Hyderabad: Delegates from around the world met here on Tuesday, October 29, for a week of discussions on the science and policy surrounding tuberculosis or TB.
TB is one of the world’s deadliest infectious diseases, estimated to have killed 1.5 million people in 2018 alone. India has the world’s highest burden of TB.
While cures and treatment of TB has a big role to play, the next few days at the TB Science 2019 conference is likely to see focused discussion and a slew of new announcements around the prevention of the disease.
The conference is being hosted by The Union, as part of its 50th World Conference on Lung Health.
Both the major announcements that were made on Tuesday had to, therefore, do with its prevention.
First was the announcement that pharmaceutical company Glaxo SmithKline (GSK) had successfully conducted phase 2b trial of their TB vaccine M72/AS01, data from which was published in the New England Journal of Medicine.
The company said that their trials showed a high rate of efficacy, consistent with what the World Health Organisation has said is the desirable rate.
Secondly, the US’s National Institutes of Health announced that it will spend $30 million to fund the country’s three top institutes for studies on TB immunology and vaccine development.
How good is the new vaccine?
Speaking on the vaccine, WHO representative, Nebiat Gebreselassi said, “The WHO is very excited about the results from the M72 phase 2b trial vaccine.”
The WHO has organised a high-level meeting to discuss the results of the trial and discuss with funding partners, developers and other countries about what steps to take next.
“WHO will continue to support the development of the M72 vaccine and once the results are confirmed of this very exciting vaccine, we will support member states to adopt and implement it,” said Gebreselassi.
The results of the study have it that the M72 vaccine “provided 54% protection against active pulmonary tuberculosis disease, without evident safety concerns.”
So far, the study can say that this protection works for three years. The study reports the results of their three-year-long study on the grounds of efficacy, safety and immunogenicity.
In the trial, the vaccine was tested on 3,575 people who already had latent TB and who were also HIV negative. It was tested in 11 sites, in Kenya, South Africa and Zambia.
Among the various groups in the trial, 13 participants who had taken the GSK vaccine did develop active pulmonary TB but this number was significantly fewer than the 26 people who developed TB in the placebo group which was not given the vaccine.
It is on this basis that the trial has concluded that it has about 50% efficacy in comparison to the placebo.
However, caution is needed while considering the numbers. “A 50% efficacy vaccine may finally be only 25% effective in field situations. Undernutrition has a direct link to TB. Why won’t people talk about food as a “vaccine” to prevent disease? It is in fact heat stable, oral, locally produced and cheap, and more than 50% effective in preventing TB and has additional spin offs when people have good nutrition,” says Yogesh Jain, a doctor from Jan Swasthya Sahyog in Chhattisgarh.
“At 3,000 odd participants, its still a relatively small trial. Thirty-nine people still got TB. It was 13 in one arm versus 26 in another arm, who got TB. But if there were one or two cases of TB more in the vaccine group, then the percentage of efficacy could have been much lower. That’s why we need to do more and bigger trials before regulators are actually comfortable to get it out,” said Ann Ginsberg, senior technical adviser at the International AIDS Vaccine Initiative. IAVI has partnered with GSK on this vaccine.
But the global health community has still welcomed this update on the vaccine, largely because it meets WHO’s theoretical standard of 50% protection. No TB vaccine has so far managed this standard.
“This is the first time a vaccine has shown this kind of protection in 100 years and has managed to show it in an efficacy trial. There are other TB vaccines under development but most of them are still at very nascent stages, and have reported data on safety and immunogenicity. They have not reported data on efficacy of the vaccine,” said Ginsberg.
TB in the news this week
Apart from Tuesday’s updates, this week will see a number of other major announcements on TB at the global conference in Hyderabad.
On Wednesday, Vice-President Venkaiah Naidu will officially inaugurate the 50th Union World Conference on Lung Health.
On Monday, the TB Alliance announced that Indian company Macleods is going to be the second generic company to be allowed to manufacture the drug Pretomanid which is used to treat highly drug-resistant TB, as part of a regimen along with Bedaquiline and Linezolid.
Pretomanid is also only the third new anti-TB drug to be approved by the USFDA in 40 years (the other two are Bedaquiline and Delamanid), indicative of just how few options are in the pipeline for TB prevention or cure.
Pretomanid also got a boost from the Global Drug Facility which announced on Tuesday that it is now listing its first ever, all-oral regimen which includes this drug at $ 1,040 per treatment course.
The global humanitarian organisation, Doctors Without Borders (Médecins Sans Frontières or MSF) has responded to this, calling this price too high. This is because Pretomanid has to be taken in conjunction with Bedaquiline, which is also an expensive drug.
MSF has also been campaigning for Janssen to bring down the price of Bedaquiline. They want the price of the entire drug resistant TB course to be no higher than $ 500 per person. Right now, TB Alliance is offering the course for $ 1,040. Researchers at the University of Liverpool however, had estimated that generic versions of Pretomanid could be sold (for a profit) for as little as $ 35 a month.
“The public helped pay for the development of this drug, and therefore this drug should be affordable and accessible to anyone who needs it,” says Sharonann Lynch, HIV and TB policy advisor of the MSF Access Campaign.
The Medicines Patent Pool has also announced that it has signed a license with pharma giant Pfizer, for access to data on the investigational TB treatment with Sutezolid. Sutezolid is a potential drug that can also be given in combination with other drugs, to treat multi drug resistant TB. So far this drug has only reached phase 2a in clinical trials and there has been no development on it since 2013.
Pfizer has granted the Medicines Patent Pool a non-exclusive, worldwide and royalty-free licence which can allow the pool to sub-license the drug candidate and its phase 1 clinical trial data to others. So far, Johns Hopkins University is already on board to take the research further.
Lancet has also given TB prime space in its journal with an editorial that says that the world is “not on track to achieve the Sustainable Development Goal target of reducing mortality from tuberculosis by 90% by 2030.”
The Lancet Commission on TB is currently chaired by India’s Soumya Swaminathan who is the WHO’s chief scientist.
Anoo Bhuyan is in Hyderabad reporting as one of ‘The Union’s Media Scholars’ at the ‘50th Union World Conference on Lung Health’.