Farrell O. Mendelsohn

Regional Angiogenesis With Vascular Endothelial Growth Factor in Peripheral Arterial Disease A Phase II Randomized, Double-Blind, Controlled Study of Adenoviral Delivery of Vascular Endothelial Growth Factor 121 in Patients With Disabling Intermittent Claudication

Background—“Therapeutic angiogenesis” seeks to improve perfusion by the growth of new blood vessels. The Regional Angiogenesis with Vascular Endothelial growth factor (RAVE) trial is the first major randomized study of adenoviral vascular endothelial growth factor (VEGF) gene transfer for the treatment of peripheral artery disease (PAD). Methods and Results—This phase 2, double-blind, placebo-controlled study was designed to test the efficacy and safety of intramuscular delivery of AdVEGF121, a replication-deficient adenovirus encoding the 121-amino-acid isoform of vascular endothelial growth factor, to the lower extremities of subjects with unilateral PAD. In all, 105 subjects with unilateral exercise-limiting intermittent claudication during 2 qualifying treadmill tests, with peak walking time (PWT) between 1 to 10 minutes, were stratified on the basis of diabetic status and randomized to low-dose (4×109 PU) AdVEGF121, high-dose (4×1010 PU) AdVEGF121, or placebo, administered as 20 intramuscular injections to the index leg in a single session. The primary efficacy end point, change in PWT (&Dgr;PWT) at 12 weeks, did not differ between the placebo (1.8±3.2 minutes), low-dose (1.6±1.9 minutes), and high-dose (1.5±3.1 minutes) groups. Secondary measures, including &Dgr;PWT, ankle-brachial index, claudication onset time, and quality-of-life measures (SF-36 and Walking Impairment Questionnaire), were also similar among groups at 12 and 26 weeks. AdVEGF121 administration was associated with increased peripheral edema. Conclusions—A single unilateral intramuscular administration of AdVEGF121 was not associated with improved exercise performance or quality of life in this study. This study does not support local delivery of single-dose VEGF121 as a treatment strategy in patients with unilateral PAD.

Therapeutic angiogenesis with recombinant fibroblast growth factor-2 for intermittent claudication (the TRAFFIC study): a randomised trial

BACKGROUND Recombinant fibroblast growth factor-2 (rFGF-2) improves perfusion in models of myocardial and hindlimb ischaemia. We investigated whether one or two doses of intra-arterial rFGF-2 improves exercise capacity in patients with moderate-to-severe intermittent claudication. METHODS 190 patients with intermittent claudication caused by infra-inguinal atherosclerosis were randomly assigned (1:1:1) bilateral intra-arterial infusions of placebo on days 1 and 30 (n=63); rFGF-2 (30 microg/kg) on day 1 and placebo on day 30 (single-dose, n=66); or rFGF-2 (30 microg/kg) on days 1 and 30 (double-dose, n=61). Primary outcome was 90-day change in peak walking time. Secondary outcomes included ankle-brachial pressure index and safety. The main analysis was per protocol. FINDINGS Before 90 days, six patients had undergone peripheral revascularisation and were excluded, and ten withdrew or had missing data. 174 were therefore assessed for primary outcome. Peak walking time at 90 days was increased by 0.60 min with placebo, by 1.77 min with single-dose, and by 1.54 min with double-dose. By ANOVA, the difference between groups was p=0.075. In a secondary intention-to-treat analysis, in which all 190 patients were included, the difference was p=0.034. Pairwise comparison showed a significant difference between placebo and single-dose (p=0.026) but placebo and double-dose did not differ by much (p=0.45). Serious adverse events were similar in all groups. INTERPRETATION Intra-arterial rFGF-2 resulted in a significant increase in peak walking time at 90 days; repeat infusion at 30 days was no better than one infusion. The findings of TRAFFIC provide evidence of clinical therapeutic angiogenesis by intra-arterial infusion of an angiogenic protein.

Intramyocardial, Autologous CD34+ Cell Therapy for Refractory Angina

Rationale: A growing number of patients with coronary disease have refractory angina. Preclinical and early-phase clinical data suggest that intramyocardial injection of autologous CD34+ cells can improve myocardial perfusion and function. Objective: Evaluate the safety and bioactivity of intramyocardial injections of autologous CD34+ cells in patients with refractory angina who have exhausted all other treatment options. Methods and Results: In this prospective, double-blind, randomized, phase II study (ClinicalTrials.gov identifier: NCT00300053), 167 patients with refractory angina received 1 of 2 doses (1×105 or 5×105 cells/kg) of mobilized autologous CD34+ cells or an equal volume of diluent (placebo). Treatment was distributed into 10 sites of ischemic, viable myocardium with a NOGA mapping injection catheter. The primary outcome measure was weekly angina frequency 6 months after treatment. Weekly angina frequency was significantly lower in the low-dose group than in placebo-treated patients at both 6 months (6.8±1.1 versus 10.9±1.2, P=0.020) and 12 months (6.3±1.2 versus 11.0±1.2, P=0.035); measurements in the high-dose group were also lower, but not significantly. Similarly, improvement in exercise tolerance was significantly greater in low-dose patients than in placebo-treated patients (6 months: 139±151 versus 69±122 seconds, P=0.014; 12 months: 140±171 versus 58±146 seconds, P=0.017) and greater, but not significantly, in the high-dose group. During cell mobilization and collection, 4.6% of patients had cardiac enzyme elevations consistent with non-ST segment elevation myocardial infarction. Mortality at 12 months was 5.4% in the placebo-treatment group with no deaths among cell-treated patients. Conclusions: Patients with refractory angina who received intramyocardial injections of autologous CD34+ cells (105 cells/kg) experienced significant improvements in angina frequency and exercise tolerance. The cell-mobilization and -collection procedures were associated with cardiac enzyme elevations, which will be addressed in future studies.

Sex differences in coronary artery size assessed by intravascular ultrasound

BACKGROUND Women have worse outcomes after myocardial infarction and coronary revascularization. The explanations are likely multifactorial but may include smaller coronary artery size. Smaller luminal diameter has been confirmed angiographically; however, because of possible confounding effects of coronary remodeling, angiographically silent atherosclerosis, and body size, it is unclear if there is a true sex influence on arterial size. METHODS We performed intravascular ultrasound on left main (LM) and proximal left anterior descending (LAD) coronary artery segments that were free of significant atherosclerosis in 50 men and 25 women. Arterial and luminal areas were measured by planimetry and corrected for body surface area. We evaluated associations between sex and coronary dimensions with univariate and then multiple linear regression analyses. RESULTS Mean uncorrected LM and LAD arterial areas were smaller in women than in men (21.53 vs 26.95 mm(2), P <.001, and 14. 68 vs 19.94 mm(2), P =.002, respectively), as were mean LM and LAD luminal areas (15.94 vs 18.79 mm(2), P =.020, and 10.13 vs 12.71 mm(2), P =.036, respectively). In multivariate models accounting for body surface area and controlling for other factors, sex independently predicted corrected LM and LAD arterial area. In analyses that additionally controlled for plaque area, sex independently predicted corrected LAD luminal area. CONCLUSIONS LM and LAD arteries are smaller in women, independent of body size. This suggests an intrinsic sex effect on coronary dimensions. Future studies should investigate underlying mechanisms because they may lead to novel therapeutic strategies and improved outcomes for women with coronary artery disease.

Acute hemodynamic changes during carotid artery stenting

To determine the clinical significance of acute hemodynamic disturbances during stenting in the carotid sinus region, we assessed the relation between intraprocedural changes in heart rate (HR) and blood pressure (BP) and adverse neurologic and cardiac outcomes. Eighteen patients underwent carotid stenting with the Wallstent (Schneider Inc). Suitable candidates had at least 60% diameter stenosis of the carotid artery by angiography. Initial and nadir HR and BP were recorded during the predilatation, stent delivery, and postdilatation periods. Bradycardia was defined as HR < or =60 beats/min and hypotension as systolic BP < or =100 mm Hg. Nineteen Wallstents were successfully deployed in all 19 carotid arteries. Some degree of bradycardia or hypotension occurred in 68% of carotid stent procedures, but administration of vasoactive medications was necessary in only 7 patients (37%) with more persistent hemodynamic disturbances. Hypotension or the need for continuous vasopressor therapy was significantly more common during postdilatation (32%) than in the predilatation period (5%) (p = 0.02). Bradycardia was not reduced by prophylactic atropine. In 1 patient the hemodynamic response to stenting may have contributed to an adverse neurologic and cardiac outcome. Thus, despite frequent fluctuations in HR and BP, most carotid stenting procedures were performed with excellent overall results, even in patients at high risk.

An Open-Label Dose Escalation Study to Evaluate the Safety of Administration of Nonviral Stromal Cell-Derived Factor-1 Plasmid to Treat Symptomatic Ischemic Heart Failure

Rationale: Preclinical studies indicate that adult stem cells induce tissue repair by activating endogenous stem cells through the stromal cell-derived factor-1:chemokine receptor type 4 axis. JVS-100 is a DNA plasmid encoding human stromal cell-derived factor-1. Objective: We tested in a phase 1, open-label, dose-escalation study with 12 months of follow-up in subjects with ischemic cardiomyopathy to see if JVS-100 improves clinical parameters. Methods and Results: Seventeen subjects with ischemic cardiomyopathy, New York Heart Association class III heart failure, with an ejection fraction ⩽40% on stable medical therapy, were enrolled to receive 5, 15, or 30 mg of JVS-100 via endomyocardial injection. The primary end points for safety and efficacy were at 1 and 4 months, respectively. The primary safety end point was a major adverse cardiac event. Efficacy end points were change in quality of life, New York Heart Association class, 6-minute walk distance, single photon emission computed tomography, N-terminal pro-brain natruretic peptide, and echocardiography at 4 and 12 months. The primary safety end point was met. At 4 months, all of the cohorts demonstrated improvements in 6-minute walk distance, quality of life, and New York Heart Association class. Subjects in the 15- and 30-mg dose groups exhibited improvements in 6-minute walk distance (15 mg: median [range]: 41 minutes [3–61 minutes]; 30 mg: 31 minutes [22–74 minutes]) and quality of life (15 mg: –16 points [+1 to –32 points]; 30 mg: –24 points [+17 to –38 points]) over baseline. At 12 months, improvements in symptoms were maintained. Conclusions: These data highlight the importance of defining the molecular mechanisms of stem cell-based tissue repair and suggest that overexpression of stromal cell-derived factor-1 via gene therapy is a strategy for improving heart failure symptoms in patients with ischemic cardiomyopathy.

Safety and efficacy of patient specific intramuscular injection of HGF plasmid gene therapy on limb perfusion and wound healing in patients with ischemic lower extremity ulceration: Results of the HGF-0205 trial

OBJECTIVES We have previously reported the results of a dose-finding phase II trial showing that HGF angiogenic gene therapy can increase TcPO2 compared with placebo in patients with critical limb ischemia (CLI). The purpose of this randomized placebo controlled multi-center trial was to further assess the safety and clinical efficacy of a modified HGF gene delivery technique in patients with CLI and no revascularization options. METHODS Patients with lower extremity ischemic tissue loss (Rutherford 5 and 6) received three sets of eight intramuscular injections every 2 weeks of HGF plasmid under duplex ultrasound guidance. Injection locations were individualized for each patient based on arteriographically defined vascular anatomy. Primary safety end point was incidence of adverse events (AE) or serious adverse events (SAE). Clinical end points included change from baseline in toe brachial index (TBI), rest pain assessment by a 10 cm visual analogue scale (VAS) as well as wound healing, amputation, and survival at 3 and 6 months. RESULTS Randomization ratio was 3:1 HGF (n = 21) vs placebo (n = 6). Mean age was 76 ± 2 years, with 56% male and 59% diabetic. There was no difference in demographics between groups. There was no difference in AEs or SAEs, which consisted mostly of transient injection site discomfort, worsening of CLI, and intercurrent illnesses. Change in TBI significantly improved from baseline at 6 months in the HGF-treated group compared with placebo (0.05 ± 0.05 vs -0.17 ± 0.04; P = .047). Change in VAS from baseline at 6 months was also significantly improved in the HGF-treated group compared with placebo (-1.9 ± 1.3 vs +0.06 ± 0.2; P = .04). Complete ulcer healing at 12 months occurred in 31% of the HGF group and 0% of the placebo (P = .28) There was no difference in major amputation of the treated limb (HGF 29% vs placebo 33%) or mortality at 12 months (HGF 19% vs placebo 17%) between groups. CONCLUSION HGF gene therapy using a patient vascular anatomy specific delivery technique appears safe, maintained limb perfusion, and decreased rest pain in patients with CLI compared with placebo. A larger study to assess the efficacy of this therapy on more clinically relevant end points is warranted.

A Randomized, Controlled Pilot Study of Autologous CD34+ Cell Therapy for Critical Limb Ischemia

Background—Critical limb ischemia portends a risk of major amputation of 25% to 35% within 1 year of diagnosis. Preclinical studies provide evidence that intramuscular injection of autologous CD34+ cells improves limb perfusion and reduces amputation risk. In this randomized, double-blind, placebo-controlled pilot study, we evaluated the safety and efficacy of intramuscular injections of autologous CD34+ cells in subjects with moderate or high-risk critical limb ischemia, who were poor or noncandidates for surgical or percutaneous revascularization (ACT34-CLI). Methods and Results—Twenty-eight critical limb ischemia subjects were randomized and treated: 7 to 1×105 (low-dose) and 9 to 1×106 (high-dose) autologous CD34+ cells/kg; and 12 to placebo (control). Intramuscular injections were distributed into 8 sites within the ischemic lower extremity. At 6 months postinjection, 67% of control subjects experienced a major or minor amputation versus 43% of low-dose and 22% of high-dose cell-treated subjects (P=0.137). This trend continued at 12 months, with 75% of control subjects experiencing any amputation versus 43% of low-dose and 22% of high-dose cell-treated subjects (P=0.058). Amputation incidence was lower in the combined cell-treated groups compared with control group (6 months: P=0.125; 12 months: P=0.054), with the low-dose and high-dose groups individually showing trends toward improved amputation-free survival at 6 months and 12 months. No adverse safety signal was associated with cell administration. Conclusions—This study provides evidence that intramuscular administration of autologous CD34+ cells was safe in this patient population. Favorable trends toward reduced amputation rates in cell-treated versus control subjects were observed. These findings warrant further exploration in later-phase clinical trials. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00616980

An Open Label Dose Escalation Study to Evaluate the Safety of Administration of Non-Viral SDF-1 Plasmid to Treat Symptomatic Ischemic Heart Failure

Rationale: Preclinical studies indicate that adult stem cells induce tissue repair by activating endogenous stem cells through the stromal cell-derived factor-1:chemokine receptor type 4 axis. JVS-100 is a DNA plasmid encoding human stromal cell-derived factor-1. Objective: We tested in a phase 1, open-label, dose-escalation study with 12 months of follow-up in subjects with ischemic cardiomyopathy to see if JVS-100 improves clinical parameters. Methods and Results: Seventeen subjects with ischemic cardiomyopathy, New York Heart Association class III heart failure, with an ejection fraction ⩽40% on stable medical therapy, were enrolled to receive 5, 15, or 30 mg of JVS-100 via endomyocardial injection. The primary end points for safety and efficacy were at 1 and 4 months, respectively. The primary safety end point was a major adverse cardiac event. Efficacy end points were change in quality of life, New York Heart Association class, 6-minute walk distance, single photon emission computed tomography, N-terminal pro-brain natruretic peptide, and echocardiography at 4 and 12 months. The primary safety end point was met. At 4 months, all of the cohorts demonstrated improvements in 6-minute walk distance, quality of life, and New York Heart Association class. Subjects in the 15- and 30-mg dose groups exhibited improvements in 6-minute walk distance (15 mg: median [range]: 41 minutes [3–61 minutes]; 30 mg: 31 minutes [22–74 minutes]) and quality of life (15 mg: –16 points [+1 to –32 points]; 30 mg: –24 points [+17 to –38 points]) over baseline. At 12 months, improvements in symptoms were maintained. Conclusions: These data highlight the importance of defining the molecular mechanisms of stem cell-based tissue repair and suggest that overexpression of stromal cell-derived factor-1 via gene therapy is a strategy for improving heart failure symptoms in patients with ischemic cardiomyopathy.

Adventitial Delivery of an Allogeneic Bone Marrow–Derived Adherent Stem Cell in Acute Myocardial Infarction Phase I Clinical Study

Rationale: MultiStem is an allogeneic bone marrow–derived adherent adult stem cell product that has shown efficacy in preclinical models of acute myocardial infarction (AMI). In this phase I clinical trial in patients with first ST-elevation–myocardial infarction (STEMI), we combine first-in-man delivery of MultiStem with a first-in-coronary adventitial delivery system to determine the effects of this system on left ventricular function at 4 months after AMI. Objective: Test the effects of adventitial delivery of Multistem in the peri-infarct period in patients with first STEMI. Methods and Results: This study was a phase I, open-label, dose-escalating registry control group study. Nineteen patients received MultiStem (20 million, n=6; 50 million, n=7; or 100 million, n=6) and 6 subjects were assigned to the registry control group. Two to 5 days after AMI, we delivered MultiStem to the adventitia of the infarct-related vessel in patients with first-time STEMI. All patients underwent primary percutaneous coronary intervention with resulting Thrombolysis In Myocardial Infarction grade 3 flow and with ejection fraction (EF) ⩽45% as determined by echocardiogram or left ventriculogram within 12 hours of primary percutaneous coronary intervention. The cell product (20 million, 50 million, or 100 million) was well tolerated, and no serious adverse events were deemed related to MultiStem. There was no increase in creatine kinase-MB or troponin associated with the adventitial delivery of MultiStem. In patients with EF determined to be ⩽45% by a core laboratory within 24 hours before the MultiStem injection, we observed a 0.9 (n=4), 3.9 (n=4), 13.5 (n=5), and 10.9 (n=2) percent absolute increases in EF in the registry, 20 million, 50 million, and 100 million dose groups, respectively. The increases in EF in the 50 million and 100 million groups were accompanied by 25.4 and 8.4 mL increases in left ventricular stroke volume. Conclusions: In this study, the delivery of MultiStem to the myocardium in patients with recent STEMI was well tolerated and safe. In patients who exhibited significant myocardial damage, the delivery of ≥50 million MultiStem resulted in improved EF and stroke volume 4 months later. These findings support further development of MultiStem in patients with AMI and they validate the potential of a system for delivery of adult stem cells at any time after primary percutaneous coronary intervention.