Granulocyte-Colony Stimulating Factor Therapy to Induce Neovascularization in Ischemic Heart Disease
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DOCTOR OF MEDICAL SCIENCE DANISH MEDICAL JOURNAL Granulocyte-Colony Stimulating Factor Therapy to Induce Neovascularization in Ischemic Heart Disease Rasmus Sejersten Ripa VI. Ripa RS, Nilsson JC, Wang Y, Søndergaard L, Jørgensen E, Kastrup J. Short- and Long-Term Changes in Myocardial Function, Morphology, Edema and Infarct Mass Following ST- This review has been accepted as a thesis together with 7 previously published papers by University of Copenhagen August 1st 2011 and defended on November Segment Elevation Myocardial Infarction Evaluated by Serial 30th 2011 Magnetic Resonance Imaging. Am Heart J 2007;154:929-36. VII. Lyngbæk S, Ripa RS, Haack-Sørensen M, Cortsen A, Kragh L, Official opponents: Erling Falk and Hans Erik Bøtker Andersen CB, Jørgensen E, Kjær A, Kastrup J, Hesse B. Serial Correspondence: Department of Cardiology, Rigshospitalet, Blegdamsvej 9, DK-2100 in vivo Imaging of the Porcine Heart After Percutaneous, 111 Copenhagen Ø, Denmark Intramyocardially Injected Indium-Labeled Human Mesen- chymal Stromal Cells. Int J Cardiovasc Imaging 2010; 26:273- E-mail: [email protected] 84. Dan Med J 2012;59(3):B4411 1. BACKGROUND AND AIM The concept of adult stem cells within the bone marrow was This dissertation is based on the following original publications. introduced in 1960 by identification of cells capable of reconsti- These publications are referred to by their roman numerals in tuting hematopoiesis in mice. (1) Asahara et al (2,3) extended this the text: concept almost 40 years later by showing that bone marrow- I. Ripa RS, Wang Y, Jørgensen E, Johnsen HE, Hesse B, Kastrup derived circulating endothelial progenitor cells incorporated into J. Intramyocardial Injection of Vascular Endothelial Growth sites of angiogenesis in animal models of ischemia. In 2001, Orlic Factor-A165 Plasmid Followed by Granulocyte-Colony Stimu- et al (4) published a ground-breaking but also very controversial lating Factor to Induce Angiogenesis in Patients with Severe (5,6) trial challenging the paradigm of the heart as a post-mitotic Chronic Ischemic Heart Disease. Eur Heart J 2006;27:1785- organ thereby igniting the notion of cardiac regeneration. In the 92. following decade an increasing number of animal and small clini- II. Ripa RS, Wang Y, Goetze JP, Jørgensen E, Johnsen HE, Tägil K, cal studies have indicated an effect of cell based therapies for Hesse B, Kastrup J. Circulating Angiogenic Cytokines and ischemic heart disease. Stem Cells in Patients with Severe Chronic Ischemic Heart Disease – Indicators of Myocardial Ischemic Burden? Int J ISCHEMIC HEART DISEASE Cardiol 2007;120:181-187. Ischemic heart disease is caused by a pathological mismatch III. Ripa RS, Jørgensen E, Baldazzi F, Frikke-Schmidt R, Wang Y, between the supply to and demand for oxygen in the left ven- Tybjærg-Hansen A, Kastrup J. The Influence of Genotype on tricle. The pathology is most commonly stenotic or obstructive Vascular Endothelial Growth Factor and Regulation of Myo- atherosclerotic disease of the epicardial coronary artery. The cardial Collateral Blood Flow in Patients with Acute and normal coronary circulation supplies the heart with sufficient Chronic Coronary Heart Disease. Scand J Clin Lab Invest oxygen to prevent underperfusion. This is accomplished by the 2009;69:722-728. ability of the coronary vasculary bed to rapid adaptation of the IV. Ripa RS, Jørgensen E, Wang Y, Thune JJ, Nilsson JC, Sønder- coronary blood flow by varying its resistance. gaard L, Johnsen HE, Køber L, Grande P, Kastrup J. Stem Cell An atherosclerotic stenosis increases epicardial resistance and Mobilization Induced by Subcutaneous Granulocyte-Colony thus limits appropriate increases in perfusion when the demand Stimulating Factor to Improve Cardiac Regeneration After for oxygen is augmented (e.g. during exercise). In severe stenosis, Acute ST-Elevation Myocardial Infarction. Result of the small changes in luminal diameter (e.g. by spasm or thrombi) can Double-Blind Randomized Placebo Controlled STEMMI Trial. produce significant hemodynamic effects and even reduce myo- Circulation 2006;113:1983-1992. cardial perfusion at rest. Myocardial ischemia can also occur with V. Ripa RS, Haack-Sørensen M, Wang Y, Jørgensen E, Morten- normal oxygen supply if myocardial demands are markedly in- sen S, Bindslev L, Friis T, Kastrup J. Bone Marrow-Derived creased by left ventricular hypertrophy or during exercise. Mesenchymal Cell Mobilization by Granulocyte-Colony Sti- The symptoms of myocardial ischemia range from silent mulating Factor after Acute Myocardial Infarction: Results ischemia to stable angina pectoris to unstable angina pectoris to from the Stem Cells in Myocardial Infarction (STEMMI) Trial. non-ST- and ST-segment elevation myocardial infarction (STEMI). Circulation 2007;116(11 Suppl):I24-30. Patients with STEMI or patients with moderate to severe but stable angina pectoris (Canadian Cardiovascular Society (CCS) DANISH MEDICAL JOURNAL 1 angina class II-IV) have been included into the majority of trials and route of administration may be insufficient in achieving op- with gene- or cell-therapy. The pathology in these two popula- timal concentration of the growth factor within the heart. The tions has many similarities but also some important differences. second hypothesis is supported by the short half-life of the admi- First, patients with STEMI (usually patients with previous nistered protein, but administration of a higher dose was not myocardial infarction are excluded) have a single, or occasionally possible due to dose-limiting toxicities resulting from systemic a few, severe ischemic events caused by one coronary occlusion exposure. whereas the patients with chronic ischemia suffer from intermit- Trials with growth factor gene therapy were then initiated to tent myocardial ischemia (often through years) usually caused by enhance myocardial expression for a sustained period of time and stenotic lesions in several coronary arteries. Second, patients with to minimize systemic effects. chronic ischemia typically have reversible ischemia not leading to myocardial necrosis, whereas patients with STEMI develop irre- Gene therapy versible myocardial damage. We thus have difference in the Gene therapy is introduction of genetic material into an organism therapeutic goals in the two patient populations. Patients with in order to obtain a therapeutic result by production of proteins. STEMI need new myocytes and vascular support for both new The advantages over protein therapy are primarily less systemic myocytes and for hibernating myocytes within the necrotic area, concentrations and prolonged period of expression. Some of the whereas patients with chronic ischemia primarily need improved pitfalls are to achieve optimal tissue expression and to prevent perfusion of the reversible ischemic area. This also affects the expression in other tissues. The gene needs a transfection vector endpoint assessment in the two populations. Patients with chron- to get into the cells; this can be viruses, liposome particles or ic ischemia will be expected to have no change or even a slow naked plasmids. (19) Naked plasmid is the most simple to use, but deterioration in heart function with their current anti-ischemic also a method with low transfection rate. treatment whereas patients after STEMI are expected to have a Several minor safety and efficacy trials using both the VEGF-A recovery in function due to recovery of hibernating myocardium and the FGF genes have been published. (20-25) Naked plasmid, following balloon angioplasty and coronary stenting. A significant liposomes, and viruses have been used as transfection vector, and placebo effect can be expected in both populations underscoring both intracoronary and intramyocardial (during thoracotomy or the need for a proper control group. percutaneously) administration has been used. Many early phase clinical trials of new therapies for patients The REVASC Trial (26) randomized 67 patients with severe an- with ischemic heart disease have safety as primary endpoint and gina pectoris and coronary artery disease to intramyocardial efficacy as secondary exploratory endpoint. These early trials are AdVEGF-A121 gene transfer (N=32) or continued maximum medi- often without control-groups or with non-blinded, non-placebo cal therapy (N=35). The treatment was open-label, and the con- treated controls. This warrants for extreme caution in data inter- trol group did not receive placebo treatment. The primary end- pretation since both a significant placebo effect as well as a signif- point of change in time to ST-segment depression on exercise ECG icant change due to ‘the natural course’ must be accounted for. after 12 weeks was not statistically significant compared to con- trols. Several secondary endpoints including exercise test at 26 BIOLOGICAL INTERVENTION IN MYOCARDIAL REGENERATIVE weeks, and CCS angina class did reach a statistical significant MEDICINE difference. (26) Based on our pathogenetic understanding, previous trials of Our group initiated a multicenter, randomized, double-blind, biological intervention in myocardial regeneration can roughly be and placebo controlled trial of plasmid VEGF-A165 gene therapy in divided into three main groups, vascular growth factor proteins, patients with stable severe angina pectoris (The Euroinject One genes encoding vascular growth factors, and stem/progenitor cell Trial). (27-29) Intramyocardial injections of the plasmids or place- therapy. Only a few trials have combined these modalities. bo