First‐in‐Man Study of the Low‐Dose Paclitaxel Using the COBRA‐P Drug‐Eluting Coronary Stent System With a Novel Biodegradable Coating in De Novo Coronary Lesions

Objective The aim of this first‐in‐man trial was to evaluate vessel response of two doses of the balloon expandable Cobra‐P drug‐eluting coronary stent (DES). Background The Cobra‐P DES system consists of a cobalt chromium alloy with bioabsorbable siloxane sol–gel matrix coating that elutes low dose paclitaxel. Methods A total of 60 lesions (54 patients) were sequentially assigned to extremely low‐dose (group A: 3.7 µg/18 mm; n = 30, 1/33 dose of the TAXUS Liberte) or low‐dose (group B: 8 µg/18 mm; n = 30) arm. Intravascular ultrasound images were obtained at post‐procedure and at 4 months. Results Patient and lesion characteristics were matched between the two groups except for the higher prevalence of men in group B. At 4 months, there were no significant differences in neointimal obstruction (13.5 ± 9.5% vs. 10.9 ± 7.8%, P = 0.276), and maximum cross‐sectional narrowing (31.2 ± 14.3% vs. 28.6 ± 16.1%, P = 0.523) between the two groups. Late‐acquired incomplete stent apposition occurred in four cases in each arm ( P = 1.000). Although the volume of late‐acquired incomplete stent apposition did not differ between the two groups (1.0 ± 0.6 mm 3 vs. 8.6 ± 10.9 mm 3 , P = 0.200), maximum late‐acquired incomplete stent apposition area was significantly smaller in group A than in group B (1.1 ± 0.3 mm 2 vs. 2.5 ± 1.4 mm 2 , P = 0.029). Conclusions In the first‐in‐man study of the Cobra‐P DES, neointimal hyperplasia at 4 months appears to be similar between extremely low‐dose and low‐dose groups. Although the incidence of late‐acquired incomplete stent apposition was similar, the magnitude of the late‐acquired gap between the stent and vessel was greater in the low‐dose group compared with the extremely low‐dose group.