the United States: A population-based 
estimate using health claims data. Neurology 2019;92:e1029-e1040 
2. Reich DS et al. Multiple sclerosis. N Engl J Med 2018; 378-169-80. 
3. McFarland H, et al. Using gadolinium-enhanced magnetic resonance imaging 
lesions to monitor disease activity in multiple sclerosis. Ann Neurol. 1992; 
32:758-66. 
4. Kutzelnigg A, et al. Cortical demyelination and diffuse white matter injury in 
multiple sclerosis. Brain. 2005;128:2705-12. 
5. Patrikios P, et al. Remyelination is extensive in a subset of multiple sclerosis 
patients. Brain. 2006;129:3165–72. Erratum in Brain. 2007;130:879. 
6. Vos CM, et al. Blood-brain barrier alterations in both focal and diffuse 
abnormalities on postmortem MRI in multiple sclerosis. Neurobiol Dis. 2005; 20: 
953-60. 
7. Tofts PS. Modeling tracer kinetics in dynamic Gd-DTPA MR imaging. J Magn 
Reson Imaging. 1997;7: 91-101. 
8. Cramer SP, et al. Abnormal blood-brain barrier permeability in normal appearing 
white matter in multiple sclerosis investigated by MRI. Neuroimage Clin. 2013; 
4: 182-9. 
9. Cramer SP, et al. Permeability of the blood-brain barrier predicts conversion from 
optic neuritis to multiple sclerosis. Brain. 2015; 138: 2571-83. 
10. Katz D, et al. Correlation between magnetic resonance imaging findings and 
lesion development in chronic, active multiple sclerosis. Ann 
Neurol.1993;34:661-9. 
11. Bagnato F, et al. Newer agents in the treatment of multiple sclerosis. Neurologist. 
2015; 19:104-17. 
12. Shirani A, et al. Natalizumab for Multiple Sclerosis: A Case in Point for the 
Impact of Translational Neuroimmunology. J. Immunol. 2017; 198: 1381-6 
13. Kos D, et al. Electronic visual analogue scales for pain, fatigue, anxiety 
and quality of life in people with multiple sclerosis using smartphone and tablet: a 
reliability and feasibility study. Clin Rehab 2017;31:1215-25. 
14. Dortch RD, et al. Quantitative magnetization transfer imaging of human brain at 7 
T. Neuroimage 2013; 64: 640-9. 
15. Bagnato F, et al. Selective Inversion Recovery Quantitative Magnetization 
Transfer Brain MRI at 7T: Clinical and Postmortem Validation in Multiple 
Sclerosis. J Neuroimaging. 2018; 28: 380-8 

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16. Schmierer K, et al. Magnetization transfer ratio and myelin in postmortem 
multiple sclerosis brain. Ann Neurol 2004; 56: 407-15. 
17. Dortch RD, et al. Quantitative magnetization transfer imaging of human brain at 
3T via selective inversion recovery. Magn Reson Med. 2011; 65: 1346-3. 
18. Bagnato F, et al. Selective inversion recovery quantitative magnetization transfer 
imaging: Toward a 3 T clinical application in multiple sclerosis. Mult Scler. 2019 
Mar 25:1352458519833018. doi: 10.1177/1352458519833018. [Epub ahead of 
print] 
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inversion recovery sequence. Magn Reson Med. 2003; 49: 501-5. 
20. Janve VA, et al. The radial diffusivity and magnetization transfer pool size ratio 
are sensitive markers for demyelination in a rat model of type III multiple 
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criteria. Lancet Neurol. 2018;17:163-73. 
 
 
List of Attachments 
 
McDonald criteria_2017 
Attachment-1 
Study Advertisement Flyer 
Attachment-2A-B 
MRI Screening Form 
Attachment-3