TB is caused by infection with Mycobacterium tuberculosis
Tuberculosis which is resistant to many current treatments can be overcome with aggressive therapy, research suggests.
Extensively drug-resistant TB is associated with high rates of mortality and is thought to account for at least 7% of cases of the infection worldwide.
Despite fears that it is untreatable, researchers have shown a cure is possible with a combination of at least five drugs, The Lancet reported.
UK experts said it was good news but would require a lot of resources.
Multi-drug resistant (MDR) TB, of which there are around 50 to 70 cases every year in the UK, is resistant to the most commonly used treatments isoniazid and rifampin.
But in extensively resistant (XDR) TB, at least two of the second-line treatments are also worthless.
Some experts have speculated that XDR-TB is effectively untreatable and there were grave concerns after reports of 52 deaths in 16 days in South Africa after an outbreak among patients with HIV.
In the latest trial done in 600 patients in Russia with resistant TB, researchers found that almost 5% of them had XDR-TB.
Each patient was given an individually tailored treatment programme on the basis of the strain they had.
The aim was to provide at least five drugs to which that particular patient's strain of TB was susceptible.
Almost half of XDR-TB patients and 67% of MDR-TB patients had treatment cure on completion.
Study leader Dr Salmaan Keshavjee, from Harvard Medical School in the US, said: "Aggressive management of this infectious disease is feasible and can prevent high mortality rates and further transmission of drug-resistant strains of TB."
Dr John Moore-Gillon, a spokesperson for the British Lung Foundation, said the bad news is that we have XRD-TB in the first place.
"The reason we have the problem is inadequate control of TB.
"This treatment is extremely labour and resource intensive and has to be done within extremely well structured TB programmes.
"It's a very important paper showing it's possible to deal with XDR-TB but it's very expensive."
He added that MDR-TB treatment costs tens of thousands but for XDR-TB it's "much more than that".