Medtronic will have breathed a huge sigh of relief yesterday after a US regulatory panel gave the thumbs up for approval of its drug-coated stent Endeavor.

Investor confidence in the stent’s progress was dented earlier this week, after documents published by the US Food and Drug Administration’s reviewer of Medtronic's application prior to the panel meeting suggested Endeavor (zotarolimus) could have a slightly higher association with thrombosis than Boston Scientific's marketed rival Taxus (paclitaxel).

The FDA documents indicated that, in one of pivotal studies, 0.8% of patients who received Medtronic's stent suffered a thrombosis within nine months of implantation, compared with 0.1% of Taxus patients. In addition, it also concluded that Endeavor did not perform as well as Taxus on a secondary angiographic endpoint.

Although the data had been presented before, its re-emergence for the panel meeting sparked fresh fears that Endeavor’s road to market may not be as smooth as hoped for, and the group’s stock dipped a little under 3% on the news.

Safe and effective

However, shares were on the rise again last night after news broke that the FDA's Circulatory Systems Devices advisory panel in fact voted unanimously in favour of approving Endeavor, on the basis that current data indicate that the device is safe and effective.

And Martin Leon, a principal investigator of the ENDEAVOR III and ENDEAVOR IV trials, is also confident in the device’s safety: “The Endeavor drug-eluting stent significantly reduces restenosis and the need for repeat procedures while maintaining an excellent long-term safety profile. Importantly, rates of cardiac death, myocardial infarction and stent thrombosis are exceptionally low with the Endeavor stent out to three years of patient follow-up,” he claimed, concluding: “The device’s consistently strong clinical performance will make the Endeavor stent a welcome addition to the practice of interventional cardiology in the US.”

The advisory committee did, however, recommend a post-market registry of at least 5,000 patients followed to a minimum of five years, assessing very late stent thrombosis, death and heart attack, although this is consistent with Medtronic’s proposal for a post-market study, the group said.

If Endeavor does get the final seal of approval from the FDA, it could become the first new drug-eluting stent to hit shelves since 2004, competing for a slice of the current $2 billion US market against Taxus and Johnson & Johnson’s Cypher. But there are other potential competitors looming on the horizon too, including Abbott Laboratories’ Xience V device, which could be on the market in the near future.