Drug-resistant tuberculosis treatment

Unpublished data. After the GDG meeting, the TB Alliance shared with WHO an additional report 
(unpublished and confidential at the time of the release of the current guidelines) that included 
comparison of data from the Nix-TB study with a cohort of patients with XDR-TB, treated at one of 
the study sites. The comparison group in these analyses comprised 102 XDR-TB patients treated in 
a programmatic setting in South Africa, between November 2013 and April 2016. All patients in the 
comparison group had laboratory-confirmed XDR-TB, with TB isolates resistant to rifampicin, isoniazid, 
ofloxacin and amikacin. About half of the patients in the comparison group had HIV infection (51.0%). 
These comparative analyses were carried out by a data analyst under contract to the TB Alliance, 
who used a methodology that differed from that used for the analyses that informed the WHO 
recommendation on the use of BPaL presented in these guidelines, and no IPD were provided. Thus, 
the comparative analyses are not directly comparable to the analyses presented in Annex 3. Although 
this report could not be considered by the GDG during the November 2019 meeting (given that is was 
not made available until after the meeting), it was reviewed by the WHO Guideline Steering Group 
and the GDG before finalizing the guidelines document. The comparison in this report reinforces the 
positive treatment success rates that have been observed with the use of the BPaL regimen. In these 
analyses, the treatment success rate for patients receiving BPaL was 89.9% (98/109) versus 66.7% 
(56/84) for patients receiving another XDR-TB regimen that also contained bedaquiline and linezolid, 
yielding an adjusted risk ratio of 1.31 (95% Cl: 1.11–1.55, P=0.0012). The detailed data that supported 
this comparison, together with the results of operational research in other settings, may be useful for 
informing policy recommendations on the use of BPaL in the future.