Allogeneic Cardiosphere-derived Cells Research Articles

Effects of Cardiac Stem Cell on Postinfarction Arrhythmogenic Substrate.

Clinical data suggest that cardiosphere-derived cells (CDCs) could modify post-infarction scar and ventricular remodeling and reduce the incidence of ventricular tachycardia (VT). This paper assesses the effect of CDCs on VT substrate in a pig model of postinfarction monomorphic VT. We studied the effect of CDCs on the electrophysiological properties and histological structure of dense scar and heterogeneous tissue (HT). Optical mapping and histological evaluation were performed 16 weeks after the induction of a myocardial infarction by transient occlusion of the left anterior descending (LAD) artery in 21 pigs. Four weeks after LAD occlusion, pigs were randomized to receive intracoronary plus trans-myocardial CDCs (IC+TM group, n: 10) or to a control group. Optical mapping (OM) showed an action potential duration (APD) gradient between HT and normal tissue in both groups. CDCs increased conduction velocity (53 ± 5 vs. 45 ± 6 cm/s, p < 0.01), prolonged APD (280 ± 30 ms vs. 220 ± 40 ms, p < 0.01) and decreased APD dispersion in the HT. During OM, a VT was induced in one and seven of the IC+TM and control hearts (p = 0.03), respectively; five of these VTs had their critical isthmus located in intra-scar HT found adjacent to the coronary arteries. Histological evaluation of HT revealed less fibrosis (p < 0.01), lower density of myofibroblasts (p = 0.001), and higher density of connexin-43 in the IC+TM group. Scar and left ventricular volumes did not show differences between groups. Allogeneic CDCs early after myocardial infarction can modify the structure and electrophysiology of post-infarction scar. These findings pave the way for novel therapeutic properties of CDCs.

Strategies for Bottlenecks of rAAV-Mediated Expression in Skeletal and Cardiac Muscle of Duchenne Muscular Dystrophy.

Gene therapy using the adeno-associated virus (rAAV) to deliver mini/micro- dystrophin is the current promising strategy for Duchenne Muscular Dystrophy (DMD). However, the further transformation of this strategy still faces many "bottlenecks". Most gene therapies are only suitable for infants with strong muscle cell regeneration and immature immune system, and the treatment depends heavily on the high dose of rAAV. However, high-dose rAAV inevitably causes side effects such as immune response and acute liver toxicity. Therefore, how to reduce the degree of fibrosis and excessive immune response in older patients and uncouple the dependence association between therapeutic effect and high dose rAAV are crucial steps for the transformation of rAAV-based gene therapy. The article analyzes the latest research and finds that the application of utrophin, the homologous protein of dystrophin, could avoid the immune response associated with dystrophin, and the exploration of methods to improve the expression level of mini/micro-utrophin in striated muscle, combined with the novel MyoAAV with high efficiency and specific infection of striated muscle, is expected to achieve the same therapeutic efficacy under the condition of reducing the dose of rAAV. Furthermore, the delivery of allogeneic cardio sphere-derived cells (CDCs) with anti-inflammatory and anti-fibrotic characteristics combined with immune suppression can provide a continuous and appropriate "window period" for gene therapy. This strategy can expand the number of patients who could benefit from gene therapy.

Repeated intravenous cardiosphere-derived cell therapy in late-stage Duchenne muscular dystrophy (HOPE-2): a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial

Cardiosphere-derived cells (CDCs) ameliorate skeletal and cardiac muscle deterioration in experimental models of Duchenne muscular dystrophy. The HOPE-2 trial examined the safety and efficacy of sequential intravenous infusions of human allogeneic CDCs in late-stage Duchenne muscular dystrophy. In this multicentre, randomised, double-blind, placebo-controlled, phase 2 trial, patients with Duchenne muscular dystrophy, aged 10 years or older with moderate upper limb impairment, were enrolled at seven centres in the USA. Patients were randomly assigned (1:1) using stratified permuted blocks to receive CAP-1002 (1·5 × 108 CDCs) or placebo intravenously every 3 months for a total of four infusions. Clinicians, caregivers, patients, and clinical operations personnel were fully masked to treatment groups. The primary outcome was the change in mid-level elbow Performance of Upper Limb version 1.2 (PUL 1.2) score at 12 months, assessed in the intention-to-treat population. Safety was assessed in all individuals who received an investigational product. This trial is registered with ClinicalTrials.gov, NCT03406780. Between March 1, 2018, and March 31, 2020, 26 male patients with Duchenne muscular dystrophy were enrolled, of whom eight were randomly assigned to the CAP-1002 group and 12 to the placebo group (six were not randomised due to screening failure). In patients who had a post-treatment PUL 1.2 assessment (eight in the CAP-1002 group and 11 in the placebo group), the mean 12-month change from baseline in mid-level elbow PUL1.2 favoured CAP-1002 over placebo (percentile difference 36·2, 95% CI 12·7-59·7; difference of 2·6 points; p=0·014). Infusion-related hypersensitivity reactions without long-term sequelae were observed in three patients, with one patient discontinuing therapy due to a severe allergic reaction. No other major adverse reactions were noted, and no deaths occurred. CAP-1002 cell therapy appears to be safe and effective in reducing deterioration of upper limb function in patients with late-stage Duchenne muscular dystrophy. Various measures of cardiac function and structure were also improved in the CAP-1002 group compared with the placebo group. Longer-term extension studies are needed to confirm the therapeutic durability and safety of CAP-1002 beyond 12 months for the treatment of skeletal myopathy and cardiomyopathy in Duchenne muscular dystrophy. Capricor Therapeutics.

Effect of cardiosphere-derived cells on segmental myocardial function after myocardial infarction: ALLSTAR randomised clinical trial

BackgroundMost cell therapy trials failed to show an improvement in global left ventricular (LV) function measures after myocardial infarction (MI). Myocardial segments are heterogeneously impacted by MI. Global LV function...

Abstract 12730: Cardiosphere-derived Cells Improve Segmental Myocardial Circumferential Strain by Magnetic Resonance Imaging: Results From the Allogeneic Heart Stem Cells to Achieve Myocardial Regeneration Study

Introduction: Cell therapy failed to improve global LV ejection fraction (LVEF) in most trials of post-MI LV dysfunction. LVEF does not consider the effect of cell therapy on different segments of the myocardium, which may be heterogeneous across different myocardial regions in patients with regional MI. Hypothesis: Allogeneic cardiosphere-derived cells (CDCs) improve segmental (but not global) myocardial function indexed as circumferential strain by MRI. Methods: In this randomized double-blind trial, 142 post-MI patients with LVEF&lt;45% and 15% or greater LV scar size were randomized in 2:1 ratio to receive intracoronary infusion of allogenic CDCs or placebo, respectively. Change in segmental myocardial circumferential strain (Ecc) by MRI from baseline to 6-month was compared between CDCs and placebo groups. Results: In total, 124 patients completed the 6-month follow-up (mean (SD) age 54.3(10.8) and 108 (87.1%) males). Segmental Ecc improvement was significantly greater in patients receiving CDC (-0.5%(4.0)) compared to placebo (0.2%(3.7), p=0.05). The greatest benefit for improvement in segmental Ecc was observed in segments containing scar tissue (change in segmental Ecc of -0.7% (3.5) in patients receiving CDC vs. 0.04% (3.7) in the placebo group, p=0.04). The beneficial effect of CDCs for improving segmental Ecc was greater in patients with LV ejection fraction&lt;41%, LV scar size&gt;18.8% or LV end-diastolic volume index&gt;100 [mixed effect regression coefficients of -0.92(p=0.02),-0.78(p=0.03), and -1.16(p=0.004) respectively versus -0.58(p=0.05) for the entire cohort]. Conclusions: In patients with post-MI LV dysfunction, allogeneic CDC administration resulted in improved segmental myocardial function. This CDC induced improvement in segmental myocardial function was greater in patients with severe LV dysfunction, dilated LV and greater infarct size. (clinicaltrials.gov Identifier: NCT01458405).

Intracoronary Administration of Allogeneic Cardiosphere-Derived Cells Immediately Prior to Reperfusion in Pigs With Acute Myocardial Infarction Reduces Infarct Size and Attenuates Adverse Cardiac Remodeling.

Allogeneic cardiosphere-derived cells (CDCs) exert cardioprotective effects when administered intracoronarily after reperfusion in animal models of acute myocardial infarction (AMI). The "no-reflow" phenomenon develops rapidly post-reperfusion and may undermine the efficacy of cell therapy, due to poor cell delivery in areas of microvascular obstruction (MVO). We hypothesized that CDC-induced cardioprotection would be enhanced by cell administration prior to reperfusion, when microvasculature is still relatively intact, to facilitate widespread cell delivery within the ischemic area. We studied 81 farm pigs; 55 completed the specified protocols. A dose-optimization study in infarcted pigs demonstrated that the doses of 5 million and 10 million CDCs are the maximum safe doses that can be administered intracoronarily at 5 minutes prior to and at 5 minutes post-reperfusion, respectively, without aggravating MVO. Quantification of acute cell retention by polymerase chain reaction demonstrated that cell delivery prior to reperfusion resulted in higher cardiac cell retention compared to delivery post-reperfusion. We then performed a randomized, placebo-controlled study to assess the long-term efficacy of intracoronary infusion of 5 million allogeneic CDCs, delivered at 5 minutes prior to reperfusion, in a porcine model of AMI. The CDC therapy resulted in decreased scar size, improved regional systolic function, and attenuation of adverse cardiac remodeling (manifested as preserved global systolic function, preserved end-systolic volume, and decreased interstitial fibrosis) compared to placebo at 30 days post-MI. Dose-optimized intracoronary infusion of allogeneic CDCs prior to reperfusion in a porcine model of AMI is feasible, safe and confers long-term benefits.

Allogeneic cardiosphere-derived cells for the treatment of heart failure with reduced ejection fraction: the Dilated cardiomYopathy iNtervention with Allogeneic MyocardIally-regenerative Cells (DYNAMIC) trial.

The DYNAMIC trial assessed the safety and explored the efficacy of multivessel intracoronary infusion of allogeneic cardiosphere-derived cells (CDCs) in patients with heart failure and reduced ejection fraction (HFrEF). Here we report the results of the DYNAMIC trial. We enrolled 14 patients with EF ≤35% and NYHA Class III-IV despite maximal medical and device-based therapy in this single-centre, open-label trial. Intracoronary catheterisation delivered four escalating doses (totalling 37.5-75 million cells) by sequential non-occlusive technique to all three major coronary arteries. The primary safety endpoint was a composite of post-infusion TIMI flow, ventricular tachycardia/fibrillation, sudden death, major adverse cardiac events or acute myocarditis within 72 hours. Twelve patients were male and EF averaged 23.0% (±4.5%). No primary safety endpoints were observed. Two patients died of HFrEF progression nine and 12 months following infusion. Compared to baseline, there was an improvement in EF (26.8% vs 22.9%, p=0.023) and left ventricular end-systolic volume (139.5 vs 177.8 cm3, p=0.03) at six months. Quality of life (QoL) scores and NYHA class (p=0.006) improved at six months. At 12 months, the improvement in EF and QoL remained significant. Global intracoronary infusion of allogeneic CDCs is safe and feasible. The efficacy of allogeneic CDCs in HFrEF needs to be tested in larger randomised trials.

Allogeneic cardiosphere-derived cells (CAP-1002) in critically ill COVID-19 patients: compassionate-use case series

There are no definitive therapies for patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Therefore, new therapeutic strategies are needed to improve clinical outcomes, particularly in patients with severe disease. This case series explores the safety and effectiveness of intravenous allogeneic cardiosphere-derived cells (CDCs), formulated as CAP-1002, in critically ill patients with confirmed coronavirus disease 2019 (COVID-19). Adverse reactions to CAP-1002, clinical status on the World Health Organization (WHO) ordinal scale, and changes in pro-inflammatory biomarkers and leukocyte counts were analyzed. All patients (n = 6; age range 19–75 years, 1 female) required ventilatory support (invasive mechanical ventilation, n = 5) with PaO2/FiO2 ranging from 69 to 198. No adverse events related to CAP-1002 administration were observed. Four patients (67%) were weaned from respiratory support and discharged from the hospital. One patient remains mechanically ventilated as of April 28th, 2020; all survive. A contemporaneous control group of critically ill COVID-19 patients (n = 34) at our institution showed 18% overall mortality at a similar stage of hospitalization. Ferritin was elevated in all patients at baseline (range of all patients 605.43–2991.52 ng/ml) and decreased in 5/6 patients (range of all patients 252.89–1029.90 ng/ml). Absolute lymphocyte counts were low in 5/6 patients at baseline (range 0.26–0.82 × 103/µl) but had increased in three of these five patients at last follow-up (range 0.23–1.02 × 103/µl). In this series of six critically ill COVID-19 patients, intravenous infusion of CAP-1002 was well tolerated and associated with resolution of critical illness in 4 patients. This series demonstrates the apparent safety of CAP-1002 in COVID-19. While this initial experience is promising, efficacy will need to be further assessed in a randomized controlled trial.

Nonocclusive multivessel intracoronary infusion of allogeneic cardiosphere-derived cells early after reperfusion prevents remote zone myocyte loss and improves global left ventricular function in swine with myocardial infarction.

Intracoronary cardiosphere-derived cells (icCDCs) infused into the infarct-related artery reduce scar volume but do not improve left ventricular (LV) ejection fraction (LVEF). We tested the hypothesis that this reflects the inability of regional delivery to prevent myocyte death or promote myocyte proliferation in viable myocardium remote from the infarct. Swine (n = 23) pretreated with oral cyclosporine (200 mg/day) underwent a 1-h left anterior descending coronary artery (LAD) occlusion, which reduced LVEF from 61.6 ± 1.0 to 45.3 ± 1.5% 30 min after reperfusion. At that time, animals received global infusion of allogeneic icCDCs (n = 8), regional infusion of icCDCs restricted to the LAD using the stop-flow technique (n = 8), or vehicle (n = 7). After 1 mo, global icCDCs increased LVEF from 44.8 ± 1.9 to 60.8 ± 3.8% (P < 0.05) with no significant change after LAD stop-flow icCDCs (44.8 ± 3.6 to 50.9 ± 3.1%) or vehicle (46.5 ± 2.5 to 47.7 ± 2.6%). In contrast, global icCDCs did not alter infarct volume (%LV mass) assessed at 2 days (11.2 ± 2.3 vs. 12.6 ± 2.3%), whereas it was reduced after LAD stop-flow icCDCs (7.1 ± 1.1%, P < 0.05). Histopathological analysis of remote myocardium after global icCDCs demonstrated a significant increase in myocyte proliferation (147 ± 32 vs. 14 ± 10 nuclei/106 myocytes, P < 0.05) and a reduction in myocyte apoptosis (15 ± 9 vs. 46 ± 10 nuclei/106 myocytes, P < 0.05) that increased myocyte nuclear density (1,264 ± 39 vs. 1,157 ± 33 nuclei/mm2, P < 0.05) and decreased myocyte diameter (13.2 ± 0.2 vs. 14.5 ± 0.3 μm, P < 0.05) compared with vehicle-treated controls. In contrast, remote zone changes after regional LAD icCDCs were no different from vehicle. These data indicate that changes in global LVEF after icCDCs are dependent upon preventing myocyte loss and hypertrophy in myocardium remote from the infarct. These arise from stimulating myocyte proliferation and reducing myocyte apoptosis indicating the importance of directing cell therapy to viable remote regions.NEW & NOTEWORTHY Administration of allogeneic cardiosphere-derived cells to the entire heart via global intracoronary infusion shortly after myocardial infarction favorably influenced left ventricular ejection fraction by preventing myocyte death and promoting myocyte proliferation in remote, noninfarcted myocardium in swine. In contrast, regional intracoronary cell infusion did not significantly affect remote zone myocyte remodeling. Global cell administration targeting viable myocardium remote from the infarct may be an effective approach to prevent adverse ventricular remodeling after myocardial infarction.

Cardiosphere-Derived Cells and Ischemic Heart Failure.

After a myocardial infarction, heart tissue becomes irreversibly damaged, leading to scar formation and inevitably ischemic heart failure. Of the many available interventions after a myocardial infarction, such as percutaneous intervention or pharmacological optimization, none can reverse the ischemic insult on the heart and restore cardiac function. Thus, the only available cure for patients with scarred myocardium is allogeneic heart transplantation, which comes with extensive costs, risks, and complications. However, multiple studies have shown that the heart is, in fact, not an end-stage organ and that there are endogenous mechanisms in place that have the potential to spark regeneration. Stem cell therapy has emerged as a potential tool to tap into and activate this endogenous framework. Particularly promising are stem cells derived from cardiac tissue itself, referred to as cardiosphere-derived cells (CDCs). CDCs can be extracted and isolated from the patient's myocardium and then administered by intramyocardial injection or intracoronary infusion. After early success in the animal model, multiple clinical trials have demonstrated the safety and efficacy of autologous CDC therapy in humans. Clinical trials with allogeneic CDCs showed early promising results and pose a potential "off-the-shelf" therapy for patients in the acute setting after a myocardial infarction. The mechanism responsible for CDC-induced cardiac regeneration seems to be a combination of triggering native cardiomyocyte proliferation and recruitment of endogenous progenitor cells, which most prominently occurs via paracrine effects. A further understanding of the mediators involved in paracrine signaling can help with the development of a stem cell-free therapy, with all the benefits and none of the associated complications.

Effect and mechanism of cardiosphere-derived cells in the treatment of heart failure with preserved ejection fraction in rats

Objective To test whether cardiosphere-derived cells (CDCs) were sufficient to decrease manifestations of heart failure with preserved ejection fraction (HFpEF) in hypertensive rats. Methods DS rats (Charles River, Wilmington, Massachusetts) were fed 0.3% NaCl (low-salt) diet until 7 weeks of age.At that time, the diet was switched to an 8% NaCl (high-salt) diet in rats by random assignment.DS rats fed the low-salt diet constituted the control group (n=20). At 13 to 14 weeks of age, rats with the high-salt diet were randomized to receive allogeneic rat CDCs or PBS.Echocardiography long-axis images of the left ventricular systolic and diastolic dimensions.Sirius red was used to assess fibrosis and proliferation. Results E/A ratio increased in the PBS-treated group compared with the control group and the CDCs-treated group [(1.20±0.30) vs.(1.70±0.20) or (1.80±0.16), t=0.782, 0.844, all P<0.001]. LAA kept increasing in the PBS-treated group[(27.20±1.10) mm2 vs.(19.80±0.76) mm2 or (17.80±0.82) mm2, t=0.892, 0.774, all P<0.001]. The time constant of isovolumic LV pressure fall was prolonged in placebo-treated animals compared with CDCs-treated animals and control rats[(6.2±0.3)×103 mmHg/s vs.(9.4±0.4)×103 mmHg/s, t=0.382, P=0.024; (6.2±0.3)×103 mmHg/s vs.(9.1±0.5)×103 mmHg/s, t=0.883, P=0.022]. LVEDP was 2-fold higher in placebo-treated group than in CDC-treated and control animals[(17±10) mmHg vs.(8±3) mmHg, t=0.922, P=0.003; (17±10) mmHg vs.(9±4) mmHg, t=0.922, P=0.004]. A dramatic improvement of survival was observed in CDC-treated rats (Kaplan-Meier survival curves) (P=0.027). Cardiac myofibroblasts increased dramatically in PBS-treated(110/field vs.46/field, P<0.001). Inflammatory cytokines expression siginficantly increased in PBS-treated group. Conclusion CDCs improves survival in a rat model of HFpEF through reducing inflammation and fibrosis. Key words: Stem cells; Heart failure; Fibrosis; Rats

Intracoronary allogeneic cardiosphere-derived stem cells are safe for use in dogs with dilated cardiomyopathy.

Cardiosphere‐derived cells (CDCs) have been shown to reduce scar size and increase viable myocardium in human patients with mild/moderate myocardial infarction. Studies in rodent models suggest that CDC therapy may confer therapeutic benefits in patients with non‐ischaemic dilated cardiomyopathy (DCM). We sought to determine the safety and efficacy of allogeneic CDC in a large animal (canine) model of spontaneous DCM. Canine CDCs (cCDCs) were grown from a donor dog heart. Similar to human CDCs, cCDCs express CD105 and are slightly positive for c‐kit and CD90. Thirty million of allogeneic cCDCs was infused into the coronary vessels of Doberman pinscher dogs with spontaneous DCM. Adverse events were closely monitored, and cardiac functions were measured by echocardiography. No adverse events occurred during and after cell infusion. Histology on dog hearts (after natural death) revealed no sign of immune rejection from the transplanted cells.

ALLogeneic Heart STem Cells to Achieve Myocardial Regeneration (ALLSTAR) Trial: Rationale and Design

Autologous cardiosphere-derived cells (CDCs) were the first therapeutic modality to demonstrate myocardial regeneration with a decrease in scar size and an increase in viable, functional tissue. Widespread applicability of autologous CDC therapy is limited by the need for patient-specific myocardial biopsy, cell processing, and quality control, resulting in delays to therapy and inherent logistical and economic constraints. Preclinical data had demonstrated equivalent efficiency of allogeneic to autologous CDCs. The ALLogeneic Heart STem Cells to Achieve Myocardial Regeneration (ALLSTAR) trial is a multicenter randomized, double-blind, placebo-controlled phase 1/2 safety and efficacy trial of intracoronary delivery of allogeneic CDCs (CAP-1002) in patients with myocardial infarction (MI) and ischemic left ventricular dysfunction. The phase 1 safety cohort enrolled 14 patients in an open-label, nonrandomized, dose-escalation safety trial. The phase 2 trial is a doubleblind, randomized, placebo-controlled trial that will compare intracoronary CDCs to placebo in a 2:1 allocation and will enroll up to 120 patients. The primary endpoint for both phases is safety at 1 month. For phase 2, the primary efficacy endpoint is relative change from baseline in infarct size at 12 months, as assessed by magnetic resonance imaging. The ALLSTAR trial employs a “seamless” WOVE 1 design that enables continuous enrollment from phase 1 to phase 2 and will evaluate the safety of intracoronary administration of allogeneic CDCs and its efficacy in decreasing infarct size in post-MI patients.

Repeated transplantation of allogeneic cardiosphere-derived cells boosts therapeutic benefits without immune sensitization in a rat model of myocardial infarction

A single dose of allogeneic cardiosphere-derived cells (CDCs) improves cardiac function and reduces scarring, and increases viable myocardium in the infarcted rat and pig heart without eliciting a detrimental immune response. Clinical trials using single doses of allogeneic human CDCs are underway. It is unknown whether repeat dosing confers additional benefit or if it elicits an immune response. Wistar-Kyoto rats underwent coronary artery ligation and intramyocardial injection of CDCs, with a second thoracotomy and repeat CDC injection 3 weeks later. Treatment permutations included 2 doses of allogeneic Brown-Norway CDCs (n = 24), syngeneic Wistar-Kyoto CDCs (n = 24), xenogeneic human CDCs (n = 24) or saline (n = 8). Cardiac function was assessed by transthoracic echocardiography, infarct size and inflammatory infiltration by histology, and cellular and humoral immune responses by lymphocyte proliferation and alloantibody assays. Repeat dosing of allogeneic and syngeneic CDCs improved ejection fraction by 5.2% (95% CI 2.1 to 8.3) and 6.8% (95% CI 3.8 to 9.8) after the first dose, and by 3.4% (95% CI 0.1% to 6.8%) and 6.4% (95% CI 4.2% to 8.6%) after the second dose. Infarct size was equally reduced with repeat dosing of syngeneic and allogeneic CDCs relative to xenogeneic and control treatments (p < 0.0001). Significant rejection-like infiltrates were present only in the xenogeneic group; likewise, lymphocyte proliferation and antibody assays were positive in the xenogeneic and negative in syngeneic and allogeneic groups. Repeat dosing of allogeneic CDCs in immunocompetent rats is safe and effective, consistent with the known immunomodulatory and anti-inflammatory properties of CDCs. These findings motivate clinical testing of repeatedly dosed CDCs for chronic heart disease.

Durable Benefits of Cellular Postconditioning: Long-Term Effects of Allogeneic Cardiosphere-Derived Cells Infused After Reperfusion in Pigs with Acute Myocardial Infarction.

BackgroundInfusion of allogeneic cardiosphere‐derived cells (allo‐CDCs) postreperfusion elicits cardioprotective cellular postconditioning in pigs with acute myocardial infarction. However, the long‐term effects of allo‐CDCs have not been assessed. We performed a placebo‐controlled pivotal study for long‐term evaluation, as well as shorter‐term mechanistic studies.Methods and ResultsMinipigs underwent 1.5‐hour mid‐left anterior descending balloon occlusion followed by reperfusion and were randomized to receive intracoronary allo‐CDCs or vehicle 30 minutes postreperfusion. Left ventriculography (LVG) demonstrated preserved ejection fraction (EF) and attenuation of LV remodeling in CDC‐treated pigs. Pigs underwent cardiac magnetic resonance imaging (MRI) and LVG 1 hour and 8 weeks after therapy to evaluate efficacy. MRI showed improvement of EF and attenuation of LV remodeling immediately after allo‐CDC infusion. In addition, allo‐CDCs improved regional function and decreased hypertrophy 2 months post‐treatment. Histological analysis revealed increased myocardial salvage index, enhanced vascularity, sustained reductions in infarct size/area at risk and scar transmurality, and attenuation of collagen deposition in the infarct zone of allo‐CDC‐treated pigs at 2 months. Allo‐CDCs did not evoke lymphohistiocytic infiltration or systemic humoral memory response. Short‐term experiments designed to probe mechanism revealed antiapoptotic effects of allo‐CDCs on cardiomyocytes and increases in cytoprotective macrophages, but no increase in overall inflammatory cell infiltration 2 hours after cell therapy.ConclusionsAllo‐CDC infusion postreperfusion is safe, improves cardiac function, and attenuates scar size and remodeling. The favorable effects persist for at least 2 months after therapy. Thus, cellular postconditioning confers not only acute cardioprotection, but also lasting structural and functional benefits.

Widespread Myocardial Delivery of Heart-Derived Stem Cells by Nonocclusive Triple-Vessel Intracoronary Infusion in Porcine Ischemic Cardiomyopathy: Superior Attenuation of Adverse Remodeling Documented by Magnetic Resonance Imaging and Histology.

Single-vessel, intracoronary infusion of stem cells under stop-flow conditions has proven safe but achieves only limited myocardial coverage. Continuous flow intracoronary delivery to one or more coronary vessels may achieve broader coverage for treating cardiomyopathy, but has not been investigated. Using nonocclusive coronary guiding catheters, we infused allogeneic cardiosphere-derived cells (CDCs) either in a single vessel or sequentially in all three coronary arteries in porcine ischemic cardiomyopathy and used magnetic resonance imaging (MRI) to assess structural and physiological outcomes. Vehicle-infused animals served as controls. Single-vessel stop-flow and continuous-flow intracoronary infusion revealed equivalent effects on scar size and function. Sequential infusion into each of the three major coronary vessels under stop-flow or continuous-flow conditions revealed equal efficacy, but less elevation of necrotic biomarkers with continuous-flow delivery. In addition, multi-vessel delivery resulted in enhanced global and regional tissue function compared to a triple-vessel placebo-treated group. The functional benefits after global cell infusion were accompanied histologically by minimal inflammatory cellular infiltration, attenuated regional fibrosis and enhanced vessel density in the heart. Sequential multi-vessel non-occlusive delivery of CDCs is safe and provides enhanced preservation of left ventricular function and structure. The current findings provide preclinical validation of the delivery method currently undergoing clinical testing in the Dilated cardiomYopathy iNtervention With Allogeneic MyocardIally-regenerative Cells (DYNAMIC) trial of CDCs in heart failure patients.

Heart-Derived Stem Cells in Miniature Swine with Coronary Microembolization: Novel Ischemic Cardiomyopathy Model to Assess the Efficacy of Cell-Based Therapy

A major problem in translating stem cell therapeutics is the difficulty of producing stable, long-term severe left ventricular (LV) dysfunction in a large animal model. For that purpose, extensive infarction was created in sinclair miniswine by injecting microspheres (1.5 × 106 microspheres, 45 μm diameter) in LAD. At 2 months after embolization, animals (n = 11) were randomized to receive allogeneic cardiosphere-derived cells derived from atrium (CDCs: 20 × 106, n = 5) or saline (untreated, n = 6). Four weeks after therapy myocardial function, myocyte proliferation (Ki67), mitosis (phosphor-Histone H3; pHH3), apoptosis, infarct size (TTC), myocyte nuclear density, and cell size were evaluated. CDCs injected into infarcted and remodeled remote myocardium (global infusion) increased regional function and global function contrasting no change in untreated animals. CDCs reduced infarct volume and stimulated Ki67 and pHH3 positive myocytes in infarct and remote regions. As a result, myocyte number (nuclear density) increased and myocyte cell diameter decreased in both infarct and remote regions. Coronary microembolization produces stable long-term ischemic cardiomyopathy. Global infusion of CDCs stimulates myocyte regeneration and improves left ventricular ejection fraction. Thus, global infusion of CDCs could become a new therapy to reverse LV dysfunction in patients with asymptomatic heart failure.

Allogeneic cardiosphere-derived cells for myocardial regeneration: current progress and recent results.

Early-phase clinical testing of autologous cardiosphere-derived cells (CDCs) has yielded intriguing results, consistent with therapeutic myocardial regeneration. However, autologous therapy is associated with significant technical, timing, economic and logistic constraints, prompting researchers to explore the potential of allogeneic CDC therapy. CDCs exhibit a favorable immunologic antigenic profile and are hypoimmunogenic in vitro. Preclinical studies in immunologically mismatched animals demonstrate that allogeneic CDC transplantation without immunosuppression is safe and produces sustained functional and structural benefits through stimulation of endogenous regenerative pathways. Currently, allogeneic human CDCs are being tested clinically in the ALLSTAR and DYNAMIC trials. Potential establishment of clinical safety and efficacy of allogeneic CDCs combined with generation of highly standardized, 'off-the-shelf' allogeneic cellular products would facilitate broad clinical adoption of cell therapy.

Abstract 18236: Dilated cardiomYopathy iNtervention With Allogeneic MyocardIally-regenerative Cells (DYNAMIC): Six Month Safety and Exploratory Efficacy Results

Background: In the CADUCEUS trial, autologous cardiosphere-derived cells (CDCs) decreased infarct size and increased viable tissue in post-MI subjects. In ALLSTAR Phase I, allogeneic CDCs (CAP-1002) were safe and well-tolerated. The DYNAMIC trial is an open-label dose escalating safety trial of multi-vessel intra-coronary CAP 1002 in subjects with dilated cardiomyopathy. Methods &amp; Results: Subjects were matched with CAP-1002 cell lines to which they had no donor specific antibodies by single antigen bead testing. Fourteen subjects (mean age 60.6 yr; range 32-76 years) with NHYA Class III symptoms and echo EF ≤35% (Screening Cardiac CT: mean 26.9%; range 16-34%) due to ischemic (n=7) or non-ischemic cause (n=7) were prospectively enrolled. Four escalating total CAP-1002 doses from 37.5M to 75M were infused via a sequential non-occlusive intracoronary catheter technique, divided among the 3 major coronary arteries (LAD, RCA and circumflex). Post-procedural cardiac enzymes (troponin and CKMB) were measured, with no clinically-significant increases observed in the 24 hr post-infusion. No pre-specified primary safety endpoints occurred; (post infusion reduction of TIMI flow for &gt; 3 minutes, VT/VF, sudden death, major adverse cardiac (MACE) events within 72 hours of infusion, or acute myocarditis within 1 month). Further safety data and exploratory efficacy endpoints include BNP, 6 minute walk and VO2max as well as EF and volumes measured by both echo and cardiac CT at 6 and 12 months. Conclusion: Multi-vessel non-occlusive intracoronary infusion of CAP 1002 in subjects with dilated cardiomyopathy appears to be safe. Six month safety endpoint and adverse event data, as well as exploratory efficacy measures, will be available for presentation November 2015.

Abstract 11714: Allogeneic Cardiosphere-Derived Cells Administered at the Time of Reperfusion Only Improve Ejection Fraction When Infused to Ischemic as well as Remote Myocardial Regions in Swine With Acute Myocardial Infarction

Introduction: While intracoronary infusion of cardiosphere-derived cells (CDCs) to myocardial infarcts using the stop-flow technique reduces scar volume, ejection fraction (EF) remains unchanged. Hypothesis: We hypothesized that this may relate to ineffective treatment of myocyte loss in normally-perfused remote regions which could negatively impact EF. We therefore compared CDC infusion to the entire heart with conventional regional infusion to the infarct-related artery. Methods: Swine (n=24) chronically treated with cyclosporine (100 mg/day) underwent a 1-hour LAD occlusion and EF decreased from 60 ± 2% at baseline to 46 ± 2% after reperfusion (p&lt;0.05 vs. baseline). We infused either 10x10^6 intracoronary allogeneic CDCs via stop-flow infusion (regional LAD infusion), 20x10^6 intracoronary allogeneic CDCs to the entire heart under flow (global infusion) or vehicle 30 minutes after reperfusion. Four weeks later we assessed left ventricular function (echo), myocyte proliferation (Ki67), infarct size (TTC), myocyte nuclear density and cell size. Data were compared to vehicle. Results: Regional LAD infusion increased wall thickening and reduced scar volume but did not affect EF (Table). In contrast, global infusion increased EF despite an insignificant reduction in infarct volume. This was accompanied by 2-fold increases in myocyte proliferation (Ki67) in border and remote regions which did not change with regional LAD infusion. Global infusion increased myocyte nuclear density by 12% and decreased cell size by 9% while there were no significant changes after regional LAD infusion. Conclusion: Although regional LAD infusion reduces scar size and improves regional function, only global infusion improves EF since it effectively stimulates endogenous myocyte regeneration throughout the entire left ventricle. Thus, global infusion may more effectively prevent deleterious post-infarction remodeling than regional administration alone.