A court challenge to India's patent laws by the pharmaceutical giant Novartis could cut the supply of affordable medicines to treat Aids and other epidemics in the developing world, aid agencies say.
Campaigners say the wider developing world could suffer
India changed its patent laws in 2005 to comply with a global agreement on intellectual property.
A subsequent application by Novartis - one of the first under the new rules - for a patent on its leukaemia drug Glivec was rejected by India's patent office in January 2006.
Novartis is now fighting that decision, and also challenging India's patent laws, claiming that they do not comply with the international agreement.
The trial opened in Madras last month, and resumed on Thursday.
Central to the case is the question of innovation. India's patent act currently requires that drugs be "new and involve an inventive step" in order to win patent protection.
NGOs including Medecins Sans Frontieres (MSF) and Oxfam say that if Novartis succeeds, pharmaceutical firms will be able to put newer Aids treatments based on existing drugs under patent protection in India, preventing cheap generic versions being exported to Africa and elsewhere.
Pharmacy for the poor
India became the "pharmacy of the world's poor" in 1970 when it stopped issuing patents for medicines. This allowed its many drug producers to create generic copies of medicines still patent-protected in other countries - at a fraction of the price charged by Western drug firms.
But in 1994 India signed up to the Agreement on Trade Related Aspects of Intellectual Property Rights (Trips), a deal that required all WTO member countries to grant patents on technological products, including pharmaceuticals, by 2005.
Drug companies have since been queuing up to patent their brands in India. Up to 9,000 patents await examination.
Glivec was one of the first to come to court. Its patent application was rejected because it was judged to be merely a new version of an older medicine.
Novartis is now arguing that India's requirement for drugs to be new and innovative is not in line with the Trips.
Experts are divided as to whether the Glivec case would set a precedent allowing other modified drugs to be patented in India.
"There are an estimated 9,000 patent applications waiting to be reviewed, of which roughly 7,000 are believed to be modifications of old drugs," said Richard English, manager of Oxfam's Make Trade Fair campaign.
"If Novartis wins, countless medicines previously available cheaply to poor people could then be patented and priced out of reach."
Professor Brook Baker, a professor of law at Northeastern University in Boston, agrees:
"Novartis, in the underlying challenge to the patent act, is claiming that any variation of an existing entity should be patentable.
"And secondly - by inference, it doesn't directly claim so in its court papers - Novartis is also claiming that, for example, new indications or uses of existing drugs, or arguably new combinations or delivery systems of existing drugs, might also be patentable."
But Jo Walton, a pharmaceutical analyst with investment bank Lehman Brothers, said:
"My guess is that Glivec is not the best case for the Aids groups to be fighting on. I'm not sure that because you have said Glivec is novel, [the Indian government] would have to say combined [Aids] medicines and the like are novel."
MSF says it has collected 300,000 signatures in a worldwide petition calling for Novartis to drop the case.
India is home to at least five million people with HIV-Aids
The Geneva-based charity says that India's generic pharmaceutical firms are already so concerned about the challenge that they are not producing generic versions of second-line Aids drugs.
Over time, Aids patients become resistant to the antiretroviral drugs that allow them to live with the virus. New, or second-line drugs are needed, and it is these, developed after India signed up to Trips, which aid agencies are concerned would be patentable in India, should the Glivec trial succeed.
MSF says generic manufacturers have helped bring the cost of Aids treatment down from $10,000 per patient per year in 2000, to just $130 now.
Novartis, however, points out that nations are entitled to over-ride patent protection in the case of a national emergency.
Governments are permitted to issue compulsory licences which allow companies to break patent protection and reproduce drugs, for a modest royalty, when there is a public health need.
"Granting a patent to Glivec would not stop governments granting compulsory licences or getting the drugs they need for their people," said John Gilardi, a spokesman for Novartis. "This [case] has nothing to do with HIV."
However the issue of compulsory licensing is not as straightforward as Novartis makes it seem, according to Professor Baker.
"The countries that are trying to issue compulsory licences, which in some instances have been some of the more powerful middle-income countries, come under enormous pressure, and that pressure is noticed.
"Brazil has threatened compulsory licences three times. The drug companies have jumped up and down, and [the US] Congress has threatened to withdraw Brazil's trade preferences."