NIH and Mesoblast Partner for Clinical Trial in End-Stage Heart Failure


Mesoblast Limited has partnered with the National Heart, Lung, and Blood Institute (a branch of the National Institutes of Health or NIH) to conduct a large clinical trial that uses Mesoblast’s proprietary adult stem cell treatment in patients with advanced heart failure that requires an implantable Left Ventricular Assist Device (LVAD) to maintain proper circulatory support. The Canadian Institutes for Health Research and the National Institute of Neurological Disease and Stroke are also supporters of this trial.

Mesoblast is an Australian company whose Mesenchymal Precursor Cells (MPCs) have shown some promise in several pre-clinical studies and a few small clinical trials. The main objective in this study is to use the MPCs in heart failure patients and to examine the ability of MPCs to reduce the need for LVADs. Also, the study will ascertain is MPCs reduce long-term complications of LVAD transplantation, the most common of which is repeated hospitalizations.

This 120-patient study, to be conducted by the NIH-funded Cardiovascular Surgical Trials Network, will evaluate the effects of MPC transplantation into the hearts of patients with advanced heart failure. 150 million MPCs will be injected into the hearts of each patient and this product is being tested as an “off-the-shelf” medical product.

This new clinical trial builds upon previous successful but small trials in which 30 heart patients were treated with either 25 million MPCs or MPC culture medium during LVAD implantation. This was a double-blind, placebo-controlled study, and it showed that the MPC-treated patients tended to show higher rates of not needing their LVADs anymore 90 days after implantation and 12 months after implantation. This study was complicated by the fact that several patients died during the trial, which is not surprising because patients who received LVADs tend to be very sick. Nevertheless, these results were suggestive that the MPCs were effective. This study was published in the journal Circulation, which is an American Heart Association publication.

This second study will examine 150 patients who will receive a higher dose of the MPCs and a phase three study is on the board in collaboration with Teva Pharmaceutical Industries Ltd, which is Mesoblast’s development and commercial partner, which will examine 1,700 patients.

One of the first measurements examined in this study is how long after the treatment until the patient experiences their first adverse heart event. These are called HF-MACEs or heart failure-related major adverse cardiac events. If MPCs delay the onset of the patient’s first HF-MACE, then the cells might be making the heart healthier and stronger.

Congestive heart failure is a chronic condition characterized by an enlarger heart and insufficient blood flow to the organs and extremities of the body. According to the American Heart Association, congestive heart failure affected ~5.1 million people 20 years of age or older in the US in 2010, and there are 825,000 new cases diagnosed annually. 50% of heart failure patients die within five years of diagnosis.

30%-40% of heart failure patients suffer from moderate/severe class II/III heart failure with low ejection fractions and 10% have advanced heart failure (NYHA class IV heart failure). the only treatment options for end-stage or class IV heart failure are a heart transplant or mechanical support with a LVAD. Heart transplants cannot meet the large need due to donor availability, and permanent LVAD support is currently limited by clinical complications.

Mesenchymal Stem Cells from Fat Relieve Arthritis Pain for Up to Two Years


Regeneus is an Australian regenerative that has developed an experimental treatment for arthritis called HiQCells.  HiQCell is a stem cell treatment made from the patient’s own adipose (fat) tissue, and is subsequently injected into an affected joint or tendon. Regeneus has tested their HiQCell treatment in an independent clinical study that examined the efficacy of injections of HiQCells into the joints of patients with osteoarthritis of the knee.  The study examined 40 patients with knee osteoarthritis.  Half of these patients received the placebo and half HiQCell in a double-blinded study.  When asked about their pain levels six months after the procedure, patients in the placebo and HiQCell group ~45% of patients reported less pain and by 12 months after treatment 55% of patients in both groups reported less pain.  Thus both treatments relieved pain to a similar degree.  However, when the progression of the disease was examined, a very different result was observed.  As osteoarthritis progresses, some of the breakdown products of joint cartilage appear in urine and blood.  By collecting urine and blood samples from osteoarthritis patients, the progression of the disease can be readily tracked.  Blood and urine testing showed significantly less cartilage breakdown in the HiQCell group and significantly more breakdown in the patients in the placebo group who had advanced cartilage damage. Thus, even though the patients who received placebo had about the same level of pain reduction over the six-month period, it seems that their cartilage breakdown progressed at a faster rate.

Now a follow-up examination of these and other subjects who participated in this initial clinical study has revealed something surprising.  According to Regeneus, as of July 21, 2014, from a collection of 386 patients: 1) Pain has continued to decrease two years post-treatment; 2) One year after treatment, 63 of 86 patients reported more than a 30% reduction in pain;
3) Two years after treatment, 14 of 17 patients reported more than a 30 % reduction in pain and 14 patients experienced an average pain reduction of 84% at two years post-treatment; 4) Patients also reported significant improvements from pre-treatment in knee-function, sleep quality and reduced pain medications.  Finally, it is clear from these results that HiQCell is a safe therapy and well tolerated by patients, since the frequency and severity of adverse effects of patients who received HiQCell treatments were no different from those received the placebo.

The HiQCell Joint Registry established by Regeneus is the first of its kind in that the patients who participate in this study are subjected to long-term follow-up and undergo stem cell therapy using the patient’s own fat-derived stem cells. The HiQCell study has been approved by a human research ethics committee.  These 386 patients included in the Joint Registry will continue to be followed for up to 5 years with analysis updated regularly.

Professor Graham Vesey, CEO of Regeneus, comments: “The registry data is demonstrating that HiQCell has a therapeutic benefit for longer than 2 years. We are now also beginning to see very encouraging data from patients that have had cells frozen for future injections. This combination of the long-term effect from HiQCell and the successful storage of cells for repeat injections in the future, means that HiQCell can be used to treat joint pain for many years. This is particularly important for patients that are too young for joint replacement or are simply looking to delay joint replacement.”

Mesenchymal Stem Cells Improve Movement and Decrease Neurodegeneration in Ataxic Mice


Friedrich’s ataxia (FA) results from insufficient concentrations of a protein called Frataxin.  Frataxin serves as an iron metabolism protein that puts iron into proteins that need it.  Because several proteins that play crucial roles in energy metabolism in cells use iron, Frataxin is a very busy molecule and without sufficient quantities of Frataxin, energy metabolism decreases and metabolically active cells, such as nerves and muscles, weaken and die.

Frataxin crystal structure.

Frataxin crystal structure.

In patients with FA, the dorsal root ganglia, which lie just in front of the spinal cord, are the first to die off and degenerate.  Can stem cell treatments provide relief from the ravages of FA?

DRG

To test this possibility, Salvador Martinez and his colleagues from the University Miguel Hernández in Alicante, Spain examined two mouse populations, both of which harbored loss-of-function mutations in the Frataxin (FXN) gene.  Mice from both groups were injected with bone marrow-derived mesenchymal stem cells isolated from either wild-type or YG8 mice.  YG8 mice a genetically manipulated so that they suffer from a mouse form of FA that shows several similarities to human FA.  The mesenchymal stem cells injections were “intrathecal” injections, which means that they were directly injected into the nervous system.

As a result of the stem cell injections,  both groups of mice showed improved motor skills compared to nontreated mice.  The dorsal root ganglia also showed increased frataxin expression in the treated groups, and less cell death.

Why did the stem cell-injected mice fare better?  Further investigations revealed that the injected mesenchymal stem cells expressed the following growth factors:  NT3, NT4, and BDNF.  All of these growth factors can bind to specific receptors embedded in the membranes of those sensory neurons located within the dorsal root ganglia and buck up their survival, thus preventing them from dying.  The stem cell-treated mice also had increased levels of “antioxidant enzymes.”. These are enzymes found in our own cells that dispose of dangerous molecules.  Enzymes such as catalase, superoxide dismutase and so on are examples of antioxidant enzymes.  The stem cell-treated mice had higher levels of catalase and GPX-1 in their dorsal root ganglia, which is significant because YG8 mice show decreased levels of these antioxidant enzymes.

Interestingly, the results were not significantly different if the injected stem cells were isolated from wild-type or YG8 mice. In both cases injected mesenchymal stem cells ameliorated the condition of the FA mice.

In conclusion, transplantation of bone marrow mesenchymal stem cells, either the patient’s own stem cells or donated stem cells, is a feasible therapeutic procedure that might delay the onset of cell death in the dorsal root ganglia of patients with Friedreich’s ataxia.

An Entire Organ Grown Inside an Animal


For the first time, scientists from Scotland have reported that an entire, functional organ has been grown from scratch inside a laboratory animal. A Scottish research group successfully transplanted a small quantity of cells into a laboratory mouse that grew and developed into a functional thymus.

These findings were published in the journal Nature Cell Biology, and might open the door to new alternatives to organ transplantation. This research certainly shows great promise, but is still years away from clinical trials and reproducible human therapies.

If you are wondering what the thymus is, it serves as an integral part of the immune system. The thymus is located just above and slightly over the heart and produces a vital component of the immune system, called T-cells, which fight infections and regulate the immune response.

The thymus

The thymus

thymus location

 

A research team from the Medical Research Council Centre for Regenerative Medicine at the University of Edinburgh began this experiment with mouse embryonic fibroblasts.  These fibroblasts are found in the skin and connective tissue of the embryo.  These mouse embryonic fibroblasts were genetically engineered to expressed the FOXN1 gene, which encodes a transcription factor known as the “forkhead box N1″ protein.  The forkhead box N1 protein binds to DNA and activates the expression of genes necessary to make thymic epithelial cells.  Mice that do not have a functional copy of the FOXN1 gene a “nude” mice.  They are nude because they have no hair and have no thymus.  

Once engineered to express FOXN1, the fibroblasts began to differentiate into thymic epithelial cells.  The Scottish team mixed these genetically engineered fibroblasts with some other support cells and transplanted them into laboratory mice where they summarily formed a fully functional thymus.  Structurally the animal-grown thymus contained the two main regions – the cortex and medulla – and it also produced T-cells.

Prof Clare Blackburn, who was part of the research team, said it was “tremendously exciting” when the team realized what they had accomplished.  Blackburn told the BBC: “This was a complete surprise to us, that we were really being able to generate a fully functional and fully organised organ starting with reprogrammed cells in really a very straightforward way.  This is a very exciting advance and it’s also very tantalising in terms of the wider field of regenerative medicine.”

Such a procedure could benefit patients who need a bone marrow transplant and children who are born without a functioning thymus.  Likewise because our immune response diminishes as we age and out thymus shrivels, such a procedure might boost the waning immune system of aged patients.   could all benefit from such a procedure.

However, there are a number of problems to solve before this procedure can cross the bridge from animal studies to hospital therapies.  First of all, the recipient of these implants were nude mice that had no thymus and could not reject transplanted tissue.  Also, the use of embryonic fibroblasts would cause a robust immune response against them.  Some other cell type must be found for this procedure that grows robustly and does not cause transplantation rejection.

Researchers also need to be sure that the transplant cells do not pose a cancer risk by growing uncontrollably.  Prof Robin Lovell-Badge, from the National Institute for Medical Research, said: “This appears to be an excellent study.  This is an important achievement both for demonstrating how to make an organ, albeit a relatively simple one, and because of the critical role of the thymus in developing a proper functioning immune system.  However… the methods are unlikely to be easy to translate to human patients.”

This experiment is a testimony of just how far the field of regenerative medicine has come.  Already patients with lab-grown blood vessels, windpipes and bladders have benefited from advances in regenerative medicine. These tissue engineered structures have been made by “seeding” a patient’s cells into a scaffold which is then implanted.  The thymus in this case only required one injection of a cluster of cells.  While it is doubtful that other organs will be this easy to grow, it is an encouraging start.

Also, this experiment utilized “direct reprogramming” that did not require taking cells through the embryonic stage.  Instead one-gene reprogramming directed the cells to make thymus epithelium cells.  This almost certainly promises to be a much safer way to make cells for regenerative treatments.

Dr Paolo de Coppi, who pioneers regenerative therapies at Great Ormond Street Hospital, said: “Research such as this demonstrates that organ engineering could, in the future, be a substitute for transplantation.  Engineering of relatively simple organs has already been adopted for a small number of patients and it is possible that within the next five years more complex organs will be engineered for patients using specialised cells derived from stem cells in a similar way as outlined in this paper.  It remains to be seen whether, in the long-term, cells generated using direct reprogramming will be able to maintain their specialised form and avoid problems such as tumour formation.”

Accelerating Bone Regeneration with Combination Gene Therapy and Novel Scaffolds


A truly remarkable paper in the journal Advanced Healthcare Materials by Fergal J. O’Brien and his co-workers from the Tissue Engineering Research Group at the Royal College of Surgeons in Dublin, Ireland has examined a unique way to greatly speed up bone regeneration.

Mesenchymal stem cells from bone marrow (other locations as well) can differentiate into bone-making cells (osteoblasts) that will make architecturally normal bone under particular conditions. The use of mesenchymal stem cells and a variety of manufactured biomaterial matrices and administered growth factors enhance bone formation by mesenchymal stem cells (M. Noelle Knight and Kurt D. Hankenson, Adv Wound Care 2013; 2(6): 306–316; also see Marx RE, Harrell DB. Int J Oral Maxillofac Implants 2014 29(2)e201-9; and Kaigler D, et al., Cell Transplant 2013;22(5):767-77).

Protein growth factors tend to have rather short half-lives when applied to growth scaffolds. A better way to apply growth factors is to use the genes for these growth factors and apply them to “gene activated scaffolds.” Gene-activated scaffolds consist of biomaterial scaffolds modified to act as depots for gene delivery while simultaneously offering structural support and a matrix for new tissue deposition. A gene-activated scaffold can therefore induce the body’s own cells to steadily produce specific proteins providing a much more efficient alternative.

In this paper by O’Brien and his groups, the genes for two growth factors, VEGF and BMP2, were applied to a gene-activated scaffold that consisted of collagen-nanohydroxyapatite. VEGF drives the formation of new blood vessels, and this fresh vascularization, coupled with increase bone deposition, which is induced by BMP2, accelerated bone repair.

Mind you, the assays in the paper were conducted in cell culture systems. However, O’Brien and his colleagues implanted these gene-activated scaffolds with their mesenchymal stem cells into rats that had large gaps in their skulls. In this animal model system for bone repair, stem cell-mediated bone production, in addition to increased blood vessel formation accelerated bone repair in these animals. Tissue examinations of the newly-formed bone showed that bone made from gene-activated scaffolds with mesenchymal stem cells embedded in them made thicker, more vascularized bone than the other types of strategies.

This is not a clinical trial, but this preclinical trial shows that vascularization and bone repair by host cells is enhanced by the use of nanohydroxyapatite vectors to deliver a combination of genes, thus markedly enhancing bone healing.

Mesenchymal Stem Cells Derived from Induced Pluripotent Stem Cells are Epigenetically Rejuvenated


Earlier this year, Miltalipov and his research group published a paper in Nature that compared the genetic integrity of embryonic stem cells made from embryos, to induced pluripotent stem cells and embryonic stem cells made from cloned embryos.  All three sets of stem cells seemed to have comparable numbers of mutations, but the induced pluripotent stem cells had “epigenetic changes” that were not found in either stem cell line from cloned or non-cloned embryos.

Genetic characteristics have to do with the sequence of the DNA molecules that make up the genome of an organism.  Epigenetic characteristics have nothing to do with the sequence of DNA, but instead are the result of small chemicals that are attached to the DNA molecule.  These small chemical tags affect gene expression patterns.  Every cell has a specific epigenetic signature.

During development, the cells that will form our eggs and sperm in our bodies, the “primordial germ cells,” begin their lives in the outer layer of the embryo.  During the third week of life, these primordial germ cells or PGCs move like amoebas and wander into the yolk sac wall and collect near the exit of a sac called the “allantois.”  The PGCs are outside the embryo at this time or extraembryonal.  Incidentallyyolk sac is a terrible name for this structure, since it does not produce yolk proteins.  Therefore other textbooks have renamed it the “primary umbilical vesicle,” which is a bit of a mouthful, but it probably better than “yolk sac.”

 

1 - Primordial germ cells 2 - Allantois 3 - Rectum 4 - Ectoderm 5 - Foregut 6 - Primordial Heart 7 - Secondary yolk sac 8 - Endoderm 9 - Mesoderm 10 - Amniotic cavity

1 – Primordial germ cells
2 – Allantois
3 – Rectum
4 – Ectoderm
5 – Foregut
6 – Primordial Heart
7 – Secondary yolk sac
8 – Endoderm
9 – Mesoderm
10 – Amniotic cavity

The embryo around this time undergoes a bending process as a result of its growth and the head bends toward the tail (known as the cranio-caudal curvature) and then the sides of the embryo fold downwards and eventually fuse (lateral folding).  This bending of the embryo allows the PGCs to wander back into the embryo again between the fourth and sixth week.  The PGCs move along the yolk sac wall to the vitelline and into the wall of the rectum.  After crossing the dorsal mesentery (which holds the developing intestines in place) they colonize the gonadal or genital ridge (which is the developing gonad). During their journey, and while in the gonadal ridge, the PGCs divide many times.

1 - Rectum 2 - Vitelline 3 - Allantois 4 - Nephrogenic cord (pink) 5 - Gonadal ridge (green) 6 - Primordial germ cells (red dots) 7 - Heart prominence

1 – Rectum
2 – Vitelline
3 – Allantois
4 – Nephrogenic cord (pink)
5 – Gonadal ridge (green)
6 – Primordial germ cells (red dots)
7 – Heart prominence

When the PGCs move into the developing gonad, the chemical tags on their DNA are completely removed (rather famous paper – Lee, et al., Development 129, 1807–1817 (2002).  This epigenetic erasure proceeds in order for the PGCs to develop into gametes and then received a gamete-specific set of epigenetic modifications.  These epigenetic modifications also extend to the proteins that package the DNA into chromosomes – proteins called histones.  Specific modifications of histone proteins and DNA lead to gamete-specific expression of genes.  Once fertilization occurs, and the embryological program is initiated, tissue-specific epigenetic modifications are conveyed onto the DNA and histones of particular cell populations.

This is a long-winded explanation, but because many cancer cells have abnormal epigenetic modifications, these epigenetic abnormalities in induced pluripotent stem cells (iPSCs) have been taken with some degree of seriousness.  Although, there is little evidence to date that links the cancer-causing capabilities of iPSCs with specific epigenetic modifications, although it certainly affects the ability of these cells to differentiate into various cell types.

A paper has just come from the laboratory of Wolfgang Wagner from the Aachen University Medical School, in Aachen, Germany that derived iPSCs from mesenchymal stem cells from human bone marrow, and then in a cool one-step procedure, differentiated these cells into mesenchymal stem cells (MSCs).  These  iPS-MSCs looked the same, and acted the same in cell culture as the parent MSCs, and had the same gene expression profiles as primary MSCs.  However, all age-related and tissue-specific epigenetic patterns had been erased by the reprogramming process.  This means that all the tissue-specific, senescence-associated, and age-related epigenetic patterns were erased during reprogramming.  Another feature of these iPS-MSCs is that they lacked but the ability to down-regulate the immune response, which is a major feature of MSCs.

Thus, this paper by the Wagner lab shows that MSCs derived from iPSCs are rejuvenated by the reprogramming process.  Also, the donor-specific epigenetic features are maintained, which was also discovered by Shao and others last year.  This suggests that epigenetic abnormalities are not an inherent property of the derivation of iPSCs, and that this feature is not an intractable characteristic of iPSCs derivation and may not prevent these cells from being successfully and safely used in the clinic.  However, this might be a cell type-specific phenomenon.  Also, the loss of the immune system regulatory capabilities of these iPS-MSCs is troubling and this requires further work.

iPS-MSCs

3D Printed Facial Implant Approved by the FDA


Three-dimensional printing uses modified ink-jet printers to spray cells and biomaterials into shapes that mimic human organs, tissues and structures. These three-dimensional printers have been used to make a variety of implantable structures.

Last year, Oxford Performance Materials announced that they had successfully created a 3D-printed implant that could replace 75 percent of a patient’s skull. This OsteoFab Patient Specific Cranial Device was made of PEKK (Polyetherketoneketone) biomedical polymer and was printed by using CAD files that had been developed to personally fit each patient’s specific dimensions. PEKK is an ultra high performance polymer used in biomedical implants and other highly demanding applications. The PEKK polymer has the advantage of being biomechanically similar to bone. The Osteofab skull implant was approved by the FDA in February of 2013.

Osteofab

The success of OsteoFab laid the groundwork for the recent FDA approval of Oxford’s OsteoFab Patient-Specific Facial Device, a customizable implant for facial reconstruction.

ORM 3D printed facial implant

Implants like this are known as “biocompatible implants,” which behave mechanically, in this case, like real bone.  The techniques developed by Oxford Performance Materials allow engineers to fabricate pieces that match an individual patient’s specific facial dimensions and structure in a manner that reduces the overall cost of the procedures required to surgically reconstruct a face after devastating injury. Due to these technical advances pioneered by Oxford Performance Materials, facial implants can be fabricated very quickly, which allows the plastic surgeons to get the patient into surgery sooner rather than later.

“With the clearance of our 3D printed facial device, we now have the ability to treat these extremely complex cases in a highly effective and economical way, printing patient-specific maxillofacial implants from individualized MRI or CT digital image files from the surgeon,” said Scott DeFelice, CEO of Oxford Performance Materials, in a statement. “This is a classic example of a paradigm shift in which technology advances to meet both the patient’s needs and the cost realities of the overall healthcare system.”

Oxford’s 3D-printed Osteofab cranial implants also have FDA approval and could potentially be combined with these facial implants into a single device for treating severe cases.  Although these facial implants have not yet been used in the United States, Oxford said the implants are now available to doctors and hospitals.

From artificial fingertips to airway splints that help babies breathe, 3D printing has provided the means to address complex surgical repairs.  The good news is that skull caps and facial bones are just the beginning of what 3D printing technologies can achieve.  We may soon see FDA approval for other bones, like knee caps, hips, and even small bones in the fingers and hands.

It’s all a part of a growing wave that could make 3D printers just as common as MRI machines in the tool kits used by physicians to repair and heal injured people.