With over 450 000 people contracting tuberculosis (TB) in South Africa annually, TB is the single biggest killer in the country. Unfortunately around three per cent of those infected are resistant to the two most effective drugs on the market, rifampicin and isoniazid. This form of tuberculosis is known as multidrug-resistant TB (MDR-TB).
Of these approximately 12 000 MDR-TB patients, 10 per cent are resistant to these two drugs, in addition to other drugs used to treat the condition. These patients are referred to as being extensively drug-resistant (XDR). MDR-TB and XDR-TB patients don’t respond to the standard six months of treatment with so-called “first line” TB drugs. Hence, they’re treated with drugs that are less potent, more toxic and a lot more expensive.
“While the proportion of patients with drug-resistant TB may seem small, these patients consume over 40 per cent of the national TB budget,” says Professor Grant Theron of the Centre of Excellence for Biomedical Tuberculosis Research at Stellenbosch University. “What’s more is they have dismal treatment outcomes – less than half and less than 1/4 people with MDR- or XDR-TB are ever cured. Treatment is also long – until recently up to 24 months – and involves severe side effects.”
How effective is delamanid?
Delamanid is the latest anti-TB drug treatment on the market, and could help to improve these rates. “The treatment generally results in high rates of cure, with around 35 per cent more patients being cured,” says Theron.
With delamanid, the TB bacteria is killed faster when it is included in TB drug regimens. “However, there is a lack of high-quality evidence from well-conducted clinical trials on its long-term benefits such as mortality,” cautions Theron.
Delamanid isn’t currently registered for use in South Africa, but has been approved by the European Union, Japan and South Korea.
When will delamanid be available?
“Delamanid has been available in South Africa on a select basis since the beginning of the year, so in some ways, the roll-out has already started,” says Theron. “However, the treatment has been restricted to a minority of patients who are treated at specialised facilities. The government may expand the delamanid access programme, but the exact timelines are unclear.”
What about bedaquiline?
In 2012 a similar access programme paved the way for the national rollout of the DR-TB drug bedaquiline, which was the first new TB drug to hit markets in almost 40 years.
“Bedaquiline is currently used to mostly treat patients with resistance beyond MDR-TB, or in patients with MDR-TB in whom other drugs are not an option, for example, due to side effects,” explains Theron. “Access to bedaquiline has traditionally been strictly controlled by the government, where patients that were likely not to benefit or were likely to develop resistance to bedaquiline were denied. This is controversial, however, and the government has been working to slowly expand access.”
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