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Feb. 10, 2004 — Rival developers of drug-releasing stents have been battling for supremacy on the patent front. Now, there are issues of safety on the patient front as the two-way tussle moves to the marketplace.
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Boston Scientific Corp. is preparing early this year to follow Johnson & Johnson’s Cordis Corp. into the U.S. market with its own tiny, pop-up scaffolding implanted in arteries to keep them open and free of clogs.
Boston’s Taxus stent, which received approval from a U.S. Food and Drug Administration advisory panel and promising results from a clinical trial late last year, hopes for final approval so it can come out swinging against Cordis’ Cypher stent. Both stents are available in Europe but Cypher has had the U.S. market to itself since winning FDA approval last April.
Boston Scientific also lauded a U.S. court decision in November that denied Boston and Cordis’ requests for injunctions against sales of each other’s devices. The ruling didn’t dismiss patent infringement claims alleged by each side, but removed a legal obstacle to Taxus’ commercial launch. Cordis alleges that Taxus infringes on its principal patent related to balloon-expandable stents; Boston Scientific charges that Cypher infringes on a patent related to polymer coatings placed on the stent.
Meanwhile, Cordis is trying to allay concerns about Cypher’s safety. The FDA in November notified physicians it had received more than 360 reports of patients with blood clots forming around the device, with more than 60 deaths. The letter also cited more than 70 reports of possible hypersensitivity reactions, including some deaths.
The FDA had not identified a cause, and joined Cordis in advising physicians to reduce risks by making sure they select the appropriate size and correctly implant the stent. Still, the agency concluded that the rate of clotting cases is within the expected rate for any stent, and that the device is safe and effective if all instructions are followed.
It’s no surprise that every step in the process is getting scrutinized, given the technology’s high hopes — both medically and monetarily.
Like the Cypher and Taxus, the first-generation stents approved a decade ago were three-dimensional devices made via a laser micromachining process. The bare-metal stents proved promising initially, but soon ran into some problems. Within about six months, about 30 percent to 35 percent of arteries with implants would renarrow and reblock because of scar tissue. By adding a drug that is released from within special polymers placed on the stent, the rate of renarrowing, or restinosis, drops to between 5 and 10 percent — reducing or preventing the need for heart surgery.
The U.S. stent market is expected to grow from about $2.5 billion in 2003 to $4.5 billion in 2005, with $4.4 billion of that coming from drug-releasing stents. The growth comes from higher prices and rapid adoption of the new stents, according to Waltham, Mass.-based Decision Resources.
Decision Resources analyst Heather Martin said it’s too early to predict a winner in the multibillion-dollar market, though it’s better served by more competition.
“Boston Scientific will definitely take market share away from the Cypher stent — without a doubt,” she said. “They’ll be neck-and-neck. Time will tell which will prove to be the best.”
Martin said success ultimately will come down to who has the better price and safety profile, but those likely will be moving targets for a while. Cordis launched Cypher at $3,195 but that should drop to $2,500 in the next two years — spurred in large part by competition — though Boston has yet to disclose a price for Taxus.
The safety issue may seem to favor Taxus, but that, too, is premature, according to Dr. Steven Werns, director of invasive cardiovascular services and professor of medicine at the University of New Jersey’s Robert Wood Johnson Medical School. He said the FDA communiqués regarding the Cypher created unjustified alarm among patients, and that the rates of clotting have been acceptable and often explainable. The three cases he has been involved with were related to patients who didn’t take required drugs after the implant — something that could happen with a bare-metal stent.
He also said some clotting is likely with Taxus stents as well. “It’s probably unavoidable — these are events that occur at a rate of 1 percent or less.”
Werns has not been involved in the Taxus trials, but he’s followed the news and plans to test it as soon as he can. “My feeling is (Cordis) has achieved low restinosis, but not all patients are candidates for their stent. I’m hoping we can put a lot more of them in.”