A new drug-releasing heart stent Johnson & Johnson (JNJ) hopes will rejuvenate its standing in the $4 billion market for the tiny devices outperformed a Boston Scientific Corp. (BSX) stent in new study data, J&J said Tuesday.

The "Nevo Res I" study will be used in a European regulatory filing, expected later this year, aimed at winning approval for the "Nevo" stent there and in other international markets that follow European rules. That suggests potential approval in 2010, which would be followed by an application for the U.S. in late 2011 pending more study data.

Nevo represents J&J's big effort to return to prominence in a heart-device market it helped develop and once led before new devices triggered substantial market-share erosion. A stent sold by both Abbott Laboratories (ABT) and Boston Scientific has significantly contributed to J&J's slide over the last several quarters.

The study data presented Tuesday at the EuroPCR cardiology conference in Barcelona covers a short time span and just 394 patients, suggesting more proof will be needed to help the device in an increasingly competitive market. But any positive developments are good for a J&J stent business that has recently been a negative weight on the conglomerate's financial results.

Wachovia analyst Larry Biegelsen said Tuesday's data "should help stabilize JNJ's (market) share and improve investor sentiment." He also said Abbott, which sells a market-leading device today, has the most to lose from the Nevo data.

The new J&J device has a design for loading medication that turns it into a bare stent over time, which may cause less irritation in heart arteries compared with stents that retain drugs and polymers used to attach drugs for a long time.

Major stent makers are taking different approaches to develop stents that mirror the performance of medicated devices in stopping arteries from reclogging, but have the long-term profile of bare-metal stents when it comes to avoiding artery irritation and late-developing clots.

Boston Scientific is developing a new generation of stents based on recently purchased "Labcoat" technology that uses a very thin biodegradable polymer for attaching drugs, for example.

The current J&J study pitted Nevo against a big Boston Scientific device, called Taxus Liberte, among patients followed for six months. The study's main goal was to measure tissue growth within the stent as tracked by an angiogram imaging system. On that measure, Nevo had an 0.13 millimeters of growth compared with 0.36 millimeters for Taxus Liberte, a difference that is considered statistically significant.

Among other performance measures tracked by the study, there was a lower composite rate of major adverse events for patients with the J&J device. J&J also noted its stent had no cases of stent-related clots, although the big concern with such clots mainly involves ones that develop after a year.

Citigroup analyst Matthew Dodds said the data "looked better than expected and point to a strong new competitor" in international markets J&J could reach next year.

Nevo's drug is loaded into tiny reservoirs rather than coated on the surface, as with the current generation of top-selling stents, and both Nevo's drug and polymer are designed to be totally gone within three months. It's thought that the drug is only needed initially.

Nevo is based on technology J&J acquired when it bought Conor MedSystems for $1.4 billion about two years ago. J&J pulled an initial Conor stent with this reservoir technology from the market when the device failed a key study, then overhauled the device and changed the drug. Nevo now uses the same drug used on J&J's "Cypher" coated stents.

-By Jon Kamp, Dow Jones Newswires; 617-654-6728; jon.kamp@dowjones.com