New find may result in single drug for TB

New find may result in single drug for TB
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First Published: Wed, Feb 18 2009. 02 54 PM IST
Updated: Wed, Feb 18 2009. 02 54 PM IST
Bangalore: The global search for a more effective drug to treat tuberculosis, or TB, may finally receive an Indian contribution, provided the pharmaceutical industry extends a helping hand to take it to the stage of clinical trials.
A team of researchers in the country has created a new compound that could lead to a single drug for TB, which is currently treated by a cocktail of four drugs, each inhibiting a single enzyme and attacking a single metabolic pathway of the bacterium that causes the disease.
The new molecule, the result of work done by Rajesh S. Gokhale of the National Institute of Immunology, or NII, in New Delhi and Rajan Sankaranarayanan of the Centre for Cellular and Molecular Biology in Hyderabad, hits four of the bacterium’s crucial metabolic pathways, leading to the pathogen’s destruction.
The scientists report their findings in the 1 February issue of the monthly Nature Chemical Biology.
“Targeting several enzymes at the same time is a much more efficient approach. Theoretically, patients wouldn’t have to take several drugs, they could just take one,” says Gokhale, who is also an international scholar at the Maryland, US-based Howard Hughes Medical Institute.
According to the World Health Organisation, TB kills about 1,000 people in India every day. The disease most commonly attacks the lungs as pulmonary TB, but can also affect the human lymphatic, circulatory and gastrointestinal systems, and bones and joints.
However, the compound developed by Gokhale and Sankaranarayanan has a problem. It is toxic for humans and needs refinement in its chemistry before it can be tested clinically. Gokhale has been knocking on the doors of the pharmaceutical industry, domestic and international, but hasn’t found patrons who could help design a less toxic version.
“This is a very good piece of work, but unfortunately, the pharmaceutical industry is not willing to take risks; this is a particularly tough time for drug development in India,” said molecular biophysicist Avadesha Surolia, director of NII.
Thirty years ago, he said, it may have been possible for Indian scientists to take their molecule to the market, but not now. “International societies have become fairly insular and promote in-house discovery…Indian companies don’t have a strategy to take up challenging tasks. They mostly want free rides of exploitation.”
Gokhale has been in talks with companies such as AstraZeneca India Pvt. Ltd, Ranbaxy Laboratories Ltd, Cadila Pharmaceuticals Ltd and Lupin Ltd, but despite initial evaluation of the compound, the work hasn’t progressed. He is currently talking to Chembiotek, the drug discovery research wing of Kolkata-based TCG Lifesciences Ltd.
Even as Gokhale examines the three-dimensional structure of the molecule to design better, less toxic molecules, he has filed for what in the patent language is called a “priority number” to protect his molecule.
“I am hopeful of striking a collaboration with Chembiotek; we could even write joint grants (the process of seeking government funds) to take this forward,” he said.
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First Published: Wed, Feb 18 2009. 02 54 PM IST