The advocacy effort turned the spotlight on half a dozen diseases that hit poor countries in particular and for which new drugs, tests and vaccines are urgently needed.

It said that three billion dollars a year were needed for research in these diseases, a drop in the ocean compared with the more than 106 billion dollars annually spent on health research around the world.

The list of research "orphans" is headed by AIDS, malaria and tuberculosis (TB).

These three are well-known diseases whose cause has been taken up by the Global Fund, which focuses however on distributing the drugs to combat them rather than on researching new ones.

In addition, most of the existing treatments are inadequate or at risk of drug resistance as the pathogen mutates. And they sometimes require a complex regimen of pill-taking.

Another problem is that vaccine research into all three diseases is meagre, given the poor incentive for pharmaceutical giants to get involved in prevention rather than treatment.

Other neglected diseases named by the campaign are sleeping sickness, leishmaniasis and chagas disease, which are rampant in poor tropical countries of Africa or Latin America.

The campaign is spearheaded by a Geneva group, Drugs for Neglected Diseases Initiative (DNDi).

"Of the 1,393 new medicines approved between 1975 and 1999, only one percent was developed for tropical diseases and tuberculosis," it noted.

The year-long campaign was kicked off in London a month before the Group of Eight (G8) summit in Scotland, but was also given regional launches in the bid to get maximum impact.

Signatories include 15 Nobel winners, including medicine laureates John Sulston, peace prizewinners Desmond Tutu and Jose Ramos Horta and authors Dario Fo and Nadine Gordimer.

A roster of leading medical research institutes and non-governmental organisations (NGOs) are also lending their support, such as France's Pasteur Institute, Medecins Sans Frontieres (MSF, Doctors Without Borders) and Oxfam.

Philippe Kourilsky, director of the Pasteur Institute, said the initiative was not just a banging of the drum for more cash and political support.

It also called for fresh thinking on how research funds, knowledge and intellectual rights are shared, for many discoveries are made in labs but are never exploited because there is no commercial gain or there are fears that to share them could help a rival, he said.

"To develop a new drug costs around half a billion euros (625 million dollars) if setbacks are factored in," Kourilsky said in Paris on Monday.

"So if you want to develop 20 drugs, you are talking about colossal sums that are beyond the reach of NGOs and private institutions and will even strain international institutions. We have to do more with less money," he said.

MSF pitched for money to go into new diagnostic tools, another area often snubbed by Big Pharma.

"Determining whether a patient has tuberculosis or not with the existing diagnostic test only works about half of the time," said MSF's Tido von Schoen-Angerer.

"For children or people co-infected with TB and HIV, the test is even more unreliable. There is no simple effective test to diagnose and follow up these patients today."

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