Compounds being developed against tuberculosis also show promise against deadly tropical diseases threatening millions of people, two not-for-profits groups said on Wednesday, announcing a deal to speed up drug development.

The Global Alliance for TB Drug Development has granted the Drugs for Neglected Diseases Initiative (DNDi) rights to develop a class of potential anti-TB compounds offering hope of treating Chagas disease, African sleeping sickness and leishmaniasis.

It is the "first-ever royalty-free license agreement between two not-for-profit drug developers," according to a statement from the New York-based TB Alliance and the Geneva-based DNDi about the deal backed by the Bill & Melinda Gates Foundation.

"There are innovative ways to share knowledge, to avoid duplication in research, thereby saving costs and speeding up the R & D process for the benefit of the patients," said Bernard Pecoul, DNDi's executive director.

One of the furthest advanced and most promising TB drug candidates covered by the agreement, PA-824, is in Phase II testing, the drug developers said.

The compound is from the nitroimidazole drug class. Many pathogens causing neglected diseases are susceptible to compounds in this class, they added.

Chagas, a disease caused by a parasite found mainly in rural areas of Latin America, kills some 14,000 people annually and an estimated 8 million are infected. Infection is lifelong and can lead to heart disease and heart failure. Some 100 million people are deemed at risk of the disease.

Leishmaniasis and sleeping sickness, formally known as human African trypanosomiasis, each kill roughly 50,000 people a year and pose a threat to a combined total of 400 million people.

The Gates Foundation is providing a $1.5 million grant to DNDi for preclinical assessments of compounds specifically for use against visceral leishmaniasis, a deadly parasitic infection spread by the bite of a sandfly.

Though found in Europe, Asia and Africa, leishmaniasis is most concentrated in India. An estimated 350 million people worldwide are deemed at risk from infection.