SA scientists helping to develop ‘game-changing’ TB drug

19 August 2014

South African scientists are part of an international research group that is on track to deliver more effective, less expensive and shorter TB treatment using a new combination of drugs.

The trial results of a three-drug combination called PaMZ, unveiled at the International Aids Conference in Melbourne last month, offer hope of the first new medication in half a century for the widespread treatment of tuberculosis – and one which also has the potential to cure multi-drug-resistant TB.

The trial was conducted by New York-based non-profit group the TB Alliance, in collaboration with scientists at South Africa’s University of Cape Town, Stellenbosch University and University of the Free State.

The study showed that PaMZ – described by TB Alliance director Mel Spigelman as a potential “game-changer” – killed TB bacteria twice as rapidly as standard TB treatment after just two months of therapy.

Dr Rod Dawson, consultant pulmonologist and head of the Clinical Research Unit at the UCT Lung Institute, said this could reduce the duration of standard TB treatment from the current six months to four.

“The breakthrough follows a two-month trial involving 200 TB patients from South Africa and Tanzania. Some received the standard treatment, others were given the new anti-TB drug PA-824 and moxifloxacin and pyrazinamide,” said Dawson, who is the international principal investigator on the study, which was also conducted at the UCT Lung Institute.

The study results showed that 70% of patients using the new drug had no TB in their sputum after two months. The commensurate figure for patients on the standard treatment was 50%.

It was the longest study of the new three-drug combination to date.

Importantly, the study also showed that the new drug is safe to take with antiretrovirals. South Africa carries a heavy co-burden, with 60% of TB patients infected with HIV.

The new drug is also promising in the fight against multi-drug-resistant TB. The World Health Organisation estimates that 150 000 cases have been diagnosed in South Africa alone. MDR-TB is resistant to both of the most commonly used anti-TB drugs, rifampicin and isoniazid.

It’s also potential good news for MDR-TB patients (10% of the study sample). Thirty percent MDR-TB patients respond to pyrazinamide and this is where the potential becomes most startling.

In these cases, the new drug combination could reduce MDR-TB treatment by about 18 months, and the number of pills by 97%, dramatically reducing costs, says the TB Alliance.

A longer follow-up study on the novel drug trio will start in 2015. It will be conducted in 10 countries, including South Africa, China and Zambia. Results are expected in 2018.

First published on the University of Cape Town’s Daily News page. Published here with kind permission.