Tuberculosis (TB), a raging problem in Europe and Americas till early 20 century, now predominantly affects the developing world where it continues to be a major health problem and is making in roads even into the developed world. Globally, a TB associated death happens every 20 seconds. India has 20 per cent of the global burden of TB. TB is one of the leading causes of mortality in India, with nearly 1000 deaths a day.
The firstline treatment for TB comprises of Rimpampicin, Isoniazid, Pyrazinamide and Ethamabutol adminsitered in combination for 6- 9 months, delivered under the DOTS programme. The duration of the treatment and the side effects of the drugs are major reasons for non-compliance which in return catalyses the emergence of Multi Drug Resistant (MDR) and Extremely Drug Resitant (XDR) strains of TB. In such drug resistant cases we have to rely on a regimen of drugs which are not only less effective but are also significantly more toxic and to top it all have to be administered for extended period up to 18 months.
The recent reports of extreme varieties of XDR TB from Mumbai raise an alarm bell. Co-morbity situations like TB with HIV or TB in diabetic patients, both of which are prevalent in India, make treatment even more complex. Thus there is an urgent need to introduce not only new TB drugs but also new regiments that are effective and can also reduce the duration of therapy.
Lack of innovation
There is a serious lack of innovation of new drugs in TB as no new drugs have been introduced in the last 50 years. This is because of the lack of a sizable market attractive for the large pharmaceutical companies to invest. The global TB drug market is estimated to be only US$ 300-400 million while the cost of discovery and development of a drug is estimated to be manifolds of this figure.
In the absence of market incentives, we need to have novel models of innovation to drive research on TB. Public sector research institutions and hospitals have a leading role to play. Public funds are required to be committed to drive research. The Global Alliance for TB (GATB) has been successful in building a pipe line of novel drugs and combinations for TB treatment. The Open Source Drug Discovery (OSDD) initiative of the Council of Scientific and Innovative Research (CSIR), with its first target disease as TB is a working example, which connects a large number of institutions in public and private sector, to promote innovation in TB drug discovery.
OSDD in collaboration with GATB is initiating clinical trials of new drugs and combinations for the treatment of MDRTB patients in India. This model of increased public sector participation in discovering, developing and making the drug available to the patient at affordable prices perhaps is the only way to find new cures for neglected diseases.
(Prof Brahmachari is Director General, CSIR, with inputs from Tanjore S Balganesh and Zakir Thoma, CSIR OSDD)
