INSTINCT Study: Intranasal Stem Cells for Improving Neurodevelopmental Outcomes in Neonatal Encephalopathy

Problems around the time of birth causing a lack of oxygen to the baby can cause disordered brain function called neonatal encephalopathy (NE), which can result in long term brain damage and cerebral palsy. Cooling a baby by 3 degrees Celsius for three days as soon as possible after birth has been shown to be safe and leads to long term brain protection and improved outcome even to school age. Cooling is endorsed by NICE and adopted in neonatal intensive care units in UK for moderate to severe NE. However, although cooling is a major step forward for babies with NE, 44-53% still have adverse outcomes. This may be because cooling may be less effective with severe injury or there was prior exposure to infection and inflammation. Supplemental interventions to improve outcomes with and without cooling are greatly needed.

Over the last 10 years, several therapeutic agents have been studied as adjuncts to HT for babies, such as erythropoietin, melatonin, allopurinol, but there is currently no therapy apart from cooling for NE. The use of stem cells to successfully treat neonatal brain injury is emerging as a promising therapy. Human umbilical cord mesenchymal stem cells (huMSC) self renew and stimulate host brain cells to regenerate and repair, with superior anti-inflammatory properties than MSC from adult tissues. Importantly, although huMSC do not survive long term and replace damaged tissues themselves, they react to the needs of the ischemic cerebral environment by secretion of growth factors, cytokines and extracellular vesicles (EVs) to regulate damage and repair. These intrinsic adaptive properties of huMSC make them excellent candidates to treat the devastating effects of NE. The newborn brain is still in a developmentally active phase, leading to high efficiency of huMSC.

In a pilot pre-clinical model of NE, we observed brain protection with 2 doses of 30 million huMSC given intranasally 24h after a period of oxygen deprivation, whereas intravenous huMSC were not protective. We were able to detect these huMSC within the brain tissue. These data from male subjects suggest that huMSC (given intranasally) augment brain protection based on clinically relevant markers (recovery of aEEG and brain energy metabolism). For clinical translation, there is insufficient data on whether huMSC are protective in both normothermic and hypothermic milieu and whether there is different neuroprotective response from males and females.

Recently, EVs have been identified as the key mediators of stem cell paracrine signalling. EVs deliver their contents in the form of proteins, lipids, and nucleic acids; they overcome some limitations of cell therapies, including easier storage, low immunogenicity, passage through small vessels and no tumorigenic potential.

We propose the following 3 milestones as preparation for future clinical trials in babies with NE.

The first milestone will prepare the huMSC and EVs. We have access to clinical-grade huMSC manufactured by UCL.

The second and key milestone will assess safety and efficacy of 2 doses huMSC given intranasally at 12 and 36h after oxygen deprivation in both male and female subjects with and without cooling. We will assess outcome based on aEEG recovery, brain energy metabolism and histology. If positive we will meet MHRA with the aim to move to clinical trials.

The third milestone will assess safety and efficacy of 2 doses of EVs given intranasally at 12 and 36h after oxygen deprivation. The volume of EVs that produce an equivalent anti-inflammatory effect as 30 million huMSC will be used (previously determined in vitro studies in milestone 2b). This will inform the mechanism(s) through which beneficial effects of MSC therapy are mediated and may lead to refining the strategy for future clinical trials in babies with NE.

Neonatal Encephalopathy (NE) is an important cause of death and disability, affecting 1-3/1000 births in the UK and 10-25/1000 births in sub Saharan Africa. Even with therapeutic hypothermia (HT), over 50% of treated babies have adverse outcomes. HT protocols have been optimised, adjunct therapies are urgently needed. Cell therapy offers a paradigm shift in NE therapy.

Our primary aim is to assess neuroprotective effects of intranasal (IN) human umbilical cord stem cells (huMSC; clinical grade, manufactured at UCL). The proposal is based on pilot data in a male piglet model of hypoxia ischemia (HI). Compared to HT, IN 30 million huMSC at 24 & 48h after HI, with HT, improved: (i) recovery of aEEG over 72h; (ii) brain energy metabolism on magnetic resonance spectroscopy (MRS); (iii) white matter injury (TUNEL positive cells). There was no effect of intravenous huMSC. For clinical translation we must assess gender and temperature effects.

The beneficial anti-inflammatory and repair effects of huMSC are mediated mainly through paracrine effects, by secretion of extracellular vesicles (EVs) in response to the brain ischemic milieu. Promising data exists for IN EVs in stroke models; EVs are attractive as they overcome some limitations of huMSC. Our second aim is to assess the safety and efficacy of IN EVs in the piglet model (similar anti-inflammatory effect of 30 million huMSC).

The study will have 3 milestones:
- M1: Preparation of huMSC and EV

- M2A: Piglet Study 1. 2 doses IN huMSC at 12 & 36h with & without HT (4 groups, 16 piglets/group, (8 male, 8 female), total n=64). Of these n=3/group, PKH-labelled huMSC for TUNEL co-localization
M2B: Dose finding - in vitro EV anti-inflammatory equivalence to 30 million huMSC

- M3A: Piglet Study 2. 2 doses IN EV at 12 & 36h with & without HT (4 groups, 16 piglets/group (reduced to 10 if no gender effect), 75% of the controls used from M2, total n=40)
M3B: MHRA Scientific Advice Meeting

ACADEMIC IMPACT
This study, if positive, will provide advancement in the understanding of the beneficial effects of huMSC and EVs following hypoxia ischemia (HI) which will benefit all disciplines of medicine. Confirmation of the safety, efficacy of huMSC and EVs with and without hypothermia, in males and females and the comparative effects of huMSC and EVs will provide a rich source of information for future clinical trials in babies with NE.

ECONOMIC AND SOCIETAL IMPACT
If we demonstrate huMSC and EVs are safe and effective at reducing brain injury in HI this is likely to lead to clinical trials. NE is the 4th leading cause of death in children and accounts for 50 million disability life adjusted years worldwide. This research has the potential to reduce suffering from life-long neurologic disabilities and to significantly reduce the societal costs of caring for survivors with neonatal brain injury. The lifetime costs of caring for an individual with cerebral palsy (CP) is estimated at $1.15 million (2012 currency). Using a conservative estimate of 20% CP rates in NE infants treated with hypothermia and conservative estimate of NE incidence of 2/1000 in high resource settings, the economic burden in the US would be $1.7 billion in lifetime costs (similar pro-rata costs in the UK). NE is also estimated to produces additional lifetime costs of $1.6 billion for intellectual disability from NE. HT has been shown to reduce the burden of these costs, but despite HT there are still 50 percent of NE infants who develop adverse outcomes. If huMSC and EVs augments cooling, these costs will be reduced further.