Abbott bioresorbable stent comparable to its drug-eluting stent in Japanese trial

Abbott's Absorb bioresorbable stent--Courtesy of Abbott

Abbott ($ABT) announced that its bioresorbable scaffold performed similarly to its traditional drug-eluting stent in a clinical trial for Japanese approval. The device is the market leader by far, and is already available in more than 90 countries, though not the U.S.

The Absorb BVS is designed to dissolve in the body after eluting everolimus, a drug developed by Novartis, for one or two years from its location in the coronary artery.

The Absorb performed comparably to Abbott's Xience drug-eluting stent, which stays in the body permanently, on metrics like target lesion failure (both near 4%) at one year, in-segment late lumen loss at 13 months (or the difference in diameter of the treated vessel 13 months after a procedure compared to a follow-up angiogram), stent thrombosis, or the formation of blood clots near the stent (both at 1.5%), and the rate of repeat procedures (both around 2.5%).

One of the advantages of bioresorbable stents is that once they dissolve, additional procedures can be performed, if necessary, while a permanent metal stent can inhibit additional intervention.

In addition, due to their temporary nature, bioresorbable stents enable the treated vessel to function naturally once again; this is known as the return of vasomotion, or the vessel's reversion to its original, prediseased state.

"Fully dissolving heart stents are the next evolution in percutaneous coronary intervention and are designed to leave nothing behind in the body, thus restoring the vessel more naturally over time, which cannot be achieved with a permanent drug eluting stent," said Dr. Takeshi Kimura, principal investigator of the 400-person Japanese trial.

Abbott has completed its filing for approval in Japan and the U.S.

Last year, Abbott announced similarly, broadly positive results from its European Absorb II trial, though some differences emerged in the latest data. One of the key takeaways from Absorb II is that doctors were cautious when using the Absorb because they were unfamiliar with the device's properties. The mean balloon pressure used was 14.23 atmospheres, compared to 15.03 atmospheres when implanting the Xience.

At that time, the consensus was that the difference in usage was not necessary. One year later, in the Japanese trial, the difference in post-dilation balloon pressure was statistically insignificant, and the devices performed similarly on the measure of in-segment acute gain, with both achieving gains of slightly less than 1.3 millimeters, according to the European Heart Journal.

In the Absorb II trial, the Absorb didn't perform as well as the Xience on acute gain in mean lumen diameter, demonstrating a mean gain of 1.15 millimeters versus 1.46 millimeters for the Xience. But, doctors analyzing the results said in a conference panel discussion afterward that they weren't too concerned by that difference, and concluded that the devices performed similarly to each other overall.

GlobalData projects the Absorb is to hit sales of $96.3 million by 2017 in the U.S. once commercialization commences.

The device is popular in emerging markets. In fact, India is its largest market right now, accounting for slightly more than a third of its $132 million in 2014 global revenues, followed by Brazil, which is responsible for more than a fifth of the total. France, Germany, Italy, Spain and the U.K. account for the rest.

- read the release
- here is the Japanese trial's study in the European Heart Journal