Stem cells from Cord Blood: Myths, reality and potential Elisabeth Semple, PhD Scientific Director Cells for Life Cord Blood Institute
Learning objectives Understand the current usage of stem cells from cord blood To be able to name three ways of over coming challenges with using cord blood Understand the current thinking on the mechanism of action for regenerative medicine 2
History of Cord Blood Transplantation and Banking -70s and -80s The early years -90s Establishing a new treatment Sibling to un-related -00 Expanding options Pediatric to adult -10 Regenerative medicine -72: 1st recorded use of CB -89: 1 st successful CB transplant -93: NYBC CBB established Mid-90s: publications of related and unrelated transplantations in children -98: Outcomes of 562 recipients Early -00: publications of engraftment in adult recipients -05: Usage of Double CB units for adults -08: 86 CB transplants in Canada -10: Accepted option for both children and adults -10: Regenerative medicine -11: Diabetes study -11: Case study on CP
Current status Transplantation: Cord blood is now a source of stem cells routinely used. Almost all studies published or presented are reinforcements of previous findings. Better outcomes with higher number of cells. Despite increase in Double transplants this is still the message Regenerative medicine: Watchful waiting. Many studies are done in China and Korea Cell dose (and what type of cell is needed) is unknown
Why chose Cord Blood Stem Cells? (Transplantation for hematological diseases) Timing Time between search and use Adult Stem Cells Generally 3 months Up to 10 months Cord blood Stem Cells 1 day 2 weeks Units stored and ready for use No Yes For patients that: - do not have a matched family donor - cannot wait 3 months for a search 5
Why chose Cord Blood Stem Cells? (Transplantation for hematological diseases) Chance of finding a suitable unit Adult Stem Cells Cord blood Stem Cells Chance of a full match? 50 million donors 400,000 units in public banks, many more in private banks Matching requirement Req. 6/6 match 8/8, 10/10 better 4/6 acceptable, 6/6 better Cord Blood: With adequate cell dose, the outcomes for 4/6, 5/6 and 6/6 HLA-matches are similar. 6
Why chose Cord Blood Stem Cells? (Transplantation for hematological diseases) Transplant-related morbidity Adult Stem Cells Cord blood Stem Cells Risk of graft v host disease High Low: naïve cells Long telomers No Yes Time to engraftment 7-10 days 21 days Longer time to engraftment = higher risk for infection
Why chose Cord Blood Stem Cells? (Transplantation for hematological diseases) Number of cells Number of cells High Adult Stem Cells Collect as much as needed Cord blood Stem Cells 1 log lower One time collection Current guideline for Cord Blood: TNC: >2.5 x10 7 /kg bodyweight (an average CB contains about 1.0 x10 9 TNC) TNC= Total Nucelated Cells Granulocytes, Lymphocytes, Monocytes, nrbcs, Stem cells CD34+ cells: >1.7 x10 5 /kg bodyweight (?) No commonly used as results difficult to compare Higher cell number required with HLA-mismatch 8
Algorithm for choice of stem cell source (Smith and Wagner, Br J Haematol 2009;147:246-61) 1 st choice 6/6 HLAmatched CB 2 nd choice 8/8 HLAmatched BM 5/6, 4/6 HLAmatched CB Malignant Disease Non-malignant Disease Pediatric Adult Pediatric Adult 6/6 HLAmatched CB 8/8 HLAmatched PBMC 8/8 HLAmatched BM 5/6, 4/6 HLAmatched CB 8/8 HLAmatched BM 6/6, 5/6 HLAmatched CB 3 rd choice 4/6 HLAmatched CB 8/8 HLAmatched PBMC 8/8 HLAmatched BM 6/6, 5/6 HLAmatched CB 4/6 HLAmatched CB 9
Cord blood challenges Relatively low number of stem cells available/unit compared with bone marrow Longer time to engraftment Strategies to over come this: 1. Increase the number of CD34 + cells 2. Improve homing 3. Improve patient care and treatment
Cord blood challenges Increase the number of CD34+ cells Ex vivo expansion Going on for years aim to shorten time to engraftment not yet quite there Notch-ligand based expansion Double unit transplants For adults very encouraging results Only one unit engrafts Combination of Expansion and double unit transplant Preliminary results encouraging: from 26 to 14.5 days to engraftment (n=11) Very expensive!! Collect more cells Rinse the placenta
Cord blood challenges Improve homing Priming with thawed partial unit Selection and expansion of ALDH br cells from 20% of the unit. Give the patient the remaining 80% first to prime the system. Express road to the bone marrow.. Pulse the CD34 cells with Prostaglandin E 2 Shortened the time to engraftment (50%) Decreased apoptosis Intra-bone injections By-pass the lungs Somewhat encouraging results
Sources of Stem Cells for Transplantation, NMPD Allogeneic use, 1998-2010 Which Diseases Can Be Treated with Cord Blood? Leukaemia Lymphoma Sickle cell anaemia Thallasaemia Immune system disorders Following chemotherapy for cancer Inborn metabolic errors Krabbe s Hurler s http://www.marrow.org/physician/urd_search_and_tx/number_of_allogeneic_tx_perfor/index.html
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Allogeneic vs Autologous use of Cord Blood in children (usage Worldwide, both public and family) 4000 3500 400 350 Traditional use Autologous use Other 3000 300 2500 2000 250 200 Diabetes Type I 1500 150 1000 100 500 0 50 0 Other brain disorders/ injuries Cerebral Palsy Allo Auto Ref: Verter F, Nietfield J. Abstract 157, ISCT, Philadelphia, 2010
Sibling or Matched Unrelated Donors Survival after related CB transplantation in children Survival after unrelated CB transplantation in children Gluckman E. Experimental Hematology, 2000
Outcomes after related and unrelated CB transplantation for hereditary BMFS. From 1994-2008 Related Unrelated n 20 44 Age (years) 5.7 5 HLA matching 6/6-100% 6/6-10% 5/6-58% Nucleated cells/kg 5 x10 7 6.1 x 10 7 GvHD (2 years cumulative data) Engraftment (neutrophil recovery) 11% 53% 95% 57% Bizzetto R. Haematologica 2011;96:134-41 16
Outcomes after related and unrelated CB transplantation for hereditary BMFS. Cell dose with unrelated donors Bizzetto R. Haematologica 2011;96:134-41 17
Van Rood et al. PNAS, Nov 2009 Non-inherited Maternal Antigens (NIMA) The baby develops tolerance to non-inherited antigens in-utero. Van Rood et al: Hypothesis: Mismatched CB grafts with a NIMA match to the mismatched antigen have improved outcome. Endpoints: 1: Transplant-related mortality 2: Neutrophil and platelet engraftment, GVHD, relapse, overall mortality and treatment failure. Study group: Patients receiving mismatched CB with NIMA match, n=79 Control group: Patients receiving mismatched CB, n=980
Probability of transplant-related mortality (TRM) for patients 10 years of age or older. van Rood J J et al. PNAS 2009;106:19952-19957 2009 by National Academy of Sciences
Time to absolute neutrophil count (ANC) 500/mm3 (at day 77) for the subset of patients transplanted with a CB unit with TNC per kilogram of body weight of <2.5 107. van Rood J J et al. PNAS 2009;106:19952-19957 2009 by National Academy of Sciences
Time to relapse for patients with myelogenous malignancies. van Rood J J et al. PNAS 2009;106:19952-19957 2009 by National Academy of Sciences
Non-inherited Maternal Antigens, cont. Van Rood et al: Conclusion: These preliminary results indicate that matching for cord blood NIMA could improve disease-free survival and may reduce leukemic relapse in patients suffering from hematological malignancy. Discussion: Can this explain the better outcomes in sibling transplants?
Clinical trials underway: o Cerebral Palsy (auto) o Juvenile diabetes (autologous) o Myocardial infarction (auto/allo) o Repair of heart valves (auto) o Spinal cord injury (auto/allo) o Stroke (auto/allo) o MS and other autoimmune diseases Research is underway for: Alzheimer s Disease Liver Disease Muscular Dystrophy Parkinson s Disease HIV Regenerative medicine: Potential of UCB Stem Cells
Cord blood transplantation for HIV?? Case report: A patient with HIV developed leukemia and required a stem cell transplantation At follow up it was discovered that the viral load was decreasing. Entry of HIV into cells requires CCR5-delta32 receptors on the lymphocytes Transplantation of CCR5-delta32 negative cells by chance led to decrease in viral load (39 months) 1% of Caucasians negative, mostly Scandinavians and Finns. Cord blood desirable as only 4/6 match is usually required. Should Cord Blood Banks test for CCR5? Ref: Hutter G. NEJM 2009 24
Regenerative medicine: How does it work? In vitro, cord blood stem cells can become almost any cell! Do the transplanted cells migrate to the injured site and become the cell needed? Neurons Beta-cells Myocardiocytes Or??? 25
Regenerative medicine: How does it work? Current theory of mechanism: Protection from inflammation Allows re-generation of the body s own tissues, nerves Protection In vivo: most of the effects seen are due to immuno-modulation and anti-inflammatory response In some studies they infuse all the cells from the cord blood. So do we need a combination of cells or a specific cell?? CB contains: Haematopoietic stem cells Mesenchymal cells Very small-embryonic-like stem cells Unrestricted somatic stem cells Endothelial precursor cells.. 26
Regenerative medicine: Which cell is really the effector cell?? Mesenchymal stromal cells one of the candidates Can be found in almost any tissue Non-immunogenic (?) In vitro: can differentiate into almost any cell type What is the effect in vivo? 1 st clinical trial published 1999 (Horwitz et al. Nat Med 1999;5:309) Cells from Bone Marrow Children with Osteogenesis Imperfecta Very good clinical results but they could never find any donor cells 26 clinical trials with mesenchymal cells from Cord Blood registered w NIH. Are mesenchymal cells from cord blood different?? In most of these trials the cells need to be expanded Will that change the cell properties? 27
Regenerative medicine: Does it really work? Diabetes Type I Autologous cord blood infused within the first year after diagnosis. Preliminary finding: Decreased need of insulin after 6 months 1 year follow up of 15 patients Use of autologous cord blood is safe. Insulin requirements were no different compared with historical control group. Conclusion: if there was an effect, it did not last Open questions: Prolonged honey-moon. Protective mechanism?? The whole unit of cord blood was given. Cell dose? Maybe many small doses? Which cell? Haller et al, Exp Hematol 2008, Haller, Diabetes Care 2009 28
Regenerative medicine: Does it really work? Ischemic brain injury, CP CB cells migrate to the site of injury Some differentiation Bystander effect Protects the brain from further injury by supressing the immune response Helps the brain heal itself 29
Regenerative medicine: Does it really work? CP Dr Kurtzberg at DUKE: May 2009 108 patients enrolled, 14 have been followed up 8 have shown functional improvement 2010 - Blinded study started. N=120 Estimated completion: 2012 Other NIH funded study is also on-going University of Georgia, n=40 Estimated completion: 2012 30
Regenerative medicine: Does it really work? CP: Report of 2 cases: Autologous cord blood + G-CSF Case 1 Case 2 Age of transplant 19 months 15 months Status before transplant Unable to stand or walk Spastic diplegia Increased muscle tone Hyperreflexia GMFCS* level before transplant III III Status after transplant At 36 months Can walk, run and swim Reduced spasticity GMFCS level after transplant I I Only stand briefly with orthotic gear At 23 months he can walk >30 min and swim. Reduced spasticity: can hold and manipulate toys Time to improvement Motor improvements after 7 weeks Could stand after 10 days *Gross Motor Function Classification System, Level III: walks using handheld mobility device, Level I: walks w/o limitation Papadopoulos K et al. Restor Neurol Neurosci 2011;29:17-22 31
Family and Public Cord Blood Banking A good quality sample is a good quality sample where ever it is stored
Family and Public Banking Different models of Cord Blood Banking Family banking Public Banking Sample belongs to the family Directed or autologous use Most samples stored For future use Traditional use New areas of use - regenerative medicine Storage for a fee Sample belongs to the Bank To be used by anyone in need Only the best samples kept - expensive to store samples No cost to the donor 33
Cord Blood Options Three choices Do nothing Donate to a Public Bank Save Discarded as Medical Waste Research 80-85% Medical Use 15-20% Store for Family Use 34
Thank you Dr Elisabeth Semple, Scientific Director Contact: esemple@cellsforlife.com 35