First promising TB drug in decades, say researchers

Mycobacterium tuberculosis
Flickr/AJC1
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The first new tuberculosis drug in 40 years has successfully treated multidrug-resistant tuberculosis (MDR-TB) patients in a clinical trial in South Africa.
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Diarylquinoline TMC207 works differently from other anti-tuberculosis drugs by targeting an enzyme of Mycobacterium tuberculosis, the agent that causes TB.
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"This is an exciting new development and the first new TB drug in over forty years," says Alexander Pym, one of the researchers and a chief specialist scientist at the South African Medical Research Council's Clinical and Biomedical TB Research Unit based in Durban, South Africa.
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The researchers gave the drug to 20 patients in addition to standard therapy for MDR-TB for eight weeks.
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Twenty-one patients received a placebo plus standard treatment.
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About half the patients on TMC207 were successfully treated compared to about ten per cent on the placebo. The patients are being monitored to see if treatment remains effective.
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TMC207 was discovered using an old method of drug discovery that has not been used in the last 40 years.
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Modern approaches use computer software to identify drug targets and then design the desired drug, while this approach tests compounds on a rapidly growing relative of M. tuberculosis.
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"What we saw over the eight weeks was a significant difference in the rate in which tuberculosis disappeared," Andreas Diacon, one of the researchers, and the director of the Centre of Clinical Tuberculosis Research at the University of Stellenbosch, told SciDev.Net.
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The drug works on both drug-susceptible and drug-resistant TB in the laboratory and the implications are that this new drug might shorten treatment time for all tuberculosis patients, says Diacon.
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MDR-TB patients take five drugs for up to 18 months and patients with standard tuberculosis take four drugs for six months.
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Diacon adds that because this is a new drug with a new way of working patients will not have developed a resistance — potentially increasing the proportion of people who could be cured.
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A second group of MDR-TB patients is now undergoing a longer, six-month trial of TCM207 in South Africa.
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The research was published in the New England Journal of Medicine this month (4 June).
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Sharon Davis
CAPE TOWN
SciDev
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full abstract

http://content.nejm.org/cgi/content/full/360/23/2397