The first experimental drug that fights both conventional and drug-resistant forms of tuberculosis is advancing to late-stage clinical testing, researchers said, raising hope for a new way to stem the growing threat of drug-resistant TB.
The trial, financed in part by the Bill & Melinda Gates Foundation, will test the safety and effectiveness of a new three-drug cocktail known as PaMZ that in mid-stage testing helped to significantly reduce treatment times.
In a statement announcing the trial, Microsoft co-founder Bill Gates, co-chair of the Gates Foundation, said the treatment could "reduce the time required to cure drug-resistant TB from two years to just six months" and sharply cut the cost of a cure in low-income countries. He called on other funding groups to back the trial, which is estimated to cost $US58 million.
The World Health Organisation estimates that 8.6 million people developed TB in 2012 and 1.3 million died from the disease. According to the WHO, half a million people became sick with dangerous superbug strains of tuberculosis in 2012, and as many as 2 million people worldwide may be infected with drug-resistant TB by 2015.
The trial, set to begin in November, will span some 50 study sites across Africa, Asia, Eastern Europe and Latin America.
If successful, the oral treatment would eliminate the need for injectable drugs and reduce the cost of multiple-drug-resistant TB therapy in some countries by more than 90 per cent in those patients whose TB is sensitive to the three drugs.
The therapy also promises to be compatible with commonly used treatments for human immunodeficiency virus or HIV, helping the millions of people infected with both TB and HIV, the virus that causes AIDS.
Jan Gheuens, who manages the TB drug program for the Gates Foundation, said the study's results could be ready by 2017, and if the findings are positive, approval could be expected by the end of 2018.
Dr Mel Spigelman, chief executive officer of the TB Alliance, a non-profit research group that will conduct the study, said the treatment will only be effective in about a third of patients with multiple-drug resistant TB or MDR-TB.
But even at that rate, he said the therapy could help "revolutionize" treatment because currently, only about 15 percent of patients with MDR-TB get treatment, and only half of those are cured.
Standard treatment for TB usually includes a mix of four drugs over a period of six months. MDR-TB can take 18 to 24 months to treat.
The trial announcement followed the successful approval of Johnson & Johnson's drug, bedaquiline, in 2012 for the treatment of drug-resistant TB. This was the first new TB drug in more than 40 years.
Last fall, the European Medicines Agency's Committee for Medicinal Products for Human Use recommended granting conditional marketing approval for delamanid, a treatment for drug-resistant TB being developed by Japan's Otsuka.