Autologous CD34+ Cell Therapy for Refractory Angina: 2-Year Outcomes From the ACT34-CMI Study

An increasing number of patients have refractory angina despite optimal medical therapy and are without further revascularization options. Preclinical studies indicate that human CD34⁺ stem cells can stimulate new blood vessel formation in ischemic myocardium, improving perfusion and function. In ACT34-CMI (N = 167), patients treated with autologous CD34⁺ stem cells had improvements in angina and exercise time at 6 and 12 months compared to placebo; however, the longer-term effects of this treatment are unknown. ACT34 was a phase II randomized, double-blind, placebo-controlled clinical trial comparing placebo, low dose (1 × 10⁵ CD34/kg body weight), and high dose (5 × 10⁵ CD34/kg) using intramyocardial delivery into the ischemic zone following NOGA^® mapping. To obtain longer-term safety and efficacy in these patients, we compiled data of major adverse cardiac events (MACE; death, myocardial infarction, acute coronary syndrome, or heart failure hospitalization) up to 24 months as well as angina and quality of life assessments in patients who consented for 24-month follow-up. A total of 167 patients with class III-IV refractory angina were randomized and completed the injection procedure. The low-dose-treated patients had a significant reduction in angina frequency (p = 0.02, 0.035) and improvements in exercise tolerance testing (ETT) time (p = 0.014, 0.017) compared to the placebo group at 6 and 12 months. At 24 months, patients treated with both low-and high-dose CD34⁺ cells had significant reduction in angina frequency (p = 0.03). At 24 months, there were a total of seven deaths (12.5%) in the control group versus one (1.8%) in the low-dose and two (3.6%) in the high-dose (p = 0.08) groups. At 2 years, MACE occurred at a rate of 33.9%, 21.8%, and 16.2% in control, low-, and high-dose patients, respectively (p = 0.08). Autologous CD34⁺ cell therapy was associated with persistent improvement in angina at 2 years and a trend for reduction in mortality in no-option patients with refractory angina.

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 × 10(5) (low-dose) and 9 to 1 × 10(6) (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.

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 (1×10(5) or 5×10(5) 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 (10(5) 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.

A randomized, controlled study of autologous therapy with bone marrow-derived aldehyde dehydrogenase bright cells in patients with critical limb ischemia

OBJECTIVES

The safety and efficacy of direct intramuscular injections of aldehyde dehydrogenase bright (ALDH(br)) cells isolated from autologous bone marrow mononuclear cells (ABMMNCs) and ABMMNCs were studied in patients with critical limb ischemia (CLI) who were not eligible for percutaneous or surgical revascularization.

BACKGROUND

Many CLI patients are not candidates for current revascularization procedures, and amputation rates are high in these patients. Cell therapy may be a viable option for CLI patients.

METHODS

Safety was the primary objective and was evaluated by occurrence of adverse events. Efficacy, the secondary objective, was evaluated by assessment of Rutherford category, ankle-brachial index (ABI), transcutaneous partial pressure of oxygen (TcPO(2)), quality of life, and pain.

RESULTS

ALDH(br) cells and ABMMNCs were successfully administered to all patients. No therapy-related serious adverse events occurred. Patients treated with ALDH(br) cells (n = 11) showed significant improvements in Rutherford category from baseline to 12 weeks (mean, 4.09 ± 0.30 to 3.46 ± 1.04; P = 0.05) and in ABI at 6 (mean, 0.22 ± 0.19 to 0.30 ± 0.24; P = 0.02), and 12 weeks (mean, 0.36 ± 0.18; P = 0.03) compared with baseline. Patients in the ABMMNC group (n = 10) showed no significant improvements at 6 or 12 weeks in Rutherford category but did show improvement in ABI from baseline to 12 weeks (0.38 ± 0.06 to 0.52 ± 0.16; P = 0.03). No significant changes from baseline were noted in ischemic ulcer grade or TcPO(2) in either group.

CONCLUSIONS

Administration of autologous ALDH(br) cells appears to be safe and warrants further study in patients with CLI.

Results from a phase II multicenter, double-blind placebo-controlled study of Del-1 (VLTS-589) for intermittent claudication in subjects with peripheral arterial disease

BACKGROUND

This study compared VLTS-589 (plasmid encoding the angiomatrix protein Del-1 in conjunction with poloxamer 188) with poloxamer 188 control, for the treatment of intermittent claudication in patients with moderate to severe peripheral arterial disease.

METHODS

Subjects with bilateral intermittent claudication and peak walking time (PWT) between 1 and 10 minutes on 2 qualifying (reproducible; within 25% of each other) treadmill tests were enrolled. Patients received VLTS-589 or poloxamer 188 control, administered as 21 intramuscular injections to each lower extremity (42 mL in each extremity). In addition to safety and tolerability, efficacy evaluations compared to baseline included the following: change in PWT at 90 days (primary end point), change in claudication onset time, change in ankle brachial index (ABI), and change in quality of life measures.

RESULTS

A total of 105 patients were randomized and treated. During the 30, 90, and 180 days follow-up, mean PWT, claudication onset time, and ABI were significantly increased compared to baseline values in both treatment groups with no significant difference between groups in the primary or secondary end points. In addition, both groups demonstrated significantly improved quality of life at follow-up vs baseline, with no significant differences between groups. Serious adverse events were similar in both groups--none were definitely treatment-related.

CONCLUSION

Intramuscular delivery of both Del-1 expressing plasmid and the control resulted in significant improvement in exercise capacity compared to baseline at 30, 90, and 180 days. There was no difference in outcome measures associated with the Del-1 plasmid.

Strychnine-binding proteins in intestinal cells: novel brucine binding site with binding affinities for alkaloids

The purpose of this work was to define the pharmacology of an intestinal epithelial [3H]strychnine binding site. Strychnine, brucine, verapamil and desmethoxyverapamil bind to small intestinal mucosal homogenates with nanomolar affinity at a site not related to the strychnine receptor, which is in the spinal cord. The antidiarrheal agents, fluperamide and loperamide, and several alkaloids have an order of magnitude lower affinity. Agents that bind to cytochrome P450IID6 also displace [3H]strychnine binding, which implies that the binding site may have some properties similar to the catalytic site of this cytochrome P450 enzyme.

Training for independent living unit: its function in a rehabilitation convalescent setting

This article describes a Geriatric Self-Care Unit in a 92 bed Rehabilitation Convalescent Hospital. Ten beds are set aside for this unit. The overall goal of the Self Care Unit (S.C.U.) is to facilitate the patients' discharge into the community. This pilot project has been in effect for six months with 47 patients having completed the program. Results of the program, its problem areas and progress are outlined.

Acute hemiplegia in children complicating upper respiratory infections. Report of three cases with angiographic findings

Three children presented with acute onset of hemiplegia following an upper respiratory infection. Angiography revealed irregulaities, beading, and slow flow of a peripheral branch of a middle cerebral artery. In addition, one child had narrowing of the cervical segment of the internal carotid artery. An inflammatory arteritis of the cervical internal carotid artery is presumably the site of the formation of cerebral emboli.