Mesenchymal stromal cells for treatment of drug resistant pediatric Juvenile idiopathic arthritis

Juvenile Idiopathic Arthritis (JIA) is a frequent childhood disease with a
prevalence of 1 per 1000 children. Arthritis and related conditions, such as
JIA, cost the U.S. economy nearly $128 billion per year in medical care and
indirect expenses, including lost wages and productivity. Its presentation,
clinical course and response to treatment differ from its adult counter part
Rheumatoid Arthritis (RA). Severe forms such as Systemic JIA and polyarticular
JIA are associated with significant disability and loss of quality of life, as
well as numerous side effects from chronic immune suppression, including
corticosteroids. The introduction of the biological agents including blockers
of TNF alpha-receptor, IL-1receptor and IL-6receptor have greatly improved the
outcome. Annual costs of these biologics are around 11,000 Euro. However a
proportion of these children remains refractory to all of these very expensive
drugs. We were the first to show earlier that using another form of cellular
therapy, autologous SCT, was effective in some 50% of such children, even after
8 years of follow up. It was associated with complications caused by the
myeloablation and profound immunosuppression such as infections and fatal
haemophagocytosis.
Given the immunosuppressive effects of Mesenchymal Stromal Cells (MSC) and
clinical responses observed in animal models and the current human studies in
treatment of resistant graft versus host disease, diabetes, SLE and Rheumatoid
Arthritis, application of allogeneic MSC is an attractive and safe option and
may prove very relevant for this group with the poorest clinical outcome. As
stated above patients with treatment resistant JIA have a severe disability and
loss in quality of life and have often life long associated financial costs.
When effective, these young children retain their ability for schooling, work
and social activities. Application of MSC is quite simple compared to
haemopoietic stem cell transplantation. It can be performed as a short
inpatient procedure and does not require hazardous treatment with
myelo-ablative drugs. The current experience within the European Blood and
Marrow Transplantation Group (EBMT) of more than 700 patients with aGVHD after
allogeneic SCT show that allogeneic MSC infusion is safe. A systematic review
of 8 RCTs including 321 patients with ischemic stroke, Crohn*s disease,
cardiomyopathy, myocardial infarction, graft versus host disease, and healthy
volunteers receiving intravascular (both autologous and allogeneic) MSC did not
detect an association between acute infusional toxicity, organ systemic
complications, infection, death or malignancy. There was a significant
association between MSC and transient fever. Also in the 189 refractory RA
patients who received allogeneic MSC, most adverse events were mild and
transient (such as transient fever after infusion persisting for maximal 2
hours); there was only one patient who experienced a serious adverse event
leading to discontinuation of the treatment.
Administering MSC to more Rheumatoid Arthritis patients will however not teach
us more about the safety and efficacy in RF-negative JIA (>90% of all JIA)
since from a pathophysiologic, clinical, therapeutic and prognostic view this
is a totally different disease entity.
We believe that intravenous injection of MSC in therapy refractory JIA will be
tolerated and will enable us to estimate the effect to plan for further
studies.

To find out if intravenous MSC is a safe treatment for children with
therapy-resistant JIA

The study is a prospective patient-trial. The patient is it's own historic
control regarding efficacy. regarding safety the controlgroup is the
JIA-patients not treated with MSC as displayed by Pharmachild (a
Pharmacovigilance database for JIA patients).

Week -13: Regular clinical visit: Study explanation and handing over study
information and informed consent forms.
Wk -12 Regular telephone call after 1week to discuss the lab results as usual
and to ask about their opinion regarding the study and answering questions. If
they agree to the study the signed and dated informed consent forms are send
back to us in duplicate. Start of recording adverse events upon arrival of ICF.
Wk 0: regular clinical visit, MRI with contrast, venapuncture, MSC infusion
Wk 4: Extra clinical visit, venapuncture
Wk 8: Extra clinical visit, venapuncture, MRI and only if needed additional MSC
iv
Wk 12: Regular clinical visit, venapuncture
Wk 16: Extra clinical visit with venapuncture and only if needed additional MSC
iv
Wk 28: Stop recording mild adverse events (3 months after last possible
MSC-infusion)
Wk 26+39: Regular outpatient clinical visits
Wk 52: Regular outpatient clinical visit, MRI; end of study

*The second or third MSC will only be given to those patients who initially met
the ACR Ped 30 criteria but subsequently showed a loss of response before week
8 and/or 16.

Sample Size Calculation:
Using an 80% one-sided CI, it has been estimated that a pilot trial should have
at least 9% of the sample size of the main planned trial (Cocks,K. &
Torgerson,D.J. Sample size calculations for pilot randomized trials: a
confidence interval approach. J. Clin. Epidemiol. 66, 197-201 (2013). Using the
estimated effect size difference for the main trial and using a one-sided CI,
this allows us to calculate a sample size for a pilot trial, which will make
its results more useful than at present.
Looking at the trials leading to registration of new biologicals for the
indication of JIA the number of biological allocated patients in the randomized
phase contained 25 for etanercept , 68 for adalimumab and 60 for abatacept.
Therefore we feel that if MSC were to be studied with an equal RCT in the near
future, with 6 patients in this tolerability pilot study we fullfill the above
mentioned requirements.

We chose the dose of 1 million MSC/kg body weight because it has been used
widely as a dose for iv administration and doses of up to 160.8 million MSC
even have been safely injected in human joints.

MSC infusion (1-3x): MSC will be injected intravenously at a dose of 2 x 10E6
MSC/ per kg recipient body weight during 1 hour. There will be a 2 hour
post-infusional observation period.
In case of beneficial but waning effect the administration of MSC can be
repeated no earlier than 8 weeks after the former MSC infusion (week 8 or 16).
A maximum of 3 MSC infusions per patient is allowed.

Magnetic Resonance Imaging (MRI 3x): MRI will be performed 4 weeks before
(wk0), 8 weeks (wk8) and 1 year after MSC injection (wk52)
Our local protocol is used for magnetic resonance imaging of large peripheral
joints. Imaging will be performed with our Philips 3T scanner Gyroscan NT
Intera, Philips Medical Systems, Best, The Netherlands using a flex-M coil. The
following sequences are used: sagittal and coronal T1 TSE, sagittal T2 TSE,
sagittal PD TSE, transverse T2 SPAIR and sagittal T1 SPIR with gadolinium iv. A
contrast dose of 0.1 mmol/kg gadolinium (Gadovist®) is given if there are no
known contra-indications (standardlist at our radiology department). MRI will
be performed of a joint with blinding of the radiologist as to what treatment
has been given.

Clinical visits (at least 9 times in the first year, which is 4 more times than
for the typical JIA patient): -13, 0, 4, 8, 12, 16, 26, 39, 52 weeks
Thirteen weeks before first MSC infusion (wk -13), at the day of MSC-infusion
and every 4 weeks thereafter for the first 4 months (wk 4, 8, 12 and 16).
Further follow-up will be guided by patient complaints but at least every 13
weeks (wk26, 39 and 52). The visits will encompass complete medical history and
monitoring for side effects. Furthermore complete physical examination
including total joint count. Validated health and functionality related
questionnaires (see below at outcome measures) will be provided to the
parents/patients. Global assessments by the parents/patients measured with a
10-cm VAS.
Extensive physical examination will contain an evaluation of all joints as
described previously. In short the joints will be assessed as being normal,
warm, painful/tender, tender on passive motion, limited in motion. The degrees
of passive motion will be noted for all limited joints. Global assessments by
the physician measured with a 10-cm visual analogue scale (VAS)

Venapuncture (at least 7x in the first year instead of 4 times): at every
clinical visit -13, 0, 4, 8, 12, 16, 26, 39, 52 weeks.
The blood will be analyzed during each clinical visit for erythrocyte
sedimentation rate (ESR), C-reactive protein level (CRP), complete blood count,
leucocyte differentiation, ASAT, ALAT, LDH, BUN, Creatinine, total IgG,
Rheumatoid factor, anti-CCP. Furthermore lymphocyte subpopulations will be
analyzed by our FACS Canto machine and by their cytokine production measured
by Luminex as previously described by our own group: (effector and regulatory
subpopulations: including CD19+, CD4+, CD8+lymphocytes and Th1-, Th2-, Th17-,
FoxP3-Treg, IL10+-Treg phenotype) Serumcytokines will also be examined by
Luminex (including IL1, IL6, IL12, IL17, IL23, TNFα, IFNγ, IL4, IL10). At last
we will investigate the in vitro suppression by MSC and by T-regs of the
proliferation of the stimulated PBMC.

The burden of the participation is explained by the extra investigations when
compared to standard treatment in a typical JIA patient. Although the included
refractory patient will by definition not be the typical JIA patient we feel it
is best to compare to the typical JIA patient in order to maximally
discriminate the study procedures from regular care. Most likely the suitable
patient (if not participating to this study) would have been regularly seen
more than 4 times a year and would have had one or several MRI*s in such a
year.
In our study during a period of 65 weeks there will be compared to typical JIA
patients 3 additional clinical visits, 3 additional venapunctures (when
possible combined with MSC infusion or MRI), 1-3x MSC infusions (1-hour
infusion and 2-hour postinfusion observation), and 3 additional MRI*s with
contrast infusion (always combined with venapuncture).
Regarding the visits however we must note that refractory polyarticular JIA
patients included in this study already have failed abatacept which requires 4
weekly visits to our hospital for venapuncture and intravenous infusion. As for
many unregistered biologicals that can be experimentally used in JIA (with
uncertain outcome) such as ixekizumab, tocilizumab, brodalumab, golimumab the
patient needs to come every 4 weeks to the hospital for their injection.
We must also stress that in very refractory JIA patients we sometimes need to
make MRI*s with contrast every 3 months.
Compared to e.g. proceeding with autologous stem cell treatment or
arthroplasty-surgery we feel that the burden of our protocol is minimal.

Risks of participation are negligible (low chance of mild harm).
Systematic review of literature shows so far that MSC treatment is safe in
general and 196 RA patients as well. No association between acute infusional
toxicity, organ systemic complications, infection, death or malignancy was
detected. There was however a significant association between MSC and transient
fever.
We have stringent release criteria for our MSC (see IMPD). Lastly we will use
allogenic MSC which will be rejected more easily, thereby further reducing the
risks for longterm side effects.
The possible benefit is that patients might have less pain, less limitations,
better well-being, higher quality of life and a stem cell transplantation or
life-long invalidity might be prevented. This might prevent serious morbidity
and even mortality from SCT.
The study is group related since JIA is a unique disease that can only be
tested in JIA patients since there is no adult disease similar enough to
translate results from such a study to JIA patients without testing it in JIA.
Indeed this is the case for many drugs that need to be tested in JIA first
before they can be registered for JIA, not withstanding the results in RA.
Rituximab and hydroxychloroquine for example are almost never used in JIA while
they are registered for use in RA.