Background: This phase 1/2 study investigated the safety of percutaneous catheter-based gene transfer of naked plasmid DNA encoding for vascular endothelial growth factor 2 (phVEGF2) to left ventricular (LV) myocardium in a prospective, randomized, double-blind, placebo-controlled, dose-escalating study of inoperable patients with class III or IV angina.
Methods and results: A steerable deflectable 8F catheter with a 27-gauge needle at its distal tip was advanced percutaneously to the endocardial surface of the LV in 19 patients (age, 61+/-2 years) with chronic myocardial ischemia who were not candidates for conventional revascularization. Patients were randomized in a double-blind fashion to receive 6 injections (total volume, 6.0 mL) of placebo or phVEGF2 in doses of 200 microg (n=9), 800 microg (n=9), or 2000 microg (n=1) guided by LV electromechanical (NOGA) mapping with a gene-to-placebo ratio of 2:1. A total of 114 LV injections were delivered and caused no hemodynamic alterations, sustained ventricular arrhythmias, ECG evidence of infarction, or ventricular perforation. End-point analysis at 12 weeks disclosed a statistically significant improvement in Canadian Cardiovascular Society (CCS) angina class in phVEGF2-treated versus placebo-treated patients (-1.3 versus -0.1, P=0.04). Remaining efficacy end points--including change in exercise duration (91.8 versus 3.9 seconds), functional improvement by > or =2 CCS classes (9 of 12 versus 1 of 6), and Seattle Angina Questionnaire data--all showed strong trends favoring efficacy of phVEGF2 versus placebo treatment.
Conclusions: This phase 1/2, double-blind, randomized trial provides preliminary data that support safety of phVEGF2 catheter-mediated myocardial gene transfer. The statistically significant reduction in anginal class and strong positive trends for remaining end points suggest that a larger phase 2/3 trial is warranted.