Extensively drug-resistant TB outcomes remain poor in Europe

TOPLINE:

Only four out of 10 patients with extensively drug-resistant tuberculosis (TB) in Europe achieved successful treatment outcomes, a rate markedly lower than that for other forms of drug-resistant TB and comparable with cure rates from the pre-antibiotic era.

METHODOLOGY:

• Researchers conducted a retrospective observational cohort study across 16 countries of the World Health Organization (WHO) European Region to evaluate treatment outcomes in 188 patients (median age, 42 years; 79.3% men) with extensively drug-resistant TB.
• Data collected included patient characteristics, disease localisation, prior treatments, phenotypic and genotypic drug susceptibility testing results, and treatment regimens.
• Treatment outcomes were categorised as successful, failure (microbiological or clinical reasons including regimen changes), lost to follow-up (treatment interrupted for 2 or more months), or not evaluated.

TAKEAWAY:

• Among the 188 patients with extensively drug-resistant TB, 48.4%, 34.0%, and 17.6% of Mycobacterium tuberculosis strains were resistant to bedaquiline alone, linezolid alone, and both drugs, respectively.
• Among 156 patients with available data for treatment outcomes, 40.2% (95% CI, 28.4%-53.2%) achieved successful outcomes in a pooled analysis accounting for between-country heterogeneity.
• Patients with extensively drug-resistant TB had lower pooled success rates (P < .0001) and significantly higher pooled rates of treatment failure and death (P < .0001 and P = .008, respectively) than those with multidrug-/rifampicin-resistant or preextensively drug-resistant TB.
• The likelihood of an unsuccessful outcome decreased with each additional effective drug in the regimen (P = .026) but increased among patients treated in upper-middle-income countries compared with that among those treated in high-income countries (P < .001).

IN PRACTICE:

“[The study] findings underscore the need for improved, rapid DST [drug susceptibility testing] tools and effective, shorter treatment regimens for extensively drug-resistant tuberculosis,” the authors wrote.

SOURCE:

This study was led by Yousra Kherabi, Bichat-Claude Bernard Hospital, Assistance Publique-Hôpitaux de Paris, Université Paris Cité, Paris, France, and Ole Skouvig Pedersen, Aarhus University Hospital, Aarhus, Denmark. It was published online on July 15, 2025, in The Lancet Regional Health – Europe.

LIMITATIONS:

The coverage of the WHO European Region was limited. Most of the participating centres were specialist or referral centres, which may have introduced selection bias and limiting generalisability. Although the use of WHO-defined outcomes simplified data collection, it constrained a detailed understanding of treatment failures. Moreover, individual-level data were available only for patients with extensively drug-resistant TB, which may have introduced confounding from unmeasured patient-level factors.

DISCLOSURES:

This study did not receive any funding. One author reported serving as a co-principal investigator of clinical trials testing new regimens for multidrug-resistant TB, and some authors reported receiving honoraria for speaking engagements or serving on advisory boards of various pharmaceutical companies.

By Devyani Gholap

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