A Study of Oxidative Pathways in MS Fatigue

1Background 1.1 Multiple Sclerosis Multiple sclerosis is the most common cause of
non-traumatic disability in young adults in the US. It is an inflammatory, demyelinating and
neurodegenerative disease of the central nervous system. Patients with MS often experience
various types of disabling symptoms such as chronic fatigue or pain. Most patients with an
initial relapsing-remitting course develop at some point insidious disability worsening, i.e.
secondary progressive MS. In contrast, about 15% of multiple sclerosis patients experience an
insidiously progressive course from onset. Primary and secondary progressive multiple
sclerosis is thought to have similar physiopathology. As such, strategies for managing
symptoms of relapsing patients may not necessarily apply to those with progressive disease;
however, most symptomatic treatment trials have been done in relapsing-remitting or mixed
populations of patients, neglecting a large fraction of patients with progressive forms of
the disease. Investigator is planning to address an important clinical and pathophysiologic
issue in this proposed study.

1.2 Fatigue in multiple sclerosis Fatigue as defined by a subjective lack of physical or
mental energy perceived by the individual with usual activities is the most common and
disabling symptom of multiple sclerosis. Fatigue severity is not correlated with depression
or neurological disability. It can impact substantially physical and cognitive activities and
thus, negatively affect the quality of life of many patients. There are no medications
specifically approved for fatigue in multiple sclerosis. Many chronic inflammatory disorders
are associated with fatigue and peripheral inflammation is postulated to be an important
contributor to fatigue pathogenesis. A spectroscopy study has reported decreased
N-acetylaspartate/creatine ratio in several brain regions, thus all pointing at axonal loss
as a possible contributing factor . In a cross-sectional relapsing-remitting MS study,
fatigued patients had more severe atrophy of the striatum, thalamus and frontal and parietal
gyri as compared to non-fatigued patients.

As a direct consequence of the unknown pathophysiology, very little pharmacologic
intervention is available for fatigue in multiple sclerosis. Glutamate, a critical
neurotransmitter implicated in excitotoxicity and neurodegeneration, may also play a role in
fatigue genesis. Two studies of a glutamate receptor antagonist (memantine) have reported
worsening of fatigue in multiple sclerosis patients. In addition, Investigator have found
that compared to placebo, riluzole (a medication with some anti-glutamate activity) worsened
fatigue in patients with very early multiple sclerosis. This is in sharp contrast with the
pathological evidence suggesting that excessive glutamate transmission may be a final
effector in neuronal and axonal degeneration in multiple sclerosis animal models. Oxidative
stress due to disequilibrium between oxidants and antioxidants in the central nervous system
may also be a major contributor to neurodegeneration . It is unknown if oxidative stress
plays a role in the pathogenesis of fatigue in multiple sclerosis.

1.3 Fatigue rating scales Most of the fatigue scales used in multiple sclerosis studies were
primarily developed and validated for use in other medical conditions. The two widely used
self-completed scales in multiple sclerosis research are the Fatigue Severity Scale, and the
Modified Fatigue Impact Scale.

1.3a. Fatigue Severity Scale: This scale was originally designed to identify the common
features of fatigue in multiple sclerosis, and lupus patients. It assesses the impact of
fatigue on several outcomes, with an emphasis on physical fatigue. It is composed of 9
questions with responses provided on a 7-point Likert scale. Scale score is the mean of the
item scores and higher scores indicate more severe fatigue.

1.3b.Modified Fatigue Impact Scale: This scale has been proposed by the Multiple Sclerosis
Council for Clinical Practice Guidelines as the instrument of choice for assessing fatigue in
multiple sclerosis. It is derived from the 40-item Fatigue Impact Scale. It has 21 items and
assesses more dimensions of fatigue than the Fatigue Severity Scale: physical (9 items),
cognitive (10 items) and psychosocial (2 items). The scale score is the sum of the 21 items
and higher score indicates more severe fatigue. The scale has shown good reproducibility,
ease of use and good correlation with fatigue severity scale scores. A cut-off value of 38
distinguishes fatigued from non-fatigued multiple sclerosis patients.

2.Rationale 2.1 Effect of N-acetyl cysteine in MS fatigue N-acetyl cysteine is an orally
bioavailable precursor of the amino acid cysteine and is used to treat acetaminophen-induced
hepatotoxicity. The medication half-life in adults is about 5.6 hours. As such it has been
given twice or three times a day in various trials that have documented a biological effect.
It protects the liver by restoring hepatic concentrations of cysteine and glutathione (GSH- a
major intracellular antioxidant). Besides antioxidant properties, N-acetyl cysteine, by
increasing the intracellular concentration of cysteine and activating the glutamate-cysteine
antiporter eventually decreases glutamatergic transmission. Hypothetically, by decreasing
excitotoxicity, it may protect neurons in different models of neuronal damage and
neurodegeneration. Excellent safety profile and potential neuroprotective properties make
N-acetyl cysteine an attractive target for examining its anti-fatigue properties in patients
with progressive multiple sclerosis. Orally administered N-acetyl cysteine produces
biologically relevant cerebrospinal fluid concentrations of N-acetyl cysteine at doses that
are well tolerated. One study showed an effect of a single injection of N-acetyl cysteine on
blood glutathione redox ratios followed by changes in glutathione concentration in the brain
using 7T magnetic resonance spectroscopy in 3 patients with Parkinson's disease and 3
controls.

Clinical trials of oral N-acetyl cysteine for a wide variety of clinical conditions have used
a range of different daily doses (from 600 mg to 6000 mg per day). The study investigator
chose the daily dose of 3750 mg (1250 mg administered three times a day), based on its good
tolerability, treatment compliance and minimum adverse effects reported in a recent clinical
trial.

2.2 Reason for using a placebo group

There are no FDA-approved treatments for fatigue in multiple sclerosis. There are also no
standard of care as various trials have reported inconsistent findings about the effect of
amantadine in multiple sclerosis fatigue. Pursuant to the Helsinki Declaration, when standard
treatment of a disease exists, placebo should generally not be used in clinical trials.
However, Declaration of Helsinki supports the stance that placebo can be acceptable in the
setting where no proven standard therapy exists:

The benefits, risks, burdens and effectiveness of a new intervention must be tested against
those of the best current proven intervention, except in the following circumstances:

- The use of placebo, or no treatment, is acceptable in studies where no current proven
intervention exists; or

- Where for compelling and scientifically sound methodological reasons the use of placebo
is necessary to determine the efficacy or safety of an intervention and the patients who
receive placebo or no treatment will not be subject to any risk of serious or
irreversible harm.

2.3 Gap in fatigue management Symptomatic treatment trials for fatigue have been small,
underpowered and with methodological flaws. As such, drawing firm conclusions and making
therapeutic recommendations has been difficult. Thus, fatigue in multiple sclerosis remains
very difficult to manage despite its substantial impact on patients' life. An issue when
studying fatigue in patients with relapsing-remitting multiple sclerosis has been the
possibility of increased fatigue during disease relapses and with specific disease-modifying
therapies such as interferon. There has been no study focusing on the effects of drug therapy
in fatigue in patients with progressive disease. Furthermore, study investigator's knowledge
regarding the underlying pathophysiology of fatigue in multiple sclerosis is scarce and
future studies of intervention on fatigue should include biomarkers to further elucidate the
potential mechanisms of observed effects.

The study investigator hypothesize that fatigue in progressive multiple sclerosis patients is
associated with increased glutamate and decreased glutathione concentration on brain
spectroscopy at baseline. The study investigator also hypothesize that fatigue is associated
with changes of various oxidative pathway metabolites in peripheral blood.

4. Study Design 4.1 Overview of study design: This is a 4-week randomized,
placebo-controlled, parallel group, double-blind, single center trial on effect of N-acetyl
cysteine versus placebo on fatigue in patients with progressive multiple sclerosis defined by
McDonald criteria. Subjects, who enter the treatment phase of study, will be randomly
assigned to either N-acetyl cysteine (1250mg 3 times a day or placebo ( three times a day)for
4 weeks.There will be 3 in-person study visits (screening, baseline, and week 4 and 2 visits
over the phone (week 2, and week 6 which is 2 weeks after completing last study drug dose).
Visits will all occur in the morning to maximize consistency of assessments and evaluate main
outcomes within 2hours of morning dose of study medication. Questionnaires, and research
samples will be obtained before neurological exam or magnetic resonance imaging. Research
blood draws will be obtained just after questionnaire completion. Brain spectroscopy will be
obtained less than 2hours after morning dose of study drug to maximize detection of the
biological effect of study medication.

4.2 Enrollment sites Enrollment will start in August, 2016. Enrollment period will last 6
months. Patients will be enrolled in the trial at University of California San Francisco.

4.3 Study visits 4.3a Screening period: Total duration of screening period is 4 weeks. An
additional 5 patients with progressive multiple sclerosis who volunteered for participation
in the clinical trial, but had a screening modified fatigue impact scale score of <38 or were
recruited from site's clinic (who reported no fatigue and their fatigue scale score was <38),
will undergo brain imaging on 7Tesla magnetic resonance imaging machine, and research blood
draws.

4.3b Treatment period: Total duration of the blinded treatment period is 4 weeks. After the
screening visit, the inclusion/ exclusion criteria details of eligible patients will be
reviewed by study investigator. The eligible study participants will be randomized in
approximately a 2:1 ratio to one of the two arms of either N-acetyl cysteine or placebo. The
treatment group assignment will be blinded for the duration of the study. A week-2 phone
visit will be completed to determine the tolerance of study drug.

4.3c Follow up phone visit: Two weeks after taking the last dose of study medication, fatigue
scale questionnaires are completed over phone by the study coordinator to collect the safety
and efficacy measures of the study. Additional phone visit needs to be completed 2 weeks from
randomization to assess the safety, tolerability, and compliance of study medication.

4.5 Study visit window: The screening period can be up to 4 weeks. The baseline visits needs
to be completed within 28 days of screening visit. Week 2 phone visit in +/- 5 days of Day
14, and week 4visit in Day 28+/-7 days of baseline. Follow-up phone call is completed +/- 5
days of week 6 visit.

Inclusion Criteria:

1. Age 18 through 75 years included.

2. Ability to sign the informed consent before participation.

3. Females of childbearing age must have a negative pregnancy test at screening and use
an effective method of contraception during the study participation period.

4. Diagnosis of primary or secondary progressive multiple sclerosis (according to the
2010 McDonald criteria).

5. Time since first reported MS symptoms more than one year.

6. EDSS score at the time of screening 2.0-6.5.

7. Fatigue reportedly present and screening MFIS more than 38 for patients who will be
enrolled in the randomized placebo controlled part of the study. MFIS score of less
than 38 is required for patients who are controls on the study.

Exclusion Criteria:

1. History of MS relapses in the previous 3 months.

2. Neurodegenerative progressive neurological disorders other than progressive MS.

3. Breastfeeding

4. History of bleeding disorders

5. Abnormal results of liver function test at screening (AST or ALT more than twice the
upper limit of normal).

6. Receiving or about to start interferon beta or immunosuppressive medications (e.g.
cyclophosphamide, mitoxantrone, methotrexate, mycophenolate mofetil) as these
medication can be associated with fatigue.

7. Starting or changing the dose of other MS disease-modifying medications (including
monoclonal antibodies such as rituximab, ocrelizumab, alemtuzumab, daclizumab) within
3 months of baseline visit.

8. No ongoing steroid treatment and no steroid treatment in the prior month.

9. Inability to undergo MRI scans (e.g. weight>350 pounds, severe claustrophobia, metal
in the body).

10. Medical terminal conditions.

11. Currently treated for active malignancy or metastatic malignancy that has been treated
in the past 1 year or undergoing extra screening for recurrence

12. Planned surgery within the following 12 weeks

13. Planning to move with the following next 12 weeks

14. Participating in another clinical trial with an experimental medication.

15. Alcohol or substance abuse, or any other condition that in the investigator's opinion
would make the patient unsuitable for this study.

16. A history of allergic or anaphylactic reaction to NAC, or any component of the
preparation.

17. Clinically unstable medical or psychiatric disorders that require acute treatment.

18. Active gastrointestinal ulcers.

19. Subjects taking concomitant medications or supplements known for their glutamatergic
effects (e.g., dextromethorphan, D-cycloserine, memantine, lamotrigine, riluzole),
antioxidant properties (DMG, TMG, other alternative treatments), or medications with
an effect on sleepiness and possibly fatigue such as Provigil, Nuvigil and amantadine
within 2 weeks of the baseline visit with the exception of short-term use of
dextromethorphan as needed as a cough suppressant. Regular multivitamins will be
allowed.

20. Patients taking anticoagulants

21. Patients with history of obvious secondary causes of fatigue, such as chronic
insomnia, sleep apnea, narcolepsy, restless leg syndrome and significant bladder
dysfunction disrupting sleep.

22. Screening Epworth Sleepiness Scale score greater than 15.

23. Starting or changing the dose of benzodiazepine, antidepressant, antipsychotics,
anti-histamines, or stimulants within a month from the screening visit.

24. A score of 15 or greater on the Hospital Anxiety and Depression Scale (HADS)
depression subscale.

25. Patients currently treated for asthma.