Endometrial regenerative cells for treatment of heart failure: a new stem cell enters the clinic

Leo Bockeria, Vladimir Bogin, Olga Bockeria, Tatyana Le, Bagrat Alekyan, Erik J Woods, Amalia A Brown, Thomas E Ichim and Amit N Patel

Journal of Translational Medicine 2013, 11:56 doi:10.1186/1479-5876-11-56
Published: 5 March 2013

Heart failure is one of the key causes of morbidity and mortality world-wide. The recent findings that regeneration is possible in the heart have made stem cell therapeutics the Holy Grail of modern cardiovascular medicine. The success of cardiac regenerative therapies hinges on the combination of an effective allogeneic “off the shelf” cell product with a practical delivery system. In 2007 Medistem discovered the Endometrial Regenerative Cell (ERC), a new mesenchymal-like stem cell. Medistem and subsequently independent groups have demonstrated that ERC are superior to bone marrow mesenchymal stem cells (MSC), the most widely used stem cell source in development. ERC possess robust expansion capability (one donor can generate 20,000 patients doses), key growth factor production and high levels of angiogenic activity. ERC have been published in the peer reviewed literature to be significantly more effect at treating animal models of heart failure (Hida et al. Stem Cells 2008).Current methods of delivering stem cells into the heart suffer several limitations in addition to poor delivery efficiency. Surgical methods are highly invasive, and the classical catheter based techniques are limited by need for sophisticated cardiac mapping systems and risk of myocardial perforation. Medistem together with Dr. Amit Patel Director of Clinical Regenerative Medicine at University of Utah have developed a novel minimally invasive delivery method that has been demonstrated safe and effective for delivery of stem cells (Tuma et al. J Transl Med 2012). Medistem is evaluating the combination of ERC, together with our retrograde delivery procedure in a 60 heart failure patient, double blind, placebo controlled phase II trial. To date 17 patients have been dosed and preliminary analysis by the Data Safety Monitoring Board has allowed for trial continuation.The combined use of a novel “off the shelf” cell together with a minimally invasive 30 minute delivery method provides a potentially paradigm-shifting approach to cardiac regenerative therapy.

http://www.translational-medicine.com/content/11/1/56/abstract

Medistem Inc. Annual Letter to Shareholders

SAN DIEGO, CA–(Marketwire – Jan 4, 2013) – Medistem Inc. ( PINKSHEETS : MEDS ) today issues the following letter to shareholders.

Dear Fellow Shareholders,

2012 was marked by significant progress in the development of the Endometrial Regenerative Cell (ERC), our new universal donor “stem cell drug.” Most significantly, we initiated a double blind, placebo controlled clinical study in patients with end stage heart failure, in which ERC were administered via the Medistem’s patent-pending minimally invasive procedure. The clinical trial comprises three escalating doses of ERC with cohorts of 20 patients per dose. To date 14 patients have been treated with no adverse effects, thus demonstrating feasibility of the administration procedure, as well as safety of the cells. Because it is a double blind study, efficacy will not be known until the trial is completed. The clinical trial is being conducted at the Backulev Center for Cardiovascular Surgery in Moscow, Russia, by Academician Leo Bockeria. The company also initiated a 15 patient critical limb ischemia trial in China in collaboration with Shanghai Jia Fu Medical Apparatus Inc. To date two patients have been treated. The trial is based on the Medistem critical limb ischemia study that has been cleared by the FDA.

In addition, we licensed from Yale University the world-wide rights for a patent application using ERC to treat Type 1 diabetes. We also initiated a program in type 1 diabetes, with the goal of filing an Investigational New Drug application before the end of 2013 to allow for clinical trial initiation.

In 2012, researchers at the National Institutes of Health (NIH) independently verified and published a peer reviewed article confirming ERC possess a markedly higher expression of genes associated with new blood vessel formation and stem cell potency compared to bone marrow mesenchymal stem cells. The publication may be found at http://www.translational-medicine.com/content/pdf/1479-5876-10-207.pdf

In addition, our intellectual property was further enhanced with the issuance of patent #8,241,621 covering the use of fat derived stem cells for treatment of autoimmune conditions such as rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. We have also filed 2 patent applications covering the use of ERC for radiation protection and treatment of traumatic brain injury.

Also, in collaboration with several corporate and academic institutions we published a total of 7 peer reviewed papers in 2012 on collaborative breakthroughs we made in the areas of hepatitis, cancer, and prevention of transplant rejection.

Additionally, this year we added two new advisory board members including Gene Ray, Ph.D., and Alexander Gershman, M.D., Ph.D. Dr. Ray was founder of the Titan Corporation, where he served as CEO and a director of the corporation since the company’s inception in 1981. In 2011, Titan Corporation was acquired by L-3 Communications for $2.6 billion. Dr. Gershman is one of the first surgeons in the world to apply the method of laparoscopic surgery and robotic-assisted surgery to urology. He currently holds several hospital appointments, including: Director of Institute of Advanced Urology at the Cedars-Sinai Medical Center; Director of Urologic Laparoscopy in the Division of Urology, and Harbor-UCLA Medical Center.

Finally, this year marked a major transition in the leadership of the company. I was appointed to the position of CEO on October 26 and Dr. Thomas Ichim transitioned to the position of President and Chief Scientific Officer. Dr. Ichim has done an outstanding job leading the company for the past four years and I look forward to working closely with him at commercializing the ERC product.

In 2013 our objective will be to meet the following milestones:
•Return to “fully reporting” status and listing on the OTCBB
•Appointment of at least one new board member
•Initiation of the FDA cleared critical limb ischemia trial in the USA
•Completing enrollment in the RECOVER-ERC double blind cardiac trial
•Filing an IND for type 1 diabetes.

I want to end by thanking our loyal shareholders for their continued support as Medistem continues on its mission to generate the first practical “stem cell medicine.”

Sincerely Yours,

Dr. Alan Lewis
Chief Executive Officer
Medistem Inc.

About Medistem
Medistem Inc. is focused on the development of the Endometrial Regenerative Cell (ERC), a universal donor adult stem cell product. ERCs possess specialized abilities to stimulate new blood vessel growth and can differentiate into lung, liver, heart, brain, bone, cartilage, fat and pancreatic tissue. These unique properties have applications for treatment of critical limb ischemia (CLI), congestive heart failure (CHF), neurodegenerative diseases, liver failure, kidney failure, and diabetes. ERCs have been cleared by the FDA to begin studies in the United States.

ERCs have several distinguishing advantages to other stem cell therapies: a) Non-invasive method of collection; b) Unlimited supply of cells; isolated from menstrual blood of young healthy donors; c) Economical and scalable to manufacture; d) Exert higher therapeutic activity compared to other stem cells; and e) demonstrated safe in animal and pilot human studies.

Cautionary Statement
This press release does not constitute an offer to sell or a solicitation of an offer to buy any of our securities. This press release may contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking information. Factors which may cause actual results to differ from our forward-looking statements are discussed in our Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission.
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.
Contact:.
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Thomas Ichim, Ph.D.
President and Chief Scientific Officer
Medistem Inc.
9255 Towne Centre Drive
Suite 450
San Diego, CA 92122
858 349 3617
www.medisteminc.com

2013-01-14T17:14:08+00:00 January 14th, 2013|medistem, News, Stem Cell Research|

Medistem Advances Type 1 Diabetes Stem Cell Technology Licensed From Yale

SAN DIEGO, CA — (Marketwire) — 09/12/12 — Medistem Inc. (PINKSHEETS: MEDS) announced today completion of the first phase of a joint project with the Shumakov Research Center of Transplantology and Artificial Organs of the Russian Federation and its Russian and CIS licensee ERCell. The collaboration is based on using Endometrial Regenerative Cell (ERC) technology licensed from Yale University to treat type 1 diabetes.

Dr. Viktor Sevastianov, Head and Professor of the Institute of Biomedical Research and Technology, within the Shumakov Center, demonstrated safety and feasibility of ERC injection in experimental animal models of diabetes. Additionally, the studies demonstrated that the cell delivery technology developed by Dr. Sevastianov’s laboratory can be used to enhance growth of ERC. These experiments are part of the process for registration of “new pharmacological substances,” which is the first step towards drug approval in Russia.
“Type 1 diabetes is a significant problem in the Russian Federation. Our laboratory has been working developing various delivery formulations for cell therapy, such as SpheroGel, which is registered in Russia,” said Dr. Sevastianov. “Given that the ERC can be produced in large quantities, is a universal donor cell, and already is approved for clinical trials in both the USA and Russia, we are optimistic our collaboration will lead to a viable commercial product for the type 1 diabetes Russian population.”
Medistem discovered ERCs in 2007, and they appear to possess “universal donor” properties, allowing the cells derived from one donor can treat multiple unrelated recipients. According to Medistem’s current FDA cleared production scheme, one donor can generate 20,000 patient doses. Medistem licensed technology from Yale University for generating insulin producing cells from ERC. A publication describing the technology may be found at http://www.ncbi.nlm.nih.gov/pubmed/21878900.

“Our vision is to combine SpheroGel, which is a clinically-available cell delivery vehicle in Russia, together with Medistem’s ERC and technology from Yale University to generate a commercially-viable product for clinical trials in type 1 diabetes patients,” said Thomas Ichim, CEO of Medistem.

Medistem has outlicensed the Russian and CIS rights to ERC and related products to ERCell LLC, a St. Petersburg-based biotechnology company. Under the agreement, Medistem owns all data generated and will receive milestone and royalty payments.
“By working with leading investigators in Russia and the USA, we seek to be the leaders in a new era of medicine in Russia,” said Tereza Ustimova, CEO of ERCell.”

Cautionary Statement This press release does not constitute an offer to sell or a solicitation of an offer to buy any of our securities. This press release may contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking information. Factors which may cause actual results to differ from our forward-looking statements are discussed in our Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission.

Contact: Thomas Ichim Chief Executive Officer Medistem Inc. 9255 Towne Centre Drive Suite 450 San Diego, CA 92122 858 349 3617 www.medisteminc.com twitter: @thomasichim
Source: Medistem Inc.

2012-09-13T17:37:45+00:00 September 13th, 2012|Diabetes, News, Stem Cell Research|

Endometrial Stem Cells Yeild Postive Clinical Trial Results for Heart Disease

More progress reported on the treatment of heart disease with endometrial stem cells. Neil Riordan, PhD is one of the early pioneers of endometrial stem cell technology. Dr. Riordan is also the Founder and President of the Stem Cell Institute in Panama City, Panama.

Positive Two-Month Data From RECOVER-ERC Congestive Heart Failure Trial

SAN DIEGO, CA–(Marketwire – Jun 4, 2012) – Medistem Inc. (PINKSHEETS: MEDS) announced today positive safety data from the first 5 patients enrolled in the Non-Revascularizable IschEmic Cardiomyopathy treated with Retrograde COronary Sinus Venous DElivery of Cell TheRapy (RECOVER-ERC) trial. The clinical trial uses the company’s “Universal Donor” Endometrial Regenerative Cells (ERC) to treat Congestive Heart Failure (CHF).

According to the study design, after 5 patients enter the trial, they must be observed for a two month time period before additional patients are allowed to enter the study. Patient data was analyzed by the study’s independent Data Safety Monitoring Board (DSMB), which concluded that based on lack of adverse effects, the study be allowed to continue recruitment.

“Medistem is developing a treatment for CHF that uses a 30-minute catheter-based procedure to administer the ERC stem cell into the patients’ hearts. The achievement of 2 month patient follow-up with no adverse events is a strong signal for us that our new approach to this terrible condition is feasible,” said Thomas Ichim, CEO of Medistem.

The RECOVER-ERC trial will treat a total of 60 patients with end-stage heart failure with three concentrations of ERC stem cells or placebo. The clinical trial is being conducted by Dr. Leo Bockeria, Chairman of the Backulev Centre for Cardiovascular Surgery, in collaboration with Dr. Amit Patel, Director of Clinical Regenerative Medicine at University of Utah.

“As a professional drug developer, I am very optimistic of a stem cell product that can be used as a drug. The ERC stem cell can be stored frozen indefinitely, does not need matching with donors, and can be injected in a simple 30-minute procedure into the heart,” said Dr. Sergey Sablin, Vice President of Medistem and co-founder of the multi-billion dollar NASDAQ company Medivation.

Currently patients with end-stage heart failure, such as the ones enrolled in the RECOVER-ERC study, have no option except for heart transplantation, which is limited by side effects and lack of donors. In contrast to other stem cells, ERC can be manufactured inexpensively, do not require tissue matching, and can be administered in a minimally-invasive manner. Animal experiments suggest ERC are more potent than other stem cell sources at restoring heart function. The FDA has approved a clinical trial of ERC in treatment of critical limb ischemia in the USA.

About Medistem Inc.
Medistem Inc. is a biotechnology company developing technologies related to adult stem cell extraction, manipulation, and use for treating inflammatory and degenerative diseases. The company’s lead product, the endometrial regenerative cell (ERC), is a “universal donor” stem cell being developed for critical limb ischemia and heart failure. A publication describing the support for use of ERC for this condition may be found at http://www.translational-medicine.com/content/pdf/1479-5876-6-45.pdf.

Cautionary Statement
This press release does not constitute an offer to sell or a solicitation of an offer to buy any of our securities. This press release may contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking information. Factors which may cause actual results to differ from our forward-looking statements are discussed in our Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission.

Medistem Contact:

Thomas Ichim
Chief Executive Officer
Medistem Inc.
9255 Towne Centre Drive
Suite 450
San Diego
CA 92122
858 349 3617
858 642 0027
www.medisteminc.com
twitter: @thomasichim

2012-06-06T17:50:59+00:00 June 6th, 2012|Adult Stem Cells, Heart Disease, News, Stem Cell Research|

Medistem Signs Exclusive Worldwide License With Yale University for Treatment of Type 1 Diabetes Using Stem Cells

Acquisition of Intellectual Property and Data Leads to Expansion of Medistem Therapeutic Pipeline

SAN DIEGO, CA, Mar 07, 2012 (MARKETWIRE via COMTEX) — Medistem Inc. (pinksheets:MEDS) and Yale University have signed an exclusive worldwide licensing agreement covering the generation of pancreatic islets from stem cells such as the Endometrial Regenerative Cell (ERC). These pancreatic islets have effectively treated diabetes in animal models.

Professor Hugh Taylor of Yale University, inventor of the technology, made international headlines in September 2011 when he published his findings in the peer-reviewed journal Molecular Therapy.

“Medistem is the first company to develop clinical-grade endometrial-derived stem cells and initiate trials in humans,” said Professor Taylor. “Since Medistem’s Endometrial Regenerative Cells are manufactured inexpensively, can be used as an ‘off the shelf’ product, and to date appear safe in human subjects, I am very excited to see diabetes added to the list of diseases that can potentially be treated with Medistem’s ERCs.”

Medistem is currently in two clinical trials with ERCs: One for critical limb ischemia and a second for congestive heart failure, both of which are complications of uncontrolled diabetes.

“Type 1 diabetes is a rapidly growing poorly-served market. There is great optimism that cell-based therapies can address not only pancreatic degeneration but also the underlying immunological causes,” said Dr. Alan Lewis, former CEO of the Juvenile Diabetes Research Foundation, the largest non-profit organization focused on development of new therapeutic approaches for this disease. “The ERC is the newest adult stem cell to enter clinical trials. Based on this unique source of cells, as well as their immune modulatory properties, we believe this work may be expanded into other autoimmune diseases.”

About Medistem Inc. Medistem Inc. is a biotechnology company developing technologies related to adult stem cell extraction, manipulation, and use for treating inflammatory and degenerative diseases. The company’s lead product, the endometrial regenerative cell (ERC), is a “universal donor” stem cell being developed for critical limb ischemia and congestive heart failure. A publication describing the support for use of ERC for this condition may be found at http://www.translational-medicine.com/content/pdf/1479-5876-6-45.pdf . ERC can be purchased for scientific use through Medistem’s collaborator, General Biotechnology http://www.gnrlbiotech.com/?page=catalog_endometrial_regenerative_cells .

Cautionary Statement This press release does not constitute an offer to sell or a solicitation of an offer to buy any of our securities. This press release may contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking information. Factors which may cause actual results to differ from our forward-looking statements are discussed in our Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission.

2012-03-12T18:11:33+00:00 March 12th, 2012|Adult Stem Cells, News, Stem Cell Research|

Medistem Begins Phase II Clinical Trial for Heart Failure

Medistem Inc announced today treatment of 3 heart failure patients in the Non-Revascularizable IschEmic Cardiomyopathy treated with Retrograde COronary Sinus Venous DElivery of Cell TheRapy (RECOVER-ERC) trial. The trial is aimed at assessing safety and efficacy of the company’s Endometrial Regenerative Cell (ERC) stem cell product in 60 heart failure patients who have no available treatment options. The cells were discovered by Dr. Neil Riordan and the team at Medistem. The “Universal Donor” adult stem cells will be administered using a novel catheter-based retrograde administration methodology that directly implants cells in a simple, 30 minute, procedure.

“We are honored to have had the opportunity to present at the prestigious Cardiovascular Stem Cell Research Symposium, alongside companies such as Athersys, Aastrom, Pluristem, Cardio3, Cytori, and Mesoblast,” stated Thomas Ichim, CEO of Medistem. “The RECOVER-ERC trial is the first trial combining a novel stem cell, with a novel administration procedure. Today cardiac administration of stem cells is relatively invasive and can only be performed at specialized institutions, we feel the retrograde procedure will circumvent this hurdle.”

Medistem has been focusing on the endometrium because this is a unique tissue in that it undergoes approximately 500 cycles of highly vascularized tissue growth and regression within a tightly controlled manner in the lifetime of the average female. One of the first series of data describing stem cells in the endometrium came from Prianishnikov in 1978 who reported that three types of stem cells exist: estradiol-sensitive cells, estradiol- and progesterone-sensitive cells and progesterone-sensitive cells.

Interestingly, a study in 1982 demonstrated that cells in the endometrium destined to generate the decidual portion of the placenta are bone marrow derived, which prompted the speculation of a stem cell like cell in the endometrium. Further hinting at the possibility of stem cells in the endometrium were studies demonstrating expression of telomerase in endometrial tissue collected during the proliferative phase. One of the first reports of cloned stem cells from the endometrium was by Gargett’s group who identified clonogenic cells capable of generating stromal and epithelial cell colonies, however no differentiation into other tissues was reported. The phenotype of these cells was found to be CD90 positive and CD146 positive. The cells isolated by this group appear to be related to maintaining structural aspects of the endometrium but to date have not demonstrated therapeutic potential. In 2007, Meng et al, used the process of cloning rapidly proliferating adherence cells derived from menstrual blood and generated a homogenous cell population expressing CD9, CD29, CD41a, CD44, CD59, CD73, CD90, and CD105 and lacking CD14, CD34, CD45 and STRO-1 expression. Shortly after, Patel’s group reported a population of cells isolated using c-kit selection of menstrual blood mononuclear cells. The cells had a similar phenotype, proliferative capacity, and ability to be expanded for over 68 doublings without induction of karyotypic abnormalities. Interestingly both groups found expression of the pluripotency gene OCT-4 but not NANOG. More recent investigations have confirmed these initial findings. For example, Park et al demonstrated that endometrial cells are significantly more potent originating sources for dedifferentiation into inducible pluripotent cells as compared to other cell populations. Specifically, human endometrial cells displayed accelerated expression of endogenous NANOG and OCT4 during reprogramming compared with neonatal skin fibroblasts. Additionally, the reprogramming resulted in an average colony-forming iPS efficiency of 0.49 ± 0.10%, with a range from 0.31-0.66%, compared with the neonatal skin fibroblasts, resulting in an average efficiency of 0.03 ± 0.00% per transduction, with a range from 0.02-0.03%. Suggesting pluripotency within the endometrium compartment, another study demonstrated that purification of side population (eg rhodamine effluxing) cells from the endometrium results in a population of cells expressing transdifferentiation potential with a genetic signature similar to other types of somatic stem cells.

Given the possibility of ERC playing a key role in angiogenesis, Murphy et al utilized an aggressive hindlimb ischemia model combined with nerve excision in order to generate a model of limb ischemia resulting in limb loss. ERC administration was capable of reducing limb loss in all treated animals, whereas control animals suffered necrosis. In the same study, ERC were demonstrated to inhibit ongoing mixed lymphocyte reaction, stimulate production of the anti-inflammatory cytokine IL-4 and inhibit production of IFN-g and TNF-alpha. It is important to note that the animal model involved administration of human ERC into immunocompetent BALB/c mice. The relationship between angiogenesis and post myocardial infarct healing is well-known. Given previous work by Umezawa’s group demonstrating myocytic differentiation of ERC-like cells, administration of ERC into a model of post infarct cardiac injury was performed. Recovery was compared to bone marrow MSC. A superior rate of post-infarct recovery of ejection fraction, as well as reduction in fibrosis was observed with the ERC-like cells. Furthermore, it was demonstrated that the cells were capable of functionally integrating with existing cardiomyocytes and exerted effects through direct differentiation. The investigators also demonstrated in vitro generation of cardiomyocyte cells that had functional properties.

The RECOVER-ERC TRIAL that has begun will recruit 60 patients with congestive heart failure, which will be randomized into 3 groups of 20 patients each. Group 1 will receive 50 million ERC, Group 2 will receive 100 million and Group 3 will receive 200 million. Cells will be administered via catheter-based retrograde administration into the coronary sinus, a 30 minute procedure developed by Dr. Amit Patel’s Team. Each group will comprise of 15 patients receiving cells and 5 patients receiving placebo. Efficacy endpoints include ECHO and MRI analysis, which will be conducted at 6 months after treatment. The trial design is similar to the recent Mesoblast Phase II cardiac study, in order to enable comparison of efficacy.

2012-01-30T18:42:22+00:00 January 30th, 2012|Adult Stem Cells, Heart Disease, News, Stem Cell Research|

Differences between Stem Cells from the Placenta and Bone Marrow

Fazekasova et al. Mesenchymal stem cells were historically isolated from the bone marrow as an adherent stem cell population capable of “orthodox” differentiation, meaning that they have ability to become bone, cartilage, and fat. Further research revealed that these cells are also capable of “non-orthodox” differentiation, that is, becoming neurons, hepatocytes, insulin producing cells, and lung cells. Given the high number of growth factors secreted by mesenchymal stem cells, numerous companies have sought to develop therapeutic products from mesenchymal stem cells. For example, Osiris Therapeutics has been developing bone marrow mesenchymal stem cells as a treatment for Graft Versus Host Disease. Athersys has been using bone marrow derived mesenchymal-like cells for treatment of heart disease, and Mesoblast has been using these cells for treatment of bone injury.

A new generation of companies has been focusing other mesenchymal-like cells derived from other tissues. For example, Medistem Inc has identified endometrial regenerative cells (ERC), a type of mesenchymal-like stem cell that is found in the endometrium and appears to have higher ability to produce growth factors that stimulate new blood vessel production as compared to other sources of mesenchymal stem cells. General Biotechnology LLC has been developing tooth derived mesenchymal stem cells for treatment of neurological disorders. Celgene has been using placental-derived mesenchymal stem cells for treatment of critical limb ischemia, a disorder associated with poor circulation of the legs.

Given that there appear to be various sources of mesenchymal stem cells, an important question is how do these cells compare when they are used in experiments side by side. In a paper published this month, placental derived and bone marrow derived mesenchymal stem cells were compared. The scientists found that higher numbers of mesenchymal stem cells could be isolated from the placenta as compared to the bone marrow. Interestingly, placental mesenchymal stem cells were found to be comprised of both fetal and maternal origin.

One of the critical features of mesenchymal stem cells is that they are able to be used without need for matching with the recipient. This is because mesenchymal stem cells are historically known to be “immune privileged”. One of the experiments that the scientists did was to examine whether there is a difference between the bone marrow and placentally derived mesenchymal stem cells in terms of immunogenicity.

Placentally derived mesenchymal stem cells expressed lower levels of the immune stimulatory molecule HLA class I and higher levels of the immune suppressive molecules PDL-1 and CD1a, compared to bone marrow derived mesenchymal stem cells. However, when both cell types were treated with interferon gamma, the placentally derived mesenchymal became much more immune stimulatory as compared to the bone marrow cells. Furthermore it appeared that direct incubation with T cells resulted in higher T cell stimulation with the placental mesenchymal stem cells as compared to the bone marrow cells. Thus from these data it appears that bone marrow derived mesenchymal stem cells are more immune privileged as compare to placental derived cells.

Protein Found on Endometrial Regenerative Cells Inhibits Immune Attack

Medistem Inc. (PINKSHEETS: MEDS) announced today publication of a peer reviewed paper identifying a molecule found on the company’s lead product, the universal donor Endometrial Regenerative Cell (ERC), as a key component of cellular escape from immune attack. The study, entitled “Resistance of neonatal porcine Sertoli cells to human xenoantibody and complement-mediated lysis is associated with low expression of alpha-Gal and high production of clusterin and CD59” was published in the journal Xenotransplantation as a collaboration between Medistem and the Institute of Organ Transplantation, Tongji Hospital, in Wuhan, China.

The study found that CD59, a molecule made by ERC, plays an important role in protecting cells from immune rejection when placed in contact with immune components from another species. The ERC is a mesenchymal-like stem cell that Medistem discovered in 2007 capable of generating heart, lung, brain, muscle, blood vessel, pancreas, liver, fat and bone tissue. The original description of this cell, which won the “Publication of the Year Award” may be found at http://www.translational-medicine.com/content/pdf/1479-5876-5-57.pdf.

“One of the fundamental aspects of Medistem’s lead product, the Endometrial Regenerative Cell (ERC), is its ability to function without the need for tissue matching. In other words, the ERC stem cells act as universal donors. We have previously published that human ERC are effective in treating mice having a condition that resembles critical limb ischemia (see paper http://www.translational-medicine.com/content/pdf/1479-5876-6-45.pdf ). We now believe that expression of the molecule CD59 on ERC may be one of the mechanisms by which these human cells can be used not only as a universal donor for humans, but also for the treatment of numerous diseases across a variety of animal species.” Said Thomas Ichim, CEO of Medistem.

Medistem has filed an IND with the FDA for treatment of critical limb ischemia (severe obstruction of the arteries that leads to decreased blood flow to the extremities) with ERC. Currently the company is in the process of completing additional experiments requested by the FDA before clinical trials can commence. Through physician-initiated compassionate use mechanisms Medistem has already published on human use of ERC in treatment of heart failure, Duchenne Muscular Dystrophy, and multiple sclerosis. A recent peer-reviewed paper describing ERC in treatment of heart failure may be found at http://www.intarchmed.com/content/pdf/1755-7682-3-5.pdf.