MANILA — Several new technologies are in the pipeline to diagnose and treat tuberculosis, including a promising vaccine that could prevent people with latent TB infection from developing the disease, according to the World Health Organization’s latest report.
The vaccine, M72/AS01E, showed a 54% vaccine efficacy among HIV-negative adults infected with TB in Kenya, South Africa, and Zambia who were followed for over 2 years in a Phase IIb efficacy trial — which is meant to test the efficacy and safety of a drug. The result, which the report described as “unprecedented in decades of TB vaccine research in terms of the clinical significance and strength of evidence,” could transform global TB prevention efforts. An estimated 1.7 billion people are infected with TB and at risk of developing the disease, according to the “Global Tuberculosis Report 2019.”
However, several questions persist and will need to be further tested, such as its ability to protect everyone — including those with no TB infection, people living with HIV, and populations in other geographic areas.
The vaccine is one of the 23 drugs, combination regimens and vaccine candidates currently in clinical trials highlighted by WHO in the report. Developing a vaccine to lower the risk of TB infection, a vaccine or new drug to cut the risk of TB disease among those with latent TB, rapid diagnostics to be used at point of care, and simpler and shorter TB drug treatment regimens are a key R&D priority.
The list of diagnostics and tools to prevent and treat TB today is a far cry from a decade ago, when the pipeline was “almost empty,” Lucica Ditiu, executive director of the Stop TB Partnership based in Geneva, told Devex.
But this will require a similarly robust pipeline of funding, she said. The development of the vaccine to protect individuals from developing an active TB disease, for instance, may require half a billion dollars in investments, she added.
Funding for TB research and development in 2017 reached $772 million, but well below the target $2 billion annually that member states agreed to at the U.N. high-level meeting on TB in 2018.
Funding for TB prevention, diagnosis, and treatment activities in low and middle-income countries in 2018 was also short of over $3 billion. Available funding was only $6.8 billion, with a large bulk of it, 87%, coming from domestic financing.
External donor financing accounted for 38% of the funding available in 25 high TB burden countries, excluding countries comprising Brazil, Russia, India, China, and South Africa or the BRICS, according to the report.
Some of these TB high-burden countries however still suffer gaps in funding even with domestic and international donor support combined, according to the report. In Liberia, 77% of the required TB funding is not available, followed by 75% in North Korea and 72% in Tanzania. In the Democratic Republic of Congo, where there’s an ongoing Ebola outbreak, the funding gap is 41%.
Experts welcomed The Global Fund to Fight AIDS, Tuberculosis and Malaria’s successful replenishment last week, in which the multilateral raised a little over its target of $14 billion for the next three years. The Global Fund accounted for 73% of external financing for TB worldwide in 2019, according to the report.
But experts have mixed feelings over the replenishment. Ditiu said the replenishment was welcome, but only 18% of the raised money will go to TB in the disease split allocation between AIDS, TB and malaria , or about $800 million a year for TB for all Global Fund-eligible countries, she said.
“So what we’ll try to do is reopen the disease split discussion, but for the next replenishment,” Ditiu said. The disease split for the upcoming funding cycle has already been decided, she said.
“It’s very difficult to say life of a TB person is more important than the one with malaria and HIV,” she said. “It will not be an easy discussion.”
Sharonann Lynch, HIV and TB policy advisor for Médecins Sans Frontières’ Access Campaign, also described the replenishment as good news, but said that there are still a lot of unmet needs.
“The report recognizes … an increase in domestic resources, but as the report that MSF put out ... we have to be smart in how we look at these numbers, look at the trends in funding and how donors are pushing for more [of] what they refer to euphemistically as country ownership, when really it's breaking an agreement towards shared responsibilities in terms of fighting pandemics,” she said.
“There needs to be more collective efforts from both national governments and donor governments rather than shifting the burden,” she added.
Lynch also highlighted issues of pricing and patent, and how these are posing barriers for countries and people to benefit from the technological innovations happening in the TB space.
“The treatment for drug sensitive TB is cheap, largely because treatment has remained unchanged for so many years. So we haven't had new drug sensitive TB treatment for many years. Where we have had some differences is for drug resistant TB … the prices are so bloody high, that's still we're seeing such slow scale up,” she said.
One example she gave is the drug delamanid, whose lowest price for countries purchasing through the Global Drug Facility is at $1,700. When used in combination with other treatments, as is the case when treating drug-resistant TB, she said cost can run as high as $11,000 for one person in one treatment course.
“I think we're not gonna see the changes that we need to see in the scale up of testing and treatment for drug resistant TB, and of course the most important thing cure rates, unless we see more affordable tools that are more widely available,” she said.
According to the report there were 186,772 cases of MDR-TB or rifampicin-resistant TB notifications in 2018, up from 160,684 in 2017. While there’s been an increase in the number of cases enrolled for treatment — 156,071 from 139,114 in 2017 — there are still fewer people receiving treatment. In 2018, that’s just 32% of the estimated case incidence of 484,000.