The reason may be related to manufacturing issues at Johnson & Johnson's Cordis Corp. unit, which is being closely monitored by the Food and Drug Administration. In April, the agency sent a scathing letter citing numerous problems it called ''serious violations of the law."
Doctors say they continue to face shortages of Cordis's drug-coated Cypher cardiac stent and that, as a result, the company is failing to regain lost market share. Stents are tiny wire mesh tubes used to prop open clogged coronary arteries. Cypher and Boston Scientific's Taxus are the only two drug-coated stents on the market, considered a major medical advance because it reduces scar tissue that can block arteries again.
After launching in March, Taxus quickly dethroned Cypher, capturing more than 70 percent of the market, according to Boston Scientific. But starting in July, Boston Scientific has had to recall 99,200 stent systems because of a manufacturing defect that made it hard in some cases to deflate the balloon used to implant the stent. The defect has been linked to three deaths and 47 serious injuries. The Natick company said it has fixed the problem and that it has been able to keep more than 60 percent of the market.
Industry analysts blame Cordis's manufacturing woes for the shortages.
''This is an opportunity to mend fences, and they're really not exploiting it," said Bruce Cranna, medical-device analyst for investment banker Leerink, Swann & Co. in Boston. Added Merrill Lynch analyst Daniel T. Lemaitre: ''You hear reports of shortages, and you scratch your head. You wonder how they can still have problems keeping up?"
Cordis spokesman Martin Schildhouse yesterday said the FDA's warning letter ''does not impact our ability to supply the market." Asked about doctors' complaints of shortages, he wrote in an e-mail: ''Due to physician preference and recent market events, we are continuing to ramp up production to meet the increased demand for the Cypher stent."
The FDA letter, dated April 1, was sent to Cordis Cardiology president Richard D. Anderson. ''FDA is concerned with the breadth and scope of the specific violations noted in this letter . . . which we believe are symptomatic of serious underlying problems in your firm's manufacturing and quality systems," the letter states.
The problems were found during inspections of Cordis facilities in Warren, N.J.; Miami Lakes, Fla.; Puerto Rico, and Europe. They were so serious the FDA said the Cypher stents being produced were considered ''adulterated."
Among other things, the letter said that at a plant in Puerto Rico, a batch of product that had failed to meet a quality standard was later resampled, retested, and passed for distribution. The letter also described cases in which Cordis failed to properly track complaints about problems with the stents, such as blood clots they may have caused. For instance, several hundred complaints from 2002 and 2003 in Europe were not fully investigated at the time of the inspections, the letter states.
The FDA demanded a comprehensive response plan, and said it might seize the stents or issue fines.
FDA officials were unavailable to comment yesterday, a spokeswoman said. Cordis won't say how it responded to the FDA warning letter or release the review plan the agency requested.
Cypher supplies may also be thin because Cordis imposed a three-month shelf life on its drug-coated stents, even though the FDA approved a six-month shelf life, said doctors who deal with Cordis. The drug-delivery characteristics of the stents change over time, and the self-imposed three-month expiration date limit is intended to ensure Cypher stents stay well within government parameters, these people say.
The downside, doctors said, is that Cordis ends up discarding a lot of stents, making it even harder to keep Cypher stents in stock. Asked about the new limit, Cordis spokesman Schildhouse wrote: ''I cannot speculate on the packaging." Whatever the reason, some Cordis customers are miffed by the low inventories.
At Duke University's medical school, director of interventional cardiology Peter Berger said he would prefer to avoid using the drug-coated Taxus stent until it becomes more clear that Boston Scientific has solved the problem.
But he still uses Taxus when Cordis can't supply the right size or length of stent.
''It's beyond me why the supply problem hasn't been solved yet," Berger said of the manufacturing difficulties, adding the issue ''has angered some customers who are all the more willing to use Taxus."
Daniel Simpson, director of the cardiac catheterization laboratory at Walter Reed Army Medical Center in Washington, D.C., said he's never been able to get enough Cypher stents since they were introduced in early 2003. Often the stents he can get are the wrong sizes for his patients. ''It's been a continual problem," said Simpson.