New Coronary Implant Unlocks Vessel Motion and Improves Outcomes
The bioresorbable polymer-based implant has the potential to revolutionize the field of vascular interventions.
May 18, 2023
Elixir Medical may have found the holy grail of vascular restoration.
Late-breaking data presented at EuroPCR 2023 in Paris, France this week showed that Elixir's DynamX Coronary Drug-Eluting Bioadaptor restored vessel function at 12 months.
DynamX Bioadaptor scaffold is formed from three metallic helical strands joined circumferentially by a thin bioresorbable polymer coating to provide radial strength during implant. Following polymer resorption after six months, the DynamX Bioadaptor is the first coronary implant technology designed to unlock the scaffold, uncage the vessel, and restore and sustain normal vessel motion and function after percutaneous coronary intervention (PCI) with continued dynamic support of the diseased vessel. With this unique mechanism of action, the Milpitas, CA-based company said the device is intended to address the shortcomings of drug-eluting stent (DES) and bioresorbable scaffolds while delivering sustained low clinical event rates.
In the BIOADAPTOR RCT study, the device demonstrated superior effectiveness of its unique mechanism of action across secondary intravascular imaging endpoints, achieving restoration of the vessel motion and function compared to persistent constraint with DES.
The trial compared the DynamX Bioadaptor to Medtronic's Resolute Onyx drug-eluting stent (DES). DynamX met its primary endpoint of target lesion failure (TLF) non-inferiority at 12 months. The bioadaptor scaffold achieved a very low 1.8% TLF rate compared to 2.8% for Resolute Onyx DES (p
“It is widely believed that caging the vessel by stents has limited the field from overcoming the suboptimal efficacy and safety events,” said Shigeru Saito, MD, principal investigator and director of the division of cardiology and catheterization laboratory at Shonan Kamakura General Hospital in Kamakura, Japan. “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.”
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.
“We're humbled. After over 10 years working on this technology, we’re humbled to see the results and validating all that the world has been looking for,” Elixir Medical CEO Motasim Sirhan told MD+DI. “And that is really vessel restoration and the impact that it brings in elevating the standard of care in terms of safety, effectiveness to a level that has been unseen in PCI to date.”
The BIOADAPTOR RCT is an international, single-blinded, randomized controlled (1:1) trial comparing a sirolimus-eluting Bioadaptor with a contemporary zotarolimus-eluting stent in 445 patients. Both arms had large randomized multi-imaging modality subgroups of 100 patients powered to document standard stent effectiveness benchmarks, and the new effectiveness benchmarks of vessel motion and function. Data collection will continue through five years.
Device effectiveness and vessel function results:
Restored vessel pulsatility – Lumen area changes during cardiac cycle were measured with stationary intravascular ultrasound (IVUS) at multiple sections along the length of the devices and adjacent non-treated vessel segments. At 12 months, the DynamX in-device lumen area showed ability to significantly increase compared to post-implant and expand by 7.5% between systole and diastole cardiac cycles, at a rate similar to non-treated segments of the vessel, while DES continued to be constrained due to caging.
DynamX Bioadaptor was significantly more effective at maintaining an open lumen at 12 months compared to DES with percent diameter stenosis (%DS) at 12.7% vs. 17.3% (p=0.05) and late lumen loss (LLL) being significantly lower at 0.09mm vs. 0.25mm for DynamX and Resolute Onyx, respectively (p=.038). These measures were also lower across key vessel and lesion subsets of LAD, long lesions (≥23mm) and small vessels (≤2.75mm). Similar trend in low LLL was observed across vessel and lesion subsets in patients with diabetes.
Novel finding of plaque stabilization and regression:
In a post-hoc analysis of the 100-patient IVUS cohort, the DynamX arm showed only a 3% change in in-device plaque volume (original lesion plaque treated by PCI) while the DES arm showed a significantly higher 12% increase (p=0.032). Over 90% of the patients in both study arms were on lipid lowering medication for secondary prevention. When lesions were analyzed for plaque composition those that had higher content of lipids showed a regression of -9% in plaque volume with DynamX compared to an increase of +10% with DES (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.
BIOADAPTOR RCT is the third trial of Elixir'd DynamX Bioadaptor clinical evidence program consisting of nine company sponsored and investigator-initiated studies involving more than 9,000 patients, including INFINITY SWEDEHEART RCT (n=2400) and a global BIO-RESTORE registry with a target enrollment of up to 5,000 patients.
"The Bioadaptor is a unique technology that is a metallic-based frame that is composed of three helical strands that are joined circumferentially temporarily, but actually connected. And there is a thin polymer coating that is resorbed at six months," Sirhan told MD+DI. "And when it's resorbed at six months, it allows the implant to unlock and allows the implant to circumferentially uncage the vessel. Therefore, restoring pulsatility and restoring vessel motion and function. And for the first time, a technology was able to demonstrate that because of the unique properties of the Bioadaptor."
Vascular device companies have widely recognized the need to "uncage" the vessel to improve long-term outcomes. But designing a device to successfully do so has been easier said than done. Bioresorbable scaffolds were valiant effort, but ultimately fell short on acute performance and on vessel restoration, Sirhan said.
"One of our unique properties of the Bioadaptor is that after it uncages the vessel, there is a support system in place to carry the load of that disease that have accumulated over the years. And therefore, being able to see the full restoration of pulsatility leading to complete vessel function, normal vessel function and motion," Sirhan said. "That was remarkable to see in the study and it really opened our eyes when that happened."
Sirhan said Elixir is also conducting a 2,400-patient trial, randomized 1:1 against the Resolute Onyx. That trial is almost completed, he said. The company is also planning a 5,000-patient registry, and an investigational device exemption study in the United States, which is expected to being enrolling patients early next year.
The Bioadaptor has a CE mark and Elixir is beginning commercial and market development activities in Asia, parts of Europe, and in the Middle East. Sirhan said the company also expects to file for Japanese approval based on this new data sometime this year.
"Another important indication we are extremely excited about in the next year or two, there will be the opportunity for patients who have vulnerable plaque," Sirhan said. "These are patients who have plaque in their vessels accumulating. And they are not necessarily going to be responding to statins because of the vessel becoming dysfunctional over time, because of that plaque burden. The dynamics could be potentially uniquely suitable to address that large patient populations by being able to restore that vessel functionality and allowing the vessel to respond to systemic drugs like statins in a very synergistic manner."
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