Optimizing DR TB Outcomes—TRIAD study

1 April 2022

CAPRISA is one of nine clinical research sites, and lead co-ordinator for the TRIAD study, a multi-center, multi-country Prospective Pragmatic Cohort study to assess the effectiveness, feasibility, acceptability, and cost-effectiveness of implementing the Xpert MTB/XDR (Xpert XDR; Cepheid) assay for rapid triage-and-treatment with a shorter, all-oral drug-resistant tuberculosis (DR-TB) treatment regimen.

The proposed study, led by Prof Kogie Naidoo, Study PI and Head of HIV-TB Treatment Research at CAPRISA, aims to screen approximately 4800 GeneXpert MTB/RIF or Ultra MTB-positive participants (irrespective of rifampicin resistance status) from clinical research sites in South Africa, Nigeria and Ethiopia to enrol 880 rifampicin-resistant and 400 isoniazid mono-resistant participants over a period of 12-18 months.

The Xpert XDR assay, a rapid genotypic test, will be implemented as a reflex test to detect resistance to isoniazid, fluoroquinolones and second-line injectable agents to provide rapid genotypic susceptibility testing to detect DR-TB.  Participants that test positive for Mycobacterium tuberculosis (M.tb) with rifampicin resistance will be enrolled into Cohort 1 (n=880). Participants that test positive for M.tb that are rifampicin susceptible with isoniazid mono-resistance will be enrolled into Cohort 2 (n=400).

“This research will provide information about the feasibility, acceptability and cost-effectiveness of the DR TB triage-and-treat model, to inform policies and guidelines for programmatic implementation” said Prof Naidoo. The Xpert XDR assay will be used to guide selection of appropriate, evidence-based, all-oral DR-TB treatment regimen of shortest possible duration. The TB molecular bacterial load assay (TB-MBLA) will be used as an adjunct to provide bacillary load monitoring over the course of treatment to assess real-time DR TB treatment response. 

Prof Kogie Naidoo, Study PI and Head of HIV-TB Treatment Research at CAPRISA