Drug resistant TB: ‘groundbreaking’ drug approved by US regulators

A new drug regimen which cures almost 90 per cent of patients with the most difficult to treat strains of tuberculosis has been approved by regulators in America.

The drug, pretomanid, has been developed to treat both extensively drug-resistant tuberculosis (XDR-TB) and multi-drug resistant TB (MDR-TB) when used in conjunction with two other tablets.

It is only the third new anti-TB drug approved for use by the US Food and Drink Administration (FDA) in 40 years.

Although deaths from TB have fallen since the millennium, it remains one of the deadliest diseases in the world, killing roughly 1.6 million people and infecting 10 million every year.

But experts are increasingly alarmed at how quickly almost untreatable XDR and MDR strains of TB are spreading across the globe, with drug resistance identified on every continent.

Recent reports have suggested that the spiralling number of deaths as resistance spreads could cost the world economy nearly $20 billion annually.

“We are seeing an increase in XDR-TB, and we need new weapons to attack it,” said Dr Doris Rouse, vice president of global health technologies at RTI International, a nonprofit research and development institute based in the US.

“I’ve been in wards with patients that are so emaciated, they won't eat anything, they have fevers, they can’t sleep. But with pretomanid, in a regimen that includes two other drugs, bedaquiline and linezolid, we see improvement within a few weeks.

“This new treatment will help people who have no other good option for a cure,” she added.

The new drug is used in combination with two others in a six-month, tablet-based treatment regime known as BPaL: bedaquiline, pretomanid and linezolid.

In trials in South Africa, the BPaL treatment cured some 89 per cent of patients. Previous treatment options for XDR and MDR-TB involved a two year regimen which cured between two and 22 per cent of patients.

“I would say the [new drug regimen] would qualify as groundbreaking,” said Dr Daniel Everitt, senior medical officer at the TB Alliance.

“We are going from an 18 to 24 month treatment regimen – where patients take between six and eight different drugs and with limited chance of success – to a six month regimen with three drugs which cures nine in ten patients,” he said. “This really is a dramatic step forward and will have major public health benefits.”

Dr Everitt added that the new treatment would be earmarked for use only for XDR and MDR-TB cases, to reduce the chance of the disease developing resistance against pretomanid.

The TB Alliance will now work towards introducing the BPaL treatment regime in countries with the highest burden of drug resistant strains.

The FDA’s decision is crucial in accelerating progress, as countries across the globe tend to follow the advice of American and European regulators and the World Health Organization.

The TB Alliance is part-funded by UK aid and the International Development Secretary, Alok Sharma, said he was “proud that our long-term support has contributed to the development of this groundbreaking treatment”.

“The UK is already leading the way to tackle TB through investment in research and development, and our scientists continue to develop new TB drugs to treat the millions of people still suffering with the disease,” Mr Sharma said.

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