Drugmakers have been criticized in the past for not doing enough to fight diseases of the poor as they concentrate instead on conditions more prevalent in rich nations, such as high cholesterol.
But in the largest coordinated effort yet to fight diseases such as Guinea worm disease, leprosy and sleeping sickness, the group promised to give away 14 billion doses of medicines by the end of this decade.
They will also share expertise and drug discovery work to invent new medicines for neglected tropical diseases (NTDs) that as yet have no treatments.
The AIDS pandemic forced drugmakers in the past decade to pay more attention to the developing world, and a new focus on the economic potential of emerging markets has provided an incentive to promote their brands in poorer countries.
In a project expected to affect the lives of a billion people worldwide, the partnership pledged more than $785 million to support NTD research and development (R&D) and strengthen drug distribution and treatment programs.
World Health Organization (WHO) director general Margaret Chan, who announced the deal in London, said it changes the face of NTDs -- illnesses that needlessly disable, blind and kill millions of the world's poorest people.
These ancient diseases are now being brought to their knees with stunning speed, she told an audience at the Royal College of Physicians in the British capital.
With the boost to this momentum being made today, I am confident almost all of these diseases can be eliminated or controlled by the end of this decade.
NTDs disproportionally affect people in the poorest countries of the world. Experts estimate more than a billion people are affected by them, including more than 500 million children.
Maybe as the decade goes on people will be wondering whether we should still call these diseases 'neglected', said Microsoft chairman and philanthropist Bill Gates.
The WHO's first global report on neglected tropical diseases in 2010 said that while they cost billions of dollars in lost productivity, they are often ignored because they affect mainly poor people and do not offer a profitable market for drugmakers.
NTDs include illnesses such as sleeping sickness, which is transmitted through tsetse fly bites and threatens millions of people in Africa, and Chagas disease, a debilitating condition caused by a parasite transmitted in infected feces of blood-sucking bugs. An estimated 10 million people are infected with Chagas, mostly in Latin America where the disease is endemic.
Speaking for chief executives of the drug firms involved in the partnership, Andrew Witty, GlaxoSmithKline's CEO described the impact of the diseases as horrific and said he hoped the scale of this new cooperation would beat them.
No one company or organization can do it alone, he said. It's great to have this commitment, and it's even better to have a deadline.
Adding the new pledges to existing individual commitments, 13 drug companies including Pfizer, Merck, Johnson & Johnson, Sanofi, GlaxoSmithKline, Novartis and others will donate an average of 1.4 billion treatments a year to people suffering from NTDs.
The International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) said new R&D collaborations and deals with drugmakers and the Drugs for Neglected Diseases initiative (DNDi) would also give unprecedented access to libraries of chemical compounds that may lead to new treatments.
Extra funding for the project came from Britain, the U.S. and United Arab Emirates, the Gates Foundation and the Children's Investment Fund Foundation. The World Bank agreed to extend financing to help African countries build health systems better able to integrate NTD elimination and control.
Gates, whose foundation announced a five-year, $363 million commitment to support NTD product and operational research, said the collaboration would help millions of people build self-sufficiency and overcome the need for aid and serve as a model for tackling future global development challenges.
(Reporting by Kate Kelland, editing by Ben Hirschler and Philippa Fletcher)