Superbug spread reveals thin pipeline of newest antibiotics3 min read . Updated: 20 Feb 2015, 11:12 AM IST
Health experts say the risk from infections of drug-resistant 'superbugs' has been growing, the pipeline of new antibiotics hasn't kept pace
New York: Every year at least 23,000 Americans die from bacterial infections that don’t have effective treatments, including two patients killed in a recent outbreak in a Los Angeles hospital that has spurred new attention on the issue.
While public health experts say the risk from infections of drug-resistant “superbugs" has been growing, the pipeline of new antibiotics to treat them hasn’t kept pace. Doctors are forced to rely on decades-old medicines with sometimes heavy side effects to treat everything from urinary tract infections to deadly hospital-acquired bacteria such as carbapenem-resistant Enterobacteriaceae, the pathogen in the Los Angeles cases.
“We have very little in the advanced-stage pipeline right now that will treat CRE," Helen Boucher, a physician and director of the infectious diseases fellowship programme at Tufts Medical Center in Boston, said in a telephone interview. “We’re forced to use, frankly, toxic drugs. We have to go in and tell patients and families that we’re going to use drugs that may poison their kidneys and have nerve toxicity."
Some 16 new antibiotics were approved from 1983 to 1987, but the rate of new drugs coming to market has fallen since then. From 2008 to 2012, just two were approved, according to a study published in the journal Clinical Infectious Diseases.
Price has played a part. While drugmakers charge more than $100,000 for the latest cancer treatments, antibiotics command far less. Cubist Pharmaceuticals Inc., an antibiotic developer bought by Merck & Co. this year, charges between $2,000 and $4,500 for its therapies. Public health experts caution against overusing new drugs, saying they could build resistance and create new superbugs.
“It’s hard to discover new antibiotics, hard to develop them and the economics are not favorable," John Rex, head of infection, global medicines development at London-based AstraZeneca Plc, said in a telephone interview last year. “All three of these are causes of our very thin global pipeline."
The Centers for Disease Control and Prevention estimates that each year at least 2 million people are infected with antibiotic-resistant bugs in the US. The National Institutes of Health Clinical Center in Bethesda, Maryland, fought its own superbug outbreak in 2011. At one point, the flagship health center’s outbreak was spreading at a rate of one new infection a week.
New antibiotics are difficult to discover. Researchers have gone to mountainsides, caves and under the sea to look for organisms that can produce antibiotic compounds. Eli Lilly & Co. at one time asked employees to bring back dirt samples from their vacations, which could be sent to the company’s labs for analysis.
Clinical trials can be problematic as well. It’s considered unethical to give a patient with a deadly infection a placebo, making it harder to test experimental treatments. And once approved, doctors and hospitals administer the newest, most powerful antibiotics only as a last resort.
“You develop a wonderful antibiotic, you show that it works, you know that the treatment course is relatively short, you know there’s a limit to what you can charge," Merck’s Nicholas Kartsonis, head of antibacterials, said. “Then somebody comes and pats you on the back and says ‘Great job, you developed a great antibiotic, now I’m going to go put it on the back of the shelf.’"
Even with the difficult economics, companies and policy makers are attempting to find new ways forward. Merck made a push into antibiotics late last year, buying Cubist for $8.4 billion and adding a pipeline of treatments that target drug- resistant infections.
The lack of new drugs has also sounded alarms in the White House and in Congress. One proposal would change the way Medicare pays for antibiotics used in hospitals, potentially removing the financial hurdles to using the drugs. Another would boost funding for antibiotic discovery to help lure in more drugmakers.
There are some promising signs that pharmaceutical companies are moving back into antibiotic development. Merck will start final-stage trials this year for a drug that treats some types of CRE infections. AstraZeneca’s antibiotic CAZ-AVI is being developed for some of the hardest-to-treat drug- resistant infections.
“Companies have started to realize that there is an unmet need," said Brad Spellberg, chief medical officer at Los Angeles County-University of Southern California Medical Center. “The industrial situation is not as dire today as it was three or four years ago. It’s nowhere near back to where it was, but we’re off rock bottom." Bloomberg