Preparing a culture of TB bacteria

WHO/TDR/Crump

[NEW DELHI] Indian researchers have discovered a new molecule that they say could lead to a faster cure for tuberculosis (TB). They have applied for clearance to perform human clinical trials on the potential drug and for patents both in India and in the United States.

The molecule has been tested in rats and in guinea pigs, where it reduced the normal treatment time of six to eight months to just two months. In addition, it was found to be effective against all known drug-resistant strains of the bacterium that causes TB.

Indian science minister Kapil Sibal announced the results on Monday (6 September). Raghunath Mashelkar, director general of the Council of Scientific and Industrial Research (CSIR), which participated in the study, says this is the first time in 40 years that a TB drug candidate has shown promising results in animal studies.

Mumbai-based Lupin Laboratories identified the new molecule in 2001. In subsequent cell-based and animal studies, researchers found that it significantly reduced numbers of TB bacteria. When given in combination with other TB drugs, it cleared TB bacteria in animal lungs and spleens within two months. 

Over the course of six months, the scientists found no evidence that the bacteria developed resistance to the drug. The researchers observed no adverse effects on tested animals whether the molecule was given in single or multiple doses, and a single oral dose given daily was effective.

The proposed human trials would study whether the molecule could work as a stand-alone drug, or substitute one or two components of the present four-drug cocktail, says Sudarshan Arora, of Lupin Laboratories. 

The current anti-TB treatment lasts six to eight months and is effective only in an uninterrupted schedule. In many resource-poor countries, patients often skip their doses, which makes multiple drug resistance more likely.

Some 1.6 billion people (almost one-third of the world population) are infected with TB, with eight million new cases occurring each year. The current global market for TB drugs is estimated at US$600 million.

A consortium of 12 government research institutes and universities joined Lupin Laboratories to develop the molecule. They included three CSIR laboratories: the Central Drug Research Institute in Lucknow, the Indian Institute of Chemical Technology in Hyderabad, the National Chemical Laboratory in Pune, and the University of Hyderabad.