More affordable treatment for latent TB infection by novel combination drug

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Last Updated on November 20, 2019 by The Health Master

Mumbai: A simpler, novel and more affordable treatment for latent tuberculosis infections is on the way in a country which has the highest incidence of the disease in the world: leading to an over 60% reduction in medicine usage. Mumbai-based Macleods Pharma is set to become the first company globally to launch a novel fixed-dose combination drug to prevent latent tuberculosis infection from progressing into an active one. Significantly, the combination drug has been recommended for preventing latent TB infection in two specific groups: people living with HIV (PLHIV), and household contacts, in high TB countries.

With this new drug, a substantial part of the population exposed to latent TB infection, household contacts will also be able to access treatment. Household contacts, basically people who can be exposed to TB in normal settings, are now advised by WHO to take TB preventive therapy.

At present, a single drug, Isoniazid, is the standard treatment for LTBI (latent TB infection), taken daily for six to nine months, but only for PLHIV. The other regimen involves taking two drugs, Rifapentine and Isoniazid together, for a specific period. Rifapentine has been recently registered in India by Sanofi, and will be rolled out next year.

While India carries the highest burden with an estimated 2.7 million TB cases in 2018, more alarming is the possibility of a large pool of people harbouring the ‘silent infection.’ About 35-40% of the country’s population may have latent TB infection. Latent TB occurs when a person has the TB bacteria within their body, but it is present in very small numbers, and does not cause any symptoms. It is recommended that only certain “target” groups, within those with latent TB infections, should receive treatment.

Macleods FDC, which contains Rifapentine and Isoniazid, will lead to an over 65% reduction in pill burden (36 tablets vs 108 tablets) over current single drugs and 80% over IPT (36 tablets vs 180 tablets). With its introduction, patients’ pill burden will substantially reduce, while compliance will improve.

When contacted, Vijay Agarwal, business development director of Macleods, said: “In our pursuit to provide novel and patient-friendly treatment for tuberculosis, we will soon introduce first fixed-dose combination tablet of rifapentine and isoniazid. We will launch this product in high burden countries, including India (subject to regulatory approvals) by Q1, 2020 at an affordable price. We have asked the government for waiver of Phase 3 clinical trials.”

The regimen referred to as 3HP, consists of Rifapentine and Isoniazid, once a week for 12 weeks. Though the US recommended this treatment for latent TB infection in 2011, there is no company which has made the fixed dose combination till now, experts say.

“Both rifapentine and isoniazid are old TB drugs, and several companies are in the process of co-formulating them. We are waiting for generic competition for 3HP, so that governments with high TB burden like India can scale up latent TB treatment with this regimen,” said Leena Menghaney, head – India & South Asia, MSF Access Campaign, an international humanitarian agency.