Adult mesenchymal stromal cells to regenerate the neonatal brain: the PASSIoN trial (Perinatal Arterial Stroke treated with Stromal cells IntraNasally)

Cerebral palsy (CP) is a heterogeneous syndrome with a prevalence between 1.0
and 2.4 per 1000 live births. Perinatal arterial ischemic stroke (PAIS) is one
of the most important etiologies for CP and occurs in about 1 per 2300 live
births. Unilateral spastic cerebral palsy (USCP), occurring in about 60% of the
infants and other common problems including epilepsy, cognitive, speech and
behavioral problems. Because of the large and long-lasting burden of the
consequences of PAIS for patients and society, development of a treatment
strategy for these vulnerable infants is urgently needed. The overall aim of
this project is to fill this void by developing an adult mesenchymal stem cell
(MSC) based treatment strategy to reduce the life-long consequences of neonatal
brain damage.

We have already demonstrated in a mouse model of neonatal ischemic infarction
that intracerebral application of murine adult bone marrow-derived MSC markedly
improves outcome. Treatment with MSC reduced infarct size by >45%, stimulated
formation of new neurons and oligodendrocytes, partially restored
cortico-spinal motor tract activity, and improved sensorimotor outcome.
Moreover, our most recent findings indicate that MSCs can be successfully
administered to the brain via an efficient non-invasive route, the nasal route.
Upon application to the nasal mucosa, MSCs cross the cribiform plate and
migrate into the brain via the rostral migratory route. The MSCs subsequently
accumulate predominantly in the infarcted area. Notably, MSCs delivered via the
nasal route reduce infarct size and improve motor function to the same extent
as MSCs administered intracranially/directly into the brain tissue.

In the preclinical part of this ZonMw study, experimental research to the
efficacy and in particular to the safety of allogenic MSC treatment in the
developing species, in which we focussed on inflammatory activity and formation
of malignancies in long-term studies, did not reveal any negative/adverse
effects concerning these complications in the MSC-treated animals as compared
to a non-treated control group. We furthermore found that it was possible to
safely manufacture *off the shelf* MSCs from healthy human donors in our
GMP-accredited Cell Therapy Facility (CT-F) of the University Medical Center
Utrecht and to culture them for nasal application to term newborns diagnosed
with PAIS.

This study will investigate whether bone marrow-derived allogeneic MSCs, as
administered by the nasal route, can induce the formation of neuronal tissue
and restore brain function in neonates who suffered from perinatal arterial
ischemic stroke (PAIS) compared to a matched group of historic untreated
controls. The ultimate goals of the present study is therefore to develop a
therapy using adult human allogenic MSCs to reduce or even to prevent the
lifelong consequences of PAIS-related brain damage in this group of term
newborns.

Single center open-label intervention study (all eligible consecutively
admitted patients with a PAIS involving the territory of the middle cerebral
artery will be treated with allogenic human MSCs and compared to matched
historical non-MSCS-treated PAIS patients).

Since (1) the absolute number of PAIS patients will be low, (2) the treatment
policy of the historical patient group not different from the study group
(except of course of the MSC treatment) and (3) determination of the
infarction volume and brain growth using advanced (volumetric) MRI are already
routinely used for a long time, we choose to use this model of investigation.
The most important reason to do so is to accomplish the present study in an
acceptable inclusion period of 2 years. We want to emphasize that the principal
reason of the present study is to show or at least to make it probable that
treatment with human adult MSCs provide us with a substantial better outcome
using this relatively stable PAIS model. In the long run this may open the
possibility to use MSCs also for the improvement of treatment modalities of
other perinatal complications such as perinatal hypoxic-ischemic encephalopathy
(birth asphyxia).

Based on preclinical data already obtained we anticipate the following ranges
for the treatment protocol: the infants will be treated with one dose of 50
million MSCs via the nasal route within within the first week of onset of
presenting clinical symptoms.

More in detail: prior to MSC administration, a bacterial culture will be taken
from both nostrils. Next: 30 minutes prior to delivery of the cells, the nose
will be cleaned with saline using standard procedures operative in the NICU.
Subsequently we will bring a sterile plastic (e.g. 10cc) syringe alternatevely
in both nostrils and drip the MSCs slowly into the nose. The syringe with MSC
will be packaged at the CT-F of the UMC Utrecht and will be transported to the
participating centers by the clinical research nurse.

Newborns of the other participating centers will be transported to the NICU of
the unversity Medical Center Utrecht after MRI confirmation of PAIS to undergo
the procedure as described above.

-The extra burden of the present study for the included infants is considered
to be very limited -to-non-existent given the fact that besides the nasal
treatment to apply the MSCs treatment is not different compared to the acting
treatment protocol. Nasal application of MSCs has been considered as
non-invasive.

-With respect to possible risks of the present MSC treatment, the most
important potential risk factors, inflammatory actions of MSC therapy with
allogenic human MSCs and an increased risk for malignancies, are intensively
investigated in the preclinical part of the present study. No single
indication has been found in experimental research in the developing animal
models that above mentioned complications occur in a higher incidence as
compared to non-MSC-treated animals, whereas the possibilty for a substantial
better short- and long-term outcome seems very realistic on the basis of our
previous experimental research data.