Every year, 2 million new cases of TB occur in India. It is a disease that is fully curable, yet many succumb to it while others develop drug-resistance.
A person with multi drug-resistant TB (MDR-TB) is not responsive to at least one of the two main TB drugs. Drug resistance is a consequence of misuse or mismanagement. It occurs when patients do not complete their treatment or frequently miss doses in between. It can also occur if the wrong dose of medication is prescribed or there is inadequate access to medicines. It is estimated that MDR-TB is found in nearly 3% new TB cases and between 12%-17% of re-treatment cases. Given the significant burden of TB in India, this translates into large numbers in absolute terms.
The conventional treatment regimen for MDR-TB... involves the administration of a cocktail of medicines and injections over 18-24 months.
The conventional treatment regimen for MDR-TB is extremely complex. It involves the administration of a cocktail of medicines and injections over a period of 18-24 months. The second-line drugs that are given to patients who are unresponsive to first-line treatment have numerous adverse side-effects for long periods of time. As a result, adherence to the treatment regimen is very poor. Many patients stop taking medication or are lost to follow-up by the health system.
The World Health Organization has recently recommended a new treatment protocol which is commonly referred to as the Bangladesh Regimen. It can be completed within 12 months, which not only reduces costs but also has the potential to improve treatment outcomes. This regimen is suitable for patients who have uncomplicated MDR-TB and are responsive to second-line medication. The shorter regimen has been evaluated by programmatic studies in 10 countries globally involving approximately 1,200 patients.
[T]he Bangladesh Regimen can be completed within 12 months, which not only reduces costs but also has the potential to improve treatment outcomes.
In India, too, a number of studies are underway to evaluate the efficacy of novel combinations of drugs for MDR-TB. In one study, patients are being put on the conventional 24-month regimen along with others who are being given a promising new drug, Bedaquiline. A separate study is assessing the Bangladesh regimen. TB Alliance has also developed a shortened regimen called PaMZ which has shown encouraging results thus far. A study evaluating PaMZ is currently underway and it is expected that patients from five states in India (Delhi, Gujarat, West Bengal, Tamil Nadu and Maharashtra) will be enrolled for this. If the study is successful, injections will not be needed and the cost of MDR-TB treatment will be reduced by over 90% in patients who are sensitive to the three drugs in the PaMZ combination.
Given the significantly high burden of TB and MDR-TB, as well as the challenges associated with ensuring that all patients comply with their treatment for long periods of time, it is vital for India to assess shorter, more cost-effective regimens. As India is also a very large and diverse country, studies for evaluating the efficacy of new drug therapies must be carried out in different settings to develop a robust evidence base for the impact of these regimens on reducing TB related mortality and morbidity.