The World Health Organization (WHO) estimates that tuberculosis (TB) prevalence is decreasing at a rate of about 2 per cent per year worldwide and that timely diagnosis and treatment have helped save 53 million lives between 2000 and 2016. However, with nearly half a million people developing drug-resistant tuberculosis (DR-TB) each year, TB poses a serious public health challenge globally.
In India—the country with the highest number of TB deaths—an estimated 1,30,000 people develop multidrug-resistant tuberculosis (MDR-TB) annually.
Without effective treatment, the death rate for people with the most resistant forms of TB is abysmally high. Globally, less than half of all patients who start MDR-TB therapy are treated successfully. Treatment is long and difficult, stretching over two years; it involves taking nearly 15,000 pills, including daily injections for the first six months. The medicines have severe and debilitating side effects, including deafness, liver or kidney toxicity and psychosis, curing just one in two people, and are far more expensive than those used to treat drug-sensitive TB. Encouragingly, after almost half a century, the new antibiotics—bedaquiline and delamanid—together with re-purposed drugs, now offer fresh hope to those at high risk of treatment failure: people co-infected with HIV and DR-TB, extensively and pre-extensively drug-resistant (XDR/pre-XDR) TB patients, and children with DR-TB.
Bedaquiline and delamanid, which received marketing authorisation in 2012 and 2014, respectively, are the first new TB drugs developed in nearly 50 years. The ‘high unmet medical need’ for new treatment options for MDR-TB led to the addition of bedaquiline and delamanid adult formulations to the WHO Essential Medicines List (EML) for TB in 2015, while delamanid was added to the WHO EML for children in 2017.
Although the medications bring new hope to DR-TB patients, their use worldwide is still very limited.
Today, they represent a potential lifeline for people affected with the most resistant forms of TB, but the true value of these drugs will be seen in the coming years — when they can be used as substitutes for the drugs with nasty side effects (injectables, for example); when they can be combined more routinely for patients with limited treatment options; and when they can be used to reduce the treatment duration of MDR-TB. While we wait for evidence from real-life settings in 2019 and beyond, it is possible for India to make these drugs more affordable and available to TB programmes in developing countries by ensuring generic supply.
Already, on March 6, the WHO Prequalification Programme issued an expression of interest (EoI) to TB drug manufacturers for product evaluation of bedaquiline and delamanid. This is a good signal for manufacturers in India — in line with what happened earlier on HIV and hepatitis C drugs — as it is the first step towards validating sources of quality-assured generics.
However, generic manufacturers face significant patent barriers. Bedaquiline and delamanid, two of the first TB drugs to be patented following India’s adoption of the WTO product patent regime for pharmaceuticals in 2005, are set to expire half a decade later, in July and October 2023.
On the eve of the Delhi End TB Summit on March 13, clinicians, survivors of drug-resistant tuberculosis, health organisations and the TB community from across the world appealed to the Indian Prime Minister to issue a government use licence in order to encourage generic supply from Indian manufacturers.
The Patents Act provides for a special provision that empowers the central government to notify a ‘government use’ licence for ‘public non-commercial use’. Such a licence for bedaquiline and delamanid would encourage generic production and supply to India's TB Control Program while reserving them for public health use. Prices of these drugs could be reduced by up to 95 per cent through generic competition, reducing government spending, ensuring sustainable supply to the TB programme and help operationalise generic supply of these drugs to DR-TB treatment programmes in other high-burden countries.
The writer is with MSF - Médecins Sans Frontières or Doctors without Borders' Access Campaign. Views expressed are personal.