Wednesday, May 20, 2009

A NEW GENERATION OF DES-THE NEVO STENT

The EuroPcr has just started in Barcelona. This is probably the second largest interventional cardiology meeting in the world, after the TCT. It is held every year at Barcelona ( previously it was held in Paris ). The meeting started on 19th May 2009.
One of the first clinical trials presented at this year's EuroPcr was the NEVO RES-ELUTION 1 study. This is a very interesting study, because it is very much a proof of concept. Years ago, JnJ bought a company which manufactures the Conors costar stent. The Conors stent had a very unusual design in that the stent itself has pits ( wells ) in it, which allowed drugs to be used to fill the well, almost like a stent depot with drugs eluting at programmed intervals, which hopefully will fight restenosis in particular and CAD in general. I remember the early days when we had meetings on this stent platform and we were all postulating how usueful this stent platform was, imagining that we could fill it with aspirin, statins, anti-proliferating drugs, steriods, estrogens, and all kinds of other drugs were being suggested.
At last all was not to be. Conors started a clinical trial with this costar stent platform and filled it with paclitexal, and the trial results were disasterous. JnJ bought over the company, just before the results were announced. And when the results were poor, JnJ pulled costar off the amrket, and has been struggling to keep up with the second generation DES since.
Well, it looks like they have not been complacent. They have now sponsored a study called the Res-Elution 1 study, which uses this conors pit-technology on a new stent platform, a cobalt chromium platform, They call this new stent, the NEVO stent and filled the pits ( wells ) with their own sirolimus ( many of us feel that the limus-line is the way to go ), and an erodable polymer. Of course to show that they are good, and better, they compared the Nevo DES with Taxus liberte ( to many of us, the taxus stent, with paclitexal as the drug, is probably the weakest of the DES that we have around ). So JnJ organised a trial, single arm, non-blinded, of Nevo vs Taxus liberte, on a non-inferiority basis. About 400 patients were studied over six months. Late loss ( our way of measuring tissue regrowth in the DES ) at six months was the primary end-point. It is not difficult to predict that Nevo came out better than Taxus. I wonder what will happen if they had compared it with their own Cypher stent or the latest Xience V stent. Well, no body wants to lose twice, so comparing with Taxus makes marketing sense.
Of course, for us clinicians, it is very much a proof of concept. At least they have proven that thepit technology is no harmful, and may work well, if given the right stent base, and reight compounds. I hesitate to call this the Third Generation as many of us will need to see large scale clinical trials to compare the Nevo stent against other DES, and also using clinical endpoints like MACCE as their primary endpoints. Also a longer duration like 9 months to a year, and if possible two to three years, would even be better.
For the moment, the Nevo stent looks promising, and we await more data. For us old-timers, it is good to know that the second generation DES is being improved and better stents are on the way.

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