Malaysia Spearheads Stem Cell Research

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The Ministry of Health (MOH) Ampang Hospital is embarking on a pioneering stem cell research exploring the use of mesenchymal stem cells (MSCs) in acute graft-versus-host-disease (aGVHD). While this innovative treatment has already been approved in several countries, it has so far only been used as salvage therapy after failing steroids and other immunosuppresants, and rarely employed as a front-line therapy. Steroid refractory aGVHD has a dismal prognosis with mortality in excess of 90% and no viable second-line options.1Working in collaboration with Cytopeutics®, a local company with an impressive track record of basic and clinical trials in stem cell, this Phase I-II double blind randomized clinical trial has been approved by the Medical Research Ethics Committee (MREC) and the National Stem Cell Ethics and Research Sub-committee (NSCERT). More centres are expected to participate in the trial locally and abroad including Singapore and Australia. The success of the treatment will provide a real chance of the patient surviving against the odds as well as put Malaysia on the map in the field of stem cell advances.

Graft-Versus-Host-Disease (GVHD)

Graft-versus-host-disease (GVHD) is said to occur when the cells from the donor, particularly the T-lymphoctyes, attack the host organs following allogeneic hematopoietic stem cell transplantation (HSCT) despite efforts to match the donor and recipient. In GVHD the host tissue is damaged by the myeloablative chemotherapy and release pro-inflammatory cytokines andantigen-presenting cells(APCs) which then trigger donor T-cell activation and proliferation leading to GVHD.2[Figure 1]

Fig 1

Acute GVHD normally occurs within 100 days of HSCT and affect mainly the skin, liver and gastrointestinal (GI) tract. Approximately 50% of patients respond to front-line therapy using steroids along with continued calcineurin inhibitors. For those who failed to respond to steroids, there is no viable second-line therapy. Treatments such as  azathioprine, mycophenolate mofetil (MMF), sirolimus, extracorporeal photopheresis (ECP), imatinib, methotrexate (MTX), and TNF-alpha inhibitors have all yielded low efficacy.1,2Intense immunosuppression may also result in higher risk of cancer relapse.

Mesenchymal Stem Cells (MSCs)

Mesenchymal stem cells (MSCs) have emerged as a therapeutic potential in regenerative medicine, because of their unique properties of tissue repair. MSCs lack major histocompatibility complex (MHC-II) expression which renders them immune-privileged without risk of rejection or reaction in unrelated and unmatched recipients.3Hence, MSCs may be obtained from an unrelated donor, cultured, stored and injected into a patient with minimal delay. Because MSCs also possess potent immunoregulatory functions and ability to home in to the sites of injury, there has been increasing interest in the role of MSCs in autoimmune diseases, and inflammatory diseases, and more specifically in allogeneic HSCT, especially in the treatment of GVHD. 4-6

Mesenchymal stem cells were originally discovered in the bone marrow stroma but have since been demonstrated in many other tissues in the body. Probably the best source of MSC is located in the mucoid connective tissue known as Wharton’s jelly in the umbilical cord of the newborn child in whom the MSCs have the longest telomere lengths and share certain embryonic cell-like qualities.7Compared to bone marrow-derived and adipose-derived MSCs, UC-MSCs express most of the stem cells/ pluripotent markers at higher level which indicates a higher degree of stemness and self-renewal capacity. UC-MSCs also have short population doubling time during culturing, minimal senescence and no chromosomal abnormalities or expression of tumour oncogenes while still maintaining the differential potential until the late passages. Studies showed that UC-MSCs derived from Wharton’s jelly do not transform into tumor-associated fibroblasts in the presence of breast and ovarian cancer cells could inhibit cancer cell growth in vivo and in vitro.8

At Cytopeutics, we go further to determine the medical history of three generations including the donor’s siblings, donor’s parents and grandparents and exclude potential donors with a personal or family pedigree of cancer, infections, genetic and chromosomal disorders, cardiovascular and other familial diseases. The MSCs are also screened for possible genetic mutations and genetic alterations before and after culture.

Immunomodulatory Properties of MSCs

One of the most remarkable and unforeseen aspects of MSCs pertains to their immunomodulatory activity.4,5MSCs inhibit T-cell activation and proliferation, including activated CD4+ (helper) and CD8+ (cytotoxic) T-cells which are crucial in in the actication of GVHD and autoimmune diseases. MSCs also inhibit dendritic cell (DC) differentiation, B cell proliferation, natural killer (NK) cell activity and  switch the cytokine secretion profiles of these cells, from a pro-inflammatory Th1 profile to an anti-inflammatory Th2 cytokine profile.  In addition, MSCs directly secrete a vast array of anti-inflammatory immunomodulatory soluble mediators such as interleukin-10 and prostaglandin E2. [Figure 2].

MSCs for aGVHD

Allogeneic MSCs were first administered by Le Blanc et al. in 2004 to a child with steroid refractory acute GVHD who then showed complete resolution of GVHD.9Numerous clinical trials have been carried out since then using allogenic MSCs from various sources as a salvage therapy among steroid refractory acute GVHD patients.6-13The outcomes of these studies generally demonstrated that MSCs therapy has good tolerability and not associated with long-term risk. More than 50% of the GVHD patients had complete response with no adverse events from the MSC treatment with high 50 to 80% survival rate. In one clinical study comparing UC-MSCs with bone marrow-derived-MSCs, UC-MSCs had superior proliferative potential and more suppressive effects on T-cell proliferation when infused at a mean cell dosage between 4.1 x 106and 6.17 x 106cells/kg body weight of patient. Indeed the study showed the manifestations of aGVHD improved dramatically without additional second-line immunosuppressive therapies.10

Allogeneic MSC therapy has been approved in Canada and New Zealand as a treatment for steroid-resistant refractory aGVHD in children, for both adults and children in Japan.14

Objectives and Design of the present Cyto-MSC study

So far MSCs have been investigated mostly as salvage treatment for steroid refractory aGVHD after exhausting other immunosuppressive options. Use of UC-MSCs concurrently with steroids as front-line therapy for aGVHD have not been explored. We hypothesise that this strategy will further improve survival and reduce mortality and morbidity, given that treatment response to steroids is slow and far from satisfactory and comes with other complications such as sepsis, including viral reactivation and fungal infection.

This is an investigator-initiated study headed by Dr Tan Sen Mui, senior consultant haematologist at Ampang Hospital. Cytopeutics is a pioneer in stem cell research and treatment. Operating out of Cyberjaya with its contracted GMP-certified laboratory in a purpose-built facility. Cytopeutics is honored to be collaborating with senior doctors, hospitals and universities, both private and public, locally on basic, translational and clinical research in numerous conditions.

To determine the efficacy and safety of allogeneic infusion of Cytopeutics umbilical cord-derived mesenchymal stem cells (Cyto-MSC) in combination of standard corticosteroid therapy as front-line approach for treatment of grade II-IV acute GVHD patients, we designed a randomized-controlled double-blind phase I/II clinical trial involving grade II-IV acute GVHD patients. The subjects are patients who had developed grade II-IV aGVHD following allogeneic HSCT (MRD/ MUD/ Unrelated Cord/ Haploidentical) for malignant or non-malignant haematological disorders. 40 consecutive eligible patients will be recruited in this study. An independent Data Safety Monitoring Board (DSMB) will be appointed among medical experts to monitor and evaluate the patient’s safety and progress throughout the study in what is expected to be a Malaysia-led initiative to treat a critical and common condition.


References

  1. Pavletic SZ, Martin P, Lee SJ, et al.,. Measuring therapeutic response in chronic graft-versus-host disease: National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IV. Response Criteria Working Group report. Biol Blood Marrow Transplant. 2006;12(3):252-66.
  2. Blazar BR, Murphy WJ, Abedi M. Advances in graft versus host disease biology and therapy. Nature Rev Imm. 2012;12:443-58.
  3. Ryan JM, Barry FP, Murphy JM, Mahon BP. Mesenchymal stem cells avoid allogeneic rejection. Journal of Inflammation. 2005;2:8.
  4. Stagg J, Galipeau J. Mechanisms of immune modulation by mesenchymal stromal cells and clinical translation. Current molecular medicine. 2013;13(5):856-67.
  5. Yagi H, Soto-Gutierrez A, Parekkadan B,et al.,. Mesenchymal stem cells: mechanisms of immunomodulation and homing. Cell transplantation. 2010;19(6):667-79.
  6. Amorin B, Alegretti AP, Valim V,et al.,. Mesenchymal stem cell therapy and acute graft-versus-host disease: a review. Human cell. 2014;27(4):137-50.
  7. McGuckin CP, Forraz N, Baradez MO, et al.,. Production of stem cells with embryonic characteristics from human umbilical cord blood. Cell Prolif. 2005;38(4):245-55.
  8. Subramanian A, Shu-Uin G, Kae-Siang N, et al.,. Human umbilical cord Wharton’s jelly mesenchymal stem cells do not transform to tumor-associated fibroblasts in the presence of breast and ovarian cancer cells. J Cell Biochem. 2012;113(6):1886-95.
  9. Le Blanc K, Rasmusson I, Sundberg B,. et al.,. Treatment of severe acute graft-versus-host disease with third party haploidentical mesenchymal stem cells. Lancet. 2004;363(9419):1439-41.
  10. Wu KH, Chan CK, Tsai C, et al.,. Effective treatment of severe steroid-resistant acute graft-versus-host disease with umbilical cord-derived mesenchymal stem cells. Transplantation. 2011;91(12):1412-6.
  11. Le Blanc K, Frassoni F, Ball L, et al.,. Mesenchymal stem cells for treatment of steroid-resistant, severe, acute graft-versus-host disease: a phase II study. Lancet. 2008;371(9624):1579-86.
  12. Introna M, Lucchini G, Dander E, et al.,. Treatment of graft versus host disease with mesenchymal stromal cells: a phase I study on 40 adult and pediatric patients. Biol Blood Marrow Transplant. 2014;20(3):375-81.
  13. Gao L, Zhang YQ, Hu BY, et al.,. Phase II Multicenter, Randomized, Double-Blind Controlled Study of Efficacy and Safety of Umbilical Cord–Derived Mesenchymal Stromal Cells in the Prophylaxis of Chronic Graft-Versus-Host Disease After HLA-Haploidentical Stem-Cell Transplantation. J Clin Oncol. 2016;34(24):2843-50
  14. Yoshioka, S., and Y. Miura. “Human Mesenchymal Stem Cell Therapy for Acute Graft Versus Host Disease.” Transl Med (Sunnyvale)6, no. 171 (2016): 2161-1025.

About the author
Dr Chin Sze Piaw is a clinical and research advisor for Cytopeutics and co-investigator in the Cyto-MSC acute GVHD study.