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The Dwindling Stock of Antibiotics, and What to Do About It
In an article published in Drug Discovery Today, Kinch summarized the financial constraints that have led to the current crisis in antibiotic supply. The number of antibiotics available for clinical use, Kinch said, has declined to 96 from a peak of 113 in 2000.
The rate of withdrawals is double the rate of new introductions, Kinch observed. Antibiotics are being withdrawn because they don’t work anymore, because they’re too toxic, or because they’ve been replaced by new versions of the same drug. Introductions are declining because pharmaceutical companies are leaving the business of antibiotic discovery and development. For example, Pfizer or its predecessors developed 40 of the 155 antibiotics ever sold in this country, Kinch said, but is no longer in the antibiotic business. Eli Lilly, AstraZeneca, and Bristol-Myers Squibb have also left the antibiotic field, which is now dominated by small companies, such as Cubist Pharmaceuticals, formed in 1992 specifically to focus on drugs for resistant bacterial infections that could have higher prices.
Kinch said his count, if anything, overestimates the number of antibiotics still available because some of the new drugs are not general-purpose antibiotics. They include, for example, an acne medication and a treatment for anthrax, developed for use in case of a bioterrorist attack.
One reason pharmaceutical companies are withdrawing, Kinch said, is that the U.S. patent law squeezes them for time. A patent gives a company 20 years of protection for a new drug, but it takes 11 years of clinical trial experience on average to get a drug approved. That means the typical company has nine years under patent to earn back the development costs before a generic comes in.
If the drug is an antibiotic, there is an additional catch. Because of rising resistance, doctors hold new antibiotics in reserve, using them only in cases of dire need. This happened, for example, in the case of vancomycin, which has long been used as a drug of last resort. “When you hold a drug in reserve,” Kinch said, “you're eating into the patent time a company has to recoup its development costs.”
Experts have turned to the NIH to solve the problem. But the agency’s budget, which doubled in 2009, has fallen continuously ever since. It is now 30% below 2009 levels in constant dollars, Kinch said.
Since the NIH has fallen victim to congressional gridlock, people in the biomedical community are starting to organize on their own. The group Kinch helped found, the Institute for Life Sciences Collaboration, recently convened an expert panel at the United Nations to discuss the need for innovative partnerships and financing models to deal with antibiotic resistance.
One popular idea is “de-linkage,” or finding a way to disconnect the costs of development from the sale of pills. Some have suggested that large prizes — of $1 billion or more — be offered for the development of new drugs, which would then be sold for modest prices by other companies.
The Infectious Diseases Society of America (ISDA) has launched a “10 x 20” initiative whose goal is to create global antibacterial drug research-and-development enterprise with the power in the short-term to develop 10 new, safe and effective antibiotics by 2020.
Britain is offering a prize of £10 million, called the Longitude Prize 2014 (after the prize once offered for an accurate way to determine the longitude of ships at sea), for a rapid test that would allow health professionals to identify bacteria quickly and to administer only the right antibiotics at the right time.
Antibiotics are not the only drug class heading for trouble — Kinch mentions that HIV/AIDs drugs are following a similar trajectory — but they have become the poster child for the larger problem of drug discovery and development in part because they underpin every part of modern medical practice, from surgery to cancer treatment and pretty much everything in between.