HMN 2026: How Long-term cure rates for multidrug-resistant tuberculosis is much better than expected

A new national cohort study provides important insights into the treatment of multidrug-resistant tuberculosis (MDR-TB). The study shows that long-term disease-free survival rates are significantly higher than previous standard indicators suggest. The results, published in The Lancet Regional Health Europe, are based on the analysis of data from 1,299 adult patients treated between 2005 and 2021. The study was in collaboration with researchers from the clinical tuberculosis infrastructure (ClinTB) at the German Center for Infection Research (DZIF) at the Research Center Borstel, Leibniz Lung Center (FZB).

Multidrug-resistant tuberculosis poses a significant challenge to health care systems worldwide. While the effectiveness of treatment is traditionally assessed on the basis of treatment outcomes at the end of therapy, the new study shows that these criteria underestimate the actual long-term success of treatment. According to WHO standard definitions, only 4.8% of patients in Latvia were considered cured. However, during long-term follow-up, 76.9% of those affected remained permanently relapse-free.

The researchers linked clinical data with national registry information for long-term follow-up, enabling them, for the first time, to systematically evaluate long-term treatment outcomes in a former European country with a high incidence of MDR-TB. A key factor in treatment success was the use of at least three effective drugs in the individual treatment regimen.

Furthermore, the analysis showed that very short treatment durations of less than nine months, using the treatment options available at the time, were associated with an increased risk of relapse or death. Treatment durations of between ten and seventeen months, however, achieved comparable results to longer courses of treatment. After the end of the observation period, MDR-TB treatments became more effective. Today, the treatment duration for MDR-TB has aligned with the six months required for drug-sensitive tuberculosis.

“The study underscores the importance of long-term follow-up in MDR-TB and suggests that tuberculosis control programs should broaden their measures of success. Including recurrence-free survival rates allows for a more realistic assessment of the quality of care and the actual benefit to patients,” says Sophie Meier, a medical Ph.D. student at the FZB and the University of Lübeck under DZIF researcher Professor Christoph Lange.

“The findings also support the role of expert panels, known as consilia, in selecting treatments and assessing treatment success for MDR-TB. In Latvia, the decisions made by the consilium were significantly superior to the results obtained by applying WHO definitions for MDR-TB treatment outcomes. Consilia are also an element of effective ‘antimicrobial stewardship’ against the development of new antibiotic resistance,” says PD Dr. Thomas Brehm from the FZB and University Medical Center Hamburg-Eppendorf (UKE), DZIF researcher and senior author of this study.

The findings of this study provide important impetus for future treatment strategies for MDR-TB and support the use of individualized treatment regimens with sufficiently effective drugs. Prospective studies are now required to test these findings in the context of new, shortened treatment regimens using modern active substances. If necessary, the definitions of treatment outcomes for MDR-TB will need to be revised.

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