The heads of 13 of the world's biggest drug companies, brought together by Bill Gates, have agreed to donate more medicines and, in a rare spirit of co-operation, to work together to find new ones in an attempt to end many neglected tropical diseases that kill and maim some of the poorest people on the planet.

The 10 diseases targeted affect 1.4 billion people. They include lymphatic filariasis, river blindness, schistosomiasis and Chagas disease. Often the treatments that exist are ineffective, and sometimes even fatal.

The Bill and Melinda Gates Foundation is putting in $363m (£231m) over five years to fill gaps in research and drug distribution programmes for the control and, hopefully, elimination of these diseases, while the Department for International Development has announced £195m until 2015. USAid and the World Bank are also committing money and help. Endemic countries have also pledged to step up treatment.

"Maybe as the decade goes on, people will wonder if these should be called neglected diseases. Maybe as the milestones go on, we will call them just tropical diseases," Gates told the London meeting.

The most likely disease to be eliminated is Guinea worm, which has been the target of the Carter Foundation for decades. Last year, the former US president Jimmy Carter said they needed just $60m more to finish the job in the single remaining endemic country, South Sudan. That money will now be available.

The biggest contribution of the pharmaceutical companies, including Britain's GlaxoSmithKline, the US groups Pfizer and Abbott and many others, are among drug donors. Those that had donation programmes are extending them to 2020.

Unusually, some of the companies have agreed to co-operate to try to develop badly needed new drugs. Abbott, Johnson & Johnson and Pfizer are working together, under the direction of the public-private partnership DNDi (Drugs for Neglected Diseases Initiative), on new remedies for worm infections, particularly those causing river blindness and lymphatic filariasis.

All 11 companies have agreed to open up their compound libraries – details of potential drug treatments that have gone through some tests but not found a commercial use – to DNDi, which hopes effective drugs for neglected tropical diseases may be discovered. "It is a very good push in the right direction," said Bernard Pécoul, executive director of DNDi. "We have signed some very specific agreements and we have opened the door to negotiations with other partners." Sir Andrew Witty, chief executive of Britain's GlaxoSmithKline, who co-chaired the pharmaceutical round table with Gates, cited an African saying: "If you want to travel fast, travel alone – but if you want to travel far, travel in a group."

He had been "delighted at the energy we've found in the other companies", he told the Guardian.

They had all offered individual drug donations in the past, but now they had come together to work out not just what each was prepared to give, but to supply what was needed. "The biggest achievement over the last year, I think, has been to get some of the companies to really massively increase their commitments, so that everybody is kind of at this at an industrial level. I hope that what everybody is going to see today is an industry at its best, actually," he said.

The initiative is a response to a World Health Organisation roadmap – a plan to tackle diseases that impede development by preventing the poorest children from accessing education as well as limiting adults' ability to work. WHO's director general, Margaret Chan, set an ambitious timetable during the launch at the Royal College of Physicians in London.

"These ancient diseases are now being brought to their knees with stunning speed," she said. "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."

Some experts were less optimistic, however, and critical of the drug donation focus. Medécins sans Frontières (MSF), the volunteer doctors' group that helped found DNDi, said while it was delighted neglected diseases were now getting attention, WHO and others were underplaying the difficulties of eliminating some, such as Chagas disease, sleeping sickness, and visceral leishmaniasis, by 2020.

New diagnostic tools were needed to catch sleeping sickness, caused by the bite of the tsetse fly, before it became hard to treat, for example, as well as new drugs that could be used by healthcare workers with only basic training in remote areas of Chad, the Central African Republic and South Sudan. In the Democratic Republic of Congo (DRC), where about three-quarters of reported cases of sleeping sickness have been detected, funds for the strong national control programme supplied by Belgium since 1997 would be withdrawn by next year. "Nothing offered at the London NTD meeting... will address this looming crisis," MSF said.

In a letter to the Lancet, Dr Tim Allen from the London School of Economics and Dr Melissa Parker from Brunel University warned that there were problems with mass drug handouts. These included the undermining of countries' fragile health services by large internationally-funded giveaways of free drugs for all, without a great deal of evidence as to their efficacy.

"We are concerned by the way in which competition for multimillion-dollar grants is closing off debate and restricting critical analysis of what is actually occurring on the ground," they wrote.

Devastating diseases - and their treatement

• Blinding trachoma: More than 40 million people at risk and 8 million in danger of imminent blindness.

• Leprosy: 213,000 cases left in 17 countries - a 90% reduction since 1985.

• Chagas disease: Insect-borne, killing up to 50,000 in the Americas each year. Causes irreversible damage to heart, oesophagus and colon. Existing drugs inadequate.

• Sleeping sickness: Transmitted by tsetse flies in sub-Saharan Africa. In later stage, parasite invades the central nervous system. Treatment derived from arsenic kills 30% of patients.

• Leishmaniasis: Parasitic disease in 88 countries affecting over 12 million people. Few effective drugs.

• Guinea worm: Eradication campaign has been a big success thanks to distribution of pipe filters to block ingestion of worms in drinking water.

• Lymphatic filiariasis (elephantiasis): One billion at risk, mostly in tropical regions, and 40 million severely incapacitated or disfigured. Two separate drugs prevent transmission.

• River blindness: Caused by infection by the nematode worm. About 500,000 people thought to be blinded, mostly in sub-Saharan Africa.

•Schistosomiasis (bilharzia): Can cause life-threatening urinary or liver damage or cancers. Seventy-six million children need single dose treatment.

•Yaws. Non-fatal bacterial skin disease: Can lead to chronic disfigurement and disability. Cured by a single antibiotic.