Clinical Trials

The CTP has been involved in cell-based clinical trials for both anti-cancer therapies and for regenerative medicine. To-date the program has manufactured cellular products for four trials: 1) A Phase I study of autologous bone marrow transplantation with stem cell gene markeing in multiple myeloma; 2) A Dose Escalation Study of NK-92 Cell Infusions in Patients with Hematological Malignancies in Relapse After Autologous Stem Cell Transplantation; 3) A Phase I Trial Evaluating the Administration of Epstein Barr Virus (EBV)-Specific Cytotoxic T-Lymphocytes (CTLs) to Patients with Recurrent or Metastatic EBV-Positive Nasopharygneal Cancer (NPC), and 4) A Single Center, Phase I Clinical Trial to Establish the Safety of Autologous Cell-Based Gene Transfer of Human eNOS (heNOS) in Patients with Refractory Pulmonary Arterial Hypertension (PAH) that have Failed Conventional Treatments.

1) A Phase I study of the transplantation of genetically marked autologous bone marrow stromal cells for delayed engraftment patients

Mesenchymal stromal cells (MSCs) have been shown to support hematopoiesis and support graft engraftment. In this study, the safety and feasibility of infusing genetically modified autologous MSCs into three patients with delayed marrow engraftment after autologous hematopoietic cell transplantation for hematologic malignancies was investigated.

In this study, three patients received intravenous infusion of culture-expanded autologous MSCs electrotransfectd with a plasmid DNA carrying a marker gene and human Factor IX cDNA without further conditioning 49-210 days after the autotransplant. There was no toxicity associated with the MSC infusions, and all patients were in remission 5-6 years post-infusion with normal blood counts. Engraftment of MSCs was documented in the marrow of recipients up to 8 months post infusion by PCR for neor and for unique FIX sequeces.

2) Dose Escalation Study of NK-92 Cell Infusions in Patients with Hematological Malignancies in Relapse After Autologous Stem Cell Transplantation

Natural killer (NK) cells represent roughly 15% of all lymphocytes, have strong anti-tumor properties and the ability to kill a broad spectrum of cancer cells. An allogenic cell line, the NK-92 cell line was isolated in 1992 from a patient with large granular lymphoma (Gong JH et al, 1994), and is easy to scale-up, is highly cytotoxic and does not require systemic administration of cytokines, making it ideally suited for immunotherapy purposes. In our study we treated patients with hematological malignancies in relapse after autologous stem cell transplantation. The NK-92 cell line can be cultured and expanded under GMP condition making them suitable for administration to patients and available essentially on demand. Eight patients have received repeated cycles of NK-92 infusions, and have exhibited promising outcomes, including one patient with a clinical response. There have no study-related adverse events to-date.

The cost of manufacturing 5e9 cells/m2/infusion is extremely high, and has limited our ability to treat patients. We have temporarily halted our clinical trial as we seek to address this problem by optimizing our manufacturing processes to improve cell yield and reduce production costs, while seeking additional funding.

3) A Phase I Trial Evaluating the Administration of Epstein Barr Virus (EBV)-Specific Cytotoxic T-Lymphocytes (CTLs) to Patients with Recurrent or Metastatic EBV-Positive Nasopharygneal Cancer (NPC)

Nasopharyngeal carcinoma (NPC) is a malignant disease with a variable range of incidence depending on age, geographical location, race, and Epstein Barr virus (EBV) exposure. It has an annual incidence of nearly 1 case per 100,000 children under the age of 21, and 0.5 cases per 100,000 adults in the USA (Niedobitek et al., 2000 and Zubizarreta et al., 2000).

In our study, autologous cells were prepared using a multi-step process, in which EBV-infected antigen presenting cells were first generated, and then used to stimulate patient T-cells from their peripheral blood to generate EBV-specific cytotoxic T-lymphocytes (CTLs). A majority (>98%) of EBV-specific CTLs were CD3+ T cells, with less than 5% being positive for CD16 or CD19. EBV-specific CTLs showed significant heterogeneity in the expression of other markers. EBV-specific CTLs demonstrated extensive killing of autologous EBV-infected LCLs, minimal killing of HLA antigen mismatched LCLs, and the absence of non-specific killing.

Our protocol was modified from the clinical study executed at the Baylor College of Medicine in Houston, Texas. Five patients have been treated overall, four at 5x107/m2and one at the 1x108/m2; there was no safety concerns reported. This trial has also been halted due to insufficient funding.

4) A Single Center, Phase I Clinical Trial to Establish the Safety of Autologous Cell-Based Gene Transfer of Human eNOS (heNOS) in Patients with Refractory Pulmonary Arterial Hypertension (PAH) that have Failed Conventional Treatments

Pulmonary Aterial Hypertension (PAH) is a progressive disease which in its most severe forms has a prognosis that is as poor as many malignancies. Although there have been a number of advances in the therapy of PAH, most patients untilmately fail all available treatment and require lung transplantation as a final resort. However, only a minority of patients ultimately receive transplants, and this procedure is associated with significant morbidity due to chronic rejection, such that the 5-year survival is less than 50%. Thus there is an unmet need for new therapies of PAH that can restore the pulmonary vascular structure and function.

In this study, the industry sponsors choose to harvest endothelial progenitor cells (EPCs) from the patients blood by apheresis, culture expand them in our GMP-grade Orsino Facility for Cell Therapy, electroporate them with human endothelial nitric oxide synthase (heNOS) and re-introduce the genetically engineered cells into pulmonary circulation through central venous injection. Pre-clinical studies have shown that EPCs infused in this manner are filtered by the lung and lodge at the level of pre-capillary arteriole and help restore the continuity of pulmonary microcirculation. Pre-clinical studies have also demonstrated that gene transfer of heNOS is effective in preventing PAH induced by plant alkaloids in rats.

The Orsino Facility for Cell Therapy has manufactured clinical grade EPCs, transfected with heNOS as per standard operating procedures for three patients. Based on the initial success of this protocol, the sponsors are currently planning a larger Phase II study, and are also considering initiating a Phase I study using heNOS transfected EPCS for treatment of acute myocardial infarction (ENACT-AMI).

Proposed Studies

1) IMPlantation of Autologous CD133+ stem cells in patients undergoing Cornary Artery Bypass Graft (CABG) Surgery trial

Coronary artery bypass grafting (CABG) is the optimal approach to obtain complete coronary revascularization in patients with severe chronic ischemic cardiomyopathy and left ventricular dysfunction one of the most frequently performed surgical procedures, and is associated with improved survival, reduced angina and increased exercise tolerance. CD133+ are a well characterized, primitive group of stem cells that possess high angiogenic capacity and appear to be useful for cardiac repair in the acutely infarcted and chronically ischemic myocardium by inducing neovascularization, inhibiting apoptosis and improving cardiac function. Previous clinical trials have reported beneficial effects by combining intra-myocardial injection of CD133+ and conventional CABG, but their studies were not adequately blinded, and lacked a proper control groups.

In this study, Dr. Terrence Yau and Dr. Richard Weisel from the Toronto General Hospital will evaluate the safety and preliminary safety of autologous CD133+ bone marrow cells processed using the CliniMACS® CD133 Reagent System using a randomized, double blinded, placebo-controlled study design. 20 Patients will be followed for 18 month-period. Safety will be assessed as freedom from a Major Adverse Cardiac Event (MACE) defined as cardiac death, myocardial infarction or repeat coronary bypass grafting/percutaneous intervention, and freedom from any major arrhythmias. Efficacy will be assessed by relief of symptom severity, improved quality of life (6 months) and by low-dose dobutamine echocardiography and MRI scans. Results from this study will be pooled from the 20-patient IMPACT-CABG study currently being led by Dr. Nicolas Noiseux, Department of Cardiac Surgery Hôtel-Dieu and Centre Hospitalier de l'Université de Montréal (CHUM) to power efficacy analysis.

The Cell Therapy Program has developed the manufacturing, quality and regulatory strategy for implementation of this clinical protocol. We have pioneered new Standard Operating Procedures (SOPs) to manufacture clinical-grade CD133+ cells in the operating room (OR) itself. The Cell Therapy Program is also responsible for the quality assurance of the in-process and final product. We are in the process of obtaining regulatory approval from Health Canada for this protocol.

2) A Multi-Centre Non-Randomized, Non-Blinded, Open-Label, Dose Escalation Phase I Clinical Trial Evaluating Human Mesenchymal Stromal Cells for the Treatment of Early Stage Osteonecrosis of the Hip; a Phase I dose-escalation study

In collaboration with Dr. Andrew Howard and Dr. Ben Alman at the Hospital for Sick Children, we are planning on embarking on a study to treat pediatric patients with avascular necrosis in patients with acute lymphoblastic leukemia, trauma at the hip joint, and sickle cell disease. There is no good treatment of hip AVN in the pediatric population. Conventional core decompression of the femoral head with bone grafts have failed in modifying the progression of the disease. In most instances, patients progress to develop advanced arthritis and eventually require hip arthroplasty.

We will embark on a phase I clinical study in a similar study design using 3 cohorts of 3 patients with autologous MSCs in doses of 2 x 106-1 x108 cells; the MSCs will be injected into the decompressed and debrided femoral head.

Patients will be followed for two years to evaluate safety and preliminary efficacy, including disease progression to osteoarthritis and hip replacement. The protocol is in the pre-pre CTA consultation stages with Health Canada, and in the scale-up stages from a manufacturing perspective. The study will be open in the Fall of 2011.