Elixir Medical’s DynamX Bioadaptor Scaffold Compared to DES in BIOADAPTOR RCT

May 17, 2023—Elixir Medical Corporation announced that the BIOADAPTOR randomized controlled trial (RCT) met its primary endpoint of target lesion failure (TLF) noninferiority at 12 months for the company’s DynamX coronary sirolimus-eluting bioadaptor compared to a contemporary zotarolimus drug-eluting stent (DES). Shigeru Saito, MD, Director of the Division of Cardiology and Catheterization Laboratory at Shonan Kamakura General Hospital in Kamakura, Japan, is Principal Investigator of the trial.

The DynamX device has received CE Mark approval in Europe but is not commercially available in the United States, advised the company.

The data were presented during a late-breaking clinical session at the EuroPCR conference held May 16-19 in Paris, France.

According to Elixir Medical, BIOADAPTOR RCT is an international, single-blinded trial comparing the DynamX device with the Resolute Onyx DES (Medtronic) in 445 patients who were randomized 1:1. Both arms of the trial had large, randomized multi-imaging modality subgroups of 100 patients powered to document standard stent effectiveness benchmarks and new effectiveness benchmarks of vessel motion and function. Data collection will continue through 5 years, noted the company.

As summarized in Elixir’s press release, the DynamX bioadaptor scaffold achieved a TLF rate of 1.8% versus 2.8% for the Resolute Onyx DES (P < .001), as well as similar acute performance, acute lumen gain, and percent diameter stenosis at baseline. Additionally, the bioadaptor scaffold demonstrated normal pulsatility in the device-treated segment, confirming restoration of vessel function at 12 months.

Across components of TLF, there were no cardiac deaths in the DynamX arm and very low rates of target vessel myocardial infarction and target lesion revascularization in both arms.

The company reported that restored vessel pulsatility was demonstrated by lumen-area changes during cardiac cycle, measured with stationary intravascular ultrasound (IVUS) at multiple sections along the length of the devices and adjacent nontreated vessel segments.

At 12 months, the DynamX in-device lumen area showed an ability to significantly increase compared to postimplantation and expand by 7.5% between systole and diastole cardiac cycles, at a rate similar to nontreated segments of the vessel. By contrast, the comparator DES continued to be constrained because of caging.

For maintaining an open lumen at 12 months, the DynamX bioadaptor was significantly more effective compared to the DES, with a percent diameter stenosis of 12.7% versus 17.3% (P = .05) and a late lumen loss (LLL) significantly lower at 0.09 versus 0.25 mm (P = .038). These measures were also lower across key vessel and lesion subsets of left anterior descending artery, long lesions (≥ 23 mm), and small vessels (≤ 2.75 mm). A similar trend in low LLL was observed across vessel and lesion subsets in patients with diabetes.

Finally, a post hoc analysis of the 100-patient IVUS cohort revealed a novel finding of plaque stabilization and regression. The DynamX arm showed a 3% change of in-device plaque volume (original lesion plaque treated by percutaneous coronary intervention) whereas the DES arm showed a 12% increase (P = .032).

More than 90% of patients in both study arms were on lipid-lowering medication for secondary prevention. When lesions were analyzed for plaque composition, those with higher content of lipids showed a regression in plaque volume with DynamX compared to an increase with DES (–9% vs +10%; P = .0008), pointing to a hypothesis of a synergistic effect between restoration of vessel motion and function with DynamX and systemic use of lipid-lowering medications.

“It is widely believed that caging the vessel by stents has limited the field from overcoming the suboptimal efficacy and safety events,” commented Dr. Saito in Elixir’s press release. “The DynamX bioadaptor exceeded our expectations against a good DES in clinical outcomes, and for the first time ever demonstrated restoration of vessel pulsatility, motion, and function by uncaging the vessel. These findings establish that the bioadaptor addresses the shortcomings of DES and bioresorbable scaffolds and collectively point to a technology-effectiveness standard not seen before. The finding of plaque changes is very exciting, pointing to a new effect and potential benefit of restoring vessel function.”

Elixir Medical's DynamX sirolimus-eluting bioadaptor scaffold is constructed of three metallic helical strands joined circumferentially by a thin bioresorbable polymer coating for radial strength during implantation. After 6 months of polymer resorption, the DynamX bioadaptor is designed to unlock the scaffold, uncage the vessel, and restore and sustain normal vessel motion and function with continued dynamic support of the diseased vessel.