April 20, 2024

F.D.A. Approves Drug to Treat Hospital Scourge

Dr. Gorbach ended up devoting much of his career to tracking down the cause of that outbreak and pursuing treatments. On Friday, 40 years after he began his quest, the Food and Drug Administration approved a drug he helped develop.

The drug, called Dificid, is the first new medicine in 25 years approved to treat diarrhea caused by Clostridium difficile, a nasty and persistent bacterium that one study suggests may have surpassed the better known MRSA as the leading hospital-acquired infection.

In clinical trials, Dificid, also known as fidaxomicin, proved better than the only approved drug in keeping patients free of symptoms 25 days after the end of treatment. The new drug was developed by Optimer Pharmaceuticals, where Dr. Gorbach, now 76, is the chief scientific officer.

Infections and deaths from C. difficile — the name means “difficult” — have increased sharply since the 1990s, in part because of the spread of a more virulent strain. It is estimated that several hundred thousand Americans are infected each year. Up to 1 percent of patients must have their colons removed and about 5 percent die.

While most of those infected are elderly people in hospitals or nursing homes, younger adults and children can also be infected, and there are cases that arise outside the hospital.

Problems usually start when people are treated with antibiotics for some other infection. That can kill off many of the harmless bacteria in the intestines, allowing C. difficile, which is resistant to most antibiotics, to take over.

Two drugs are now used to treat C. difficile, one of which — metronidazole, a generic antibiotic also sold by Pfizer as Flagyl — was never actually approved for this use. The other is Vancocin, an oral form of the antibiotic vancomycin, which is sold by ViroPharma and was approved in 1986.

While the drugs usually clear the diarrhea, it can come back, often more than once.

“When patients get better and are discharged and have another recurrence, it sets them back to Square 1,” said Lynne V. McFarland, an expert at the Puget Sound veterans affairs hospital in Seattle.

Dificid might help reduce those recurrences.

In two clinical trials involving a total of about 1,100 patients, both Dificid and Vancocin cleared the diarrhea in more than 85 percent of patients by the end of the 10-day treatment period. But in later weeks, roughly 25 percent of the Vancocin users had a recurrence compared with only about 15 percent of the Dificid users.

The net result was that 25 days after the end of treatment, about 70 percent of those treated with Dificid were still free of disease compared with 57 percent of those treated with Vancocin, according to Dificid’s label.

The main side effects are nausea, vomiting, abdominal pain and gastrointestinal hemorrhage.

Dificid is the first approved product for 13-year-old Optimer, which is based in San Diego. Cubist Pharmaceuticals will help market the drug, which is a tablet taken twice a day.

Eun K. Yang, an analyst at Jefferies Company, has predicted annual sales could reach $159 million by 2015.

Vancocin had sales of $259.6 million in 2010, up 22 percent because of price increases, while the number of prescriptions declined. ViroPharma has said that C. difficile infections in the United States may have leveled off or declined since 2008.

Optimer declined to disclose the price of Dificid until a conference call with analysts on Tuesday. But the drug is likely to be at least as expensive as Vancocin, which costs $1,000 or more for a course of treatment.

A high price might limit Dificid’s use to the most severe cases. Generic versions of Vancocin could be approved in the coming year, which would hurt sales of Dificid.

For Dr. Gorbach, the approval was a coda to a career spent mostly as a professor of medicine and public health at Tufts University.

It was there that he and colleagues identified toxin-producing clostridia as the culprits in the New Zealand outbreak. Upjohn, the manufacturer of the antibiotic involved, paid for the research. The finding was published in The New England Journal of Medicine in 1978.

In 2003, Dr. Gorbach was asked for advice by another pharmaceutical company, Optimer. He grew excited when he learned that hamsters treated with fidaxomicin had remained healthy even after treatment stopped.

“All the other drugs, when you stop the treatment, they all die within two or three days,” he said.

In 2005, while keeping his post at Tufts, he joined the company.

“This was an opportunity for me to see a drug through that could really make a difference in people’s lives,” he said. “It’s thrilling to be part of this and see the full circle.”

Article source: http://feeds.nytimes.com/click.phdo?i=2c273d96bee508f20d1ece68c9afd191

Speak Your Mind