“The treatment of XDR-TB has been dire ever since this form of the disease was discovered,” says Jay Achar, Infectious Disease Specialist and TB Medical Advisor at Doctors Without Borders (MSF). “Having access to effective treatment regimens will give people hope of a cure and help programmes limit transmission of this deadly bacterium. While safer, simpler regimens are still needed, the shorter treatment duration of this novel regimen is an important step in the right direction.”

Clinical trials indicate that new XDR-TB drug pretomanid could be effective in up to 90% of cases, but does its price tag place it beyond reach of those who need it most?

As the third new drug developed for the treatment of TB in over half a century, and the first to be developed as part of a ready-to-use treatment regimen, pretomanid’s approval represents a possible milestone for the treatment of difficult-to-treat drug-resistant forms of TB.

The three-drug regimen (BPaL: bedaquiline + pretomanid + high-dose linezolid) was approved on Wednesday for adult patients with XDR, treatment-intolerant, or nonresponsive multidrug-resistant pulmonary TB. This new regimen could dramatically shorten treatment length to six months, greatly reduce the number of pills required, and help to increase XDR-TB cure rates from the terrible historical figure of 34%. While the new regimen will be shorter and simpler to administer, optimism around BPaL is balanced against the need for intensive monitoring for side effects from the high doses of linezolid required. Separate clinical trials run by MSF and TB Alliance are underway to further evaluate pretomanid-containing regimens to try to identify safer future treatment options.

In 2017, MSF launched the multi-site TB PRACTECAL clinical trial to evaluate the effectiveness of bedaquiline and pretomanid as part of a treatment regimen for multidrug-resistant TB (MDR-TB) and XDR-TB. Outcomes from this trial are expected by 2021. TB Alliance, a non-profit organisation, that owns pretomanid, has recently licensed it to US pharmaceutical corporation Mylan to register and supply the drug.