RESTORE trials show potential benefit of novel DCB

SAN DIEGO — Two trials have demonstrated the noninferiority of a new drug-coated balloon with a novel excipient when compared with a currently available DCB for in-stent restenosis and a second-generation drug-eluting stent in small-vessel disease.

Both the RESTORE ISR China and RESTORE SVD China trials were conducted to enable approval of the Restore paclitaxel-coated balloon (Cardionovum), which has a shellac-ammonium salt excipient that can avoid drug washing-off during catheter delivery to the target lesion site, in China, said two speakers here at TCT 2018.

RESTORE ISR

In the prospective, multicenter, randomized, head-to-head RESTORE ISR China trial, Yundai Chen, PhD, from the department of cardiology at the Chinese PLA General Hospital in Beijing, and colleagues evaluated angiographic efficacy and clinical safety and effectiveness of the Restore DCB compared with the SeQuent Please paclitaxel-coated balloon (B. Braun Medical) in patients with in-stent restenosis.

Nine-month in-segment late lumen loss — the study’s primary endpoint — was 0.38 mm in patients who received the Restore DCB compared with 0.35 mm in patients who received the SeQuent Please DCB. Noninferiority of the Restore DCB, compared with the SeQuent Please DCB, was achieved (P for noninferiority = .02). Results also demonstrated noninferiority based on lesion-level evaluation and in the as-treated analysis, Chen said during her presentation of the data.

Additionally, the researchers observed no differences in the cumulative frequency of in-segment late loss (P = .63) or in-device late loss (P = .51) between the Restore DCB and SeQuent Please DCB groups.

Angiographic results at 9 months showed no significant differences in in-device or in-segment diameter stenosis rate, in-device or in-segment minimal lumen diameter, and in-device or in-segment late loss, according to Chen.

At 1 year, rates of target lesion failure and its components, including target vessel MI and ischemia-driven target lesion revascularization, were not significantly different between patients who received the Restore DCB compared with the SeQuent Please DCB, and no cardiac deaths occurred in either study group. However, there was more target vessel revascularization in the Restore DCB group compared with the SeQuent Please group (23.2% vs. 12.6%; P = .03).

The study, which included 240 patients with stable angina or stabilized ACS, was not without limitations, Chen said. Its sample size, for instance, may mean the study is underpowered to detect differences in clinical endpoints. There was also no distinction between specific DES types, recording of imaging results, such as IVUS and OCT, was not mandatory, and high-risk patients were excluded from the study.

Overall, though, the data paint a cautiously optimistic picture of the Restore DCB, according to Chen.

“The study provided evidence for the efficacy and safety of the Restore DCB angioplasty in coronary in-stent restenosis,” she said. “Longer-term follow-up and larger-scale studies with primary clinical endpoints are needed to evaluate the clinical outcomes with the new Restore DCB in the treatment of DES-in-stent restenosis.”

RESTORE SVD

In the prospective, multicenter, randomized RESTORE SVD trial, Runlin Gao, MD, professor of medicine and chief cardiologist of the Cardiovascular Institute and Fu Wai Hospital in Beijing, who presented the study at TCT 2018, and colleagues compared the Restore DCB with the Resolute Integrity DES (Medtronic) in patients with small-vessel disease.

Again, the Restore DCB demonstrated noninferiority vs. the Resolute Integrity DES in this patient population. The primary endpoint of in-segment percent diameter stenosis was comparable between patients treated with the DCB and the DES in the intention-to-treat population analysis (P for noninferiority < .001), as well as in the as-treated analysis.

In terms of angiographic results, the DCB group had smaller minimal lumen diameter (P < .001), as compared with the DES group, although late loss (P = .73) and angiographic binary restenosis rates (P = .58) were similar.

At 1 year, rates of TLF were not significantly different between patients treated with DCB compared with DES. Periprocedural MI rates were also low and comparable in both groups.

Gao and colleagues also evaluated the Restore DCB in a registry cohort of patients with very small-vessel disease. At 9 months, in-segment percent diameter stenosis was 38.4%, and TLF occurred in two patients, both of which were due to TLR.

Similar to the RESTORE ISR trial, RESTORE SVD had several limitations, including the possibility for bias due to its open-label design, the fact that it was powered for an angiographic endpoint, minimal use of intravascular imaging, and a dual antiplatelet therapy duration of at least 6 months for patients in the study.

Gao said Restore DCB has promise for use in small-vessel disease, but also called for further investigation of the device.

“An adequately powered clinical study is needed to evaluate the real clinical advantage with this new device for the treatment of small-vessel disease,” he said. – by Melissa Foster

Reference:

Chen YD, et al. Keynote Interventional Studies V: Drug-Eluting Stents, Bioresorbable Scaffolds and Drug-Coated Balloons II. Presented at: TCT Scientific Symposium; Sept. 21-25, 2018; San Diego.

Disclosures: The studies were sponsored by Cardionovum. Chen and Gao report no relevant financial disclosures.