A recent study conducted in Rio de Janeiro, Brazil, suggests that bedaquiline-containing regimens (BCR) are associated with favorable treatment outcomes and a lower risk of adverse events (AEs) in patients with rifampicin-resistant/multidrug-resistant tuberculosis (RR/MDR-TB). The findings, published in BMC Infectious Diseases, offer valuable insights into the real-world effectiveness of bedaquiline in managing this challenging disease.
The study, which followed a cohort of patients at a reference center, revealed that the implementation of BCR was associated with a nearly 10% increase in favorable treatment outcomes (61% vs. 52.8%) compared to previous regimens. This improvement underscores the potential of bedaquiline to enhance TB treatment success rates.
Treatment Outcomes and Social Factors
The overall favorable treatment outcome in the cohort was 55.9%, slightly lower than the 63% reported globally by the WHO in 2020. However, multivariate and survival analyses demonstrated a clear association between bedaquiline regimens and positive treatment outcomes.
The study also highlighted the significant impact of social determinants on treatment success. Factors such as education level, alcoholism, smoking, and illicit drug use were statistically associated with negative treatment outcomes and smear conversion. These findings align with previous research identifying these characteristics as risk factors for TB in general and adverse treatment outcomes specifically.
Adverse Events and Tolerability
Interestingly, the absence of adverse events was inversely associated with favorable outcomes. The researchers suggest this could be because only patients who adhered to and completed treatment were able to report AEs. The time to the first presentation of AEs was also longer in the BCR group compared to the injectable-containing regimen (ICR) group.
While concerns about QT interval prolongation have been raised in the past regarding bedaquiline, none of the patients in this study exhibited this effect. This finding is consistent with other studies conducted under routine conditions where cardiac monitoring may not be systematically reported.
Limitations and Future Directions
The study acknowledges several limitations, including its retrospective nature and the inability to definitively attribute outcomes or AEs specifically to bedaquiline due to the multi-drug nature of the regimens. Additionally, the lack of standardized AE reporting made it difficult to assess and grade them comprehensively. The study also lacked sufficient power to show statistically significant differences in time to smear or culture conversion between TB treatment regimens.
Despite these limitations, the study provides valuable real-world evidence supporting the use of bedaquiline-containing regimens in the treatment of RR/MDR-TB. Further research is needed to address the identified limitations and to explore strategies for optimizing treatment outcomes in diverse patient populations, considering both clinical and social factors.
