The US is bearing a disproportionate share of drug R&D costs for medicines used globally at the same time that price controls in other industrialised nations are leading more US residents to obtain unregulated drugs elsewhere, Food and Drug Administration Commissioner (FDA) Dr Mark McClellan has claimed.

Speaking at the First International Colloquium on Generic Medicine in Cancun, Mexico, McClellan called for more equitable cost sharing and price setting. "If we do not find better ways to share the burden of developing new drugs and biologics, all of us will suffer," he said.

"The benefits of these treatments are global, and so if we think only of the short-term interest of our own country, we all lose the opportunity for a healthier world. The heart of the problem is that we are not all paying our fair share of the costs of bringing new treatments to the world. And this problem is getting worse."

McClellan's talk comes as drug price control is increasingly becoming a political issue. The governor of Illinois is exploring whether the state can save money if health plans let retirees and state employees obtain prescription drugs from Canada, following the example of Springfield, Massachusetts, which has implemented a similar voluntary program for city employees and retirees.

Massachusetts has also launched a lawsuit against 13 makers of generic drugs, alleging that over several years they inflated prices of medicines bought by the state's Medicaid program by more than US$50 million. The World Trade Organisation has recently taken on the issue of prices as well, agreeing to let developing countries import less-expensive generic drugs to fight deadly diseases such as AIDS.

One common estimate is that it costs US$800 million to develop each new drug, and that of every 5000 to 10,000 compounds screened for development, 250 go to pre-clinical testing while five actually move to clinical testing and one winds up going to the FDA for approval, McClellan said. If drug developers have no guarantee they will recoup the expense, they have no incentive to produce new drugs, he said.

"We've seen this problem in new treatments for the agents of bioterrorism. There is no natural 'market', so product developers have to depend on whatever governments are willing to pay. And as a result, the treatments available to prevent bioterrorist diseases like smallpox haven't really changed in decades," McClellan said. "If holding a patent for a new and innovative product does not mean that this value to world health can be recovered, that means less development of new treatments and less improvement in world health."

So nations must find better ways to share the costs of developing new drugs and biologics or "all of us will suffer," he said. "The benefits of these treatments are global, and so if we think only of the short-term interest of our own country, we all lose the opportunity for a healthier world. The heart of this problem is that we are not all paying our fair share of the costs of bringing new treatments to the world. And this problem is getting worse."

US residents pay for about half of all pharmaceutical spending globally, though they "account for a fraction of prescription drug use worldwide," he said, adding that Germans will pay less than 5 per cent and "the same kind of drug payment disparity is true for many other developed nations who have about as much ability to pay as Americans do."

One possible way to change the situation could be for drug prices to be set in proportion to a nation's income. "Developing nations should pay little; rich nations would pay more to support the research and development. If all of the developed countries share this burden together, none need to stuck with very high prices," he said.

The speech is meant to be a call for international discussion of price control and development cost issues, said McClellan, who is both a medical doctor and an economist.

"With more promising new treatments in the pipeline than ever, I don't believe the billions of people around the world who are suffering from diseases today that may be treatable in the near future can wait," McClellan said. "It is time for developed nations, recognising their shared interest in bringing better treatments to market, to work together to find ways to fairly share the cost -- not just the benefits -- of new drugs."