Availability and costs of medicines for the treatment of tuberculosis in Europe

Randomized Controlled Trial of Clinical Guidelines Versus Interactive Decision-Support for Improving Medical Trainees' Confidence with Latent Tuberculosis Care

BACKGROUND

In order to eliminate tuberculosis (TB) in the USA, primary care providers must take on an expanded role in the diagnosis and management of latent tuberculosis infection (LTBI). Clinical practice guidelines and recommendations exist for LTBI management, but there is a need for innovative tools to improve medical students' and residents' knowledge of evidence-based practices for LTBI testing and treatment.

OBJECTIVE

To assess the impact of LTBI-ASSIST, a free online decision support aid, as a novel educational tool and mechanism of delivering clinical practice guidelines for medical trainees.

DESIGN

A single site, randomized controlled trial of trainees delivered by electronic survey.

INTERVENTIONS

Medical students and Internal Medicine residents at the Johns Hopkins University School of Medicine.

PARTICIPANTS

Participants were randomized in 1:1 ratio to receive the US clinical practice guidelines and recommendations for Latent TB management (control arm) or the guidelines plus an introduction to LTBI-ASSIST (LTBI-ASSIST arm) as they completed a case-based knowledge assessment and reported confidence with domains of LTBI care.

MAIN MEASURES

(1) Proportion of questions answered correctly on a case-based knowledge assessment; (2) change in reported confidence with domains of LTBI care.

KEY RESULTS

One hundred and thirty participants completed the knowledge assessment. Those randomized to receive the LTBI-ASSIST Tool performed better on the case-based knowledge assessment with a mean score of 75.9% (95% CI: 70.6-81.1), compared to 57.4% (52.8-62.0) in the group that received the guidelines only (p <0.001). Similarly, the LTBI-ASSIST group reported a higher change in confidence (measured as post-assessment confidence minus pre-assessment confidence), compared to the control group, in six of the seven domains of LTBI care.

CONCLUSIONS

LTBI-ASSIST can be an effective supplement to existing guidelines in educating medical trainees and helping providers find evidence-based, guideline-supported answers for questions encountered in clinical practice.

TRIAL REGISTRATION

NIH Clinical Trial Registry No. NCT05772065.

Availability of drugs for the treatment of multidrug-resistant/rifampicin-resistant tuberculosis in the World Health Organization European Region, October 2023

The BPaLM regimen (bedaquiline, pretomanid, linezolid and moxifloxacin) recently recommended by the World Health Organization offers short, safe, and effective treatment for multidrug-resistant/rifampicin-resistant tuberculosis (TB). In a survey with national TB focal points in 18 central and western European countries to explore barriers for the implementation of BPaLM, only three reported full availability of pretomanid, a necessary component of this regimen. Implementation barriers included financing and procurement. Solutions on national and supranational level are needed to guarantee universal access.

Multidrug-resistant tuberculosis

Tuberculosis (TB) remains the foremost cause of death by an infectious disease globally. Multidrug-resistant or rifampicin-resistant TB (MDR/RR-TB; resistance to rifampicin and isoniazid, or rifampicin alone) is a burgeoning public health challenge in several parts of the world, and especially Eastern Europe, Russia, Asia and sub-Saharan Africa. Pre-extensively drug-resistant TB (pre-XDR-TB) refers to MDR/RR-TB that is also resistant to a fluoroquinolone, and extensively drug-resistant TB (XDR-TB) isolates are additionally resistant to other key drugs such as bedaquiline and/or linezolid. Collectively, these subgroups are referred to as drug-resistant TB (DR-TB). All forms of DR-TB can be as transmissible as rifampicin-susceptible TB; however, it is more difficult to diagnose, is associated with higher mortality and morbidity, and higher rates of post-TB lung damage. The various forms of DR-TB often consume >50% of national TB budgets despite comprising <5-10% of the total TB case-load. The past decade has seen a dramatic change in the DR-TB treatment landscape with the introduction of new diagnostics and therapeutic agents. However, there is limited guidance on understanding and managing various aspects of this complex entity, including the pathogenesis, transmission, diagnosis, management and prevention of MDR-TB and XDR-TB, especially at the primary care physician level.

Availability of drugs and resistance testing for bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaL(M)) regimen for rifampicin-resistant tuberculosis in Europe

OBJECTIVES

Multidrug-resistant/rifampicin-resistant tuberculosis is a major obstacle to successful tuberculosis control. The recommendation by the WHO to use bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaL(M)) for 6 months, based on results of two trials with high efficacy and low toxicity, has revolutionized treatment options.

METHODS

In this study, representatives of the Tuberculosis Network European Trials group in 44 of 54 countries of the WHO Europe region documented the availability of the medicines and drug susceptibility testing (DST) of the BPaL(M) regimen through a structured questionnaire between September and November 2023.

RESULTS

In total, 24 of 44 (54.5%), 42 of 44 (95.5%), 43 of 44 (97.7%), and 43 of 44 (97.7%) countries had access to pretomanid, bedaquiline, linezolid, and moxifloxacin, respectively. Overall, 23 of 44 (52.3%) countries had access to all the drugs composing the BPaL(M) regimen. In total, 21 of 44 (47.7%), 37 of 44 (84.1%), 40 of 44 (90.9%), and 41 of 44 (93.2%) countries had access to DST for pretomanid, bedaquiline, linezolid, and moxifloxacin, respectively. Overall, DST was available for all medicines composing the BPaL(M) regimen in 21 of 44 (47.7%) countries, including countries where pretomanid DST was available at specialized laboratories. The availability of DST for the drugs the countries had access to, varied from 87.5% to 95.3% (pretomanid 21 of 24 (87.5%), bedaquiline 37 of 42 (88.1%), linezolid 40 of 43 (93.1%) and moxifloxacin 41 of 43 (95.3%)).

DISCUSSION

In only about half of the countries participating in the survey, clinicians had access to all the BPaL(M) regimen drugs. A complete DST for the BPaL(M) medicines was possible in less than half of the countries, because of the low accessibility of DST for pretomanid. Equal access to new regimens is urgently needed in Europe and a rapid scale up of DST, especially for pretomanid, is important to prevent unnoticed spread of drug resistance.

The efficacy and safety of high-dose isoniazid-containing therapy for multidrug-resistant tuberculosis: a systematic review and meta-analysis

Objectives: Accumulating evidence are available on the efficacy of high-dose isoniazid (INH) for multidrug-resistant tuberculosis (MDR-TB) treatment. We aimed to perform a systematic review and meta-analysis to compare clinical efficacy and safety outcomes of high-dose INH- containing therapy against other regimes. Methods: We searched the following databases PubMed, Embase, Scopus, Web of Science, CINAHL, the Cochrane Library, and ClinicalTrials.gov. We considered and included any studies comparing treatment success, treatment unsuccess, or adverse events in patients with MDR-TB treated with high-dose INH (>300 mg/day or >5 mg/kg/day). Results: Of a total of 3,749 citations screened, 19 studies were included, accounting for 5,103 subjects, the risk of bias was low in all studies. The pooled treatment success, death, and adverse events of high-dose INH-containing therapy was 76.5% (95% CI: 70.9%-81.8%; I2: 92.03%), 7.1% (95% CI: 5.3%-9.1%; I2: 73.75%), and 61.1% (95% CI: 43.0%-77.8%; I2: 98.23%), respectively. The high-dose INH administration is associated with significantly higher treatment success (RR: 1.13, 95% CI: 1.04-1.22; p < 0.01) and a lower risk of death (RR: 0.45, 95% CI: 0.32-0.63; p < 0.01). However, in terms of other outcomes (such as adverse events, and culture conversion rate), no difference was observed between high-dose INH and other treatment options (all p > 0.05). In addition, no publication bias was observed. Conclusion: In MDR-TB patients, high-dose INH administration is associated with a favorable outcome and acceptable adverse-event profile. Systematic review registration: identifier CRD42023438080.

How We Treat Drug-Susceptible Pulmonary Tuberculosis: A Practical Guide for Clinicians

Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide and pulmonary TB (PTB) is the main variant responsible for fueling transmission of the infection. Effective treatment of drug-susceptible (DS) TB is crucial to avoid the emergence of Mycobacterium tuberculosis-resistant strains. In this narrative review, through a fictional suggestive case of DS PTB, we guide the reader in a step-by-step commentary to provide an updated review of current evidence in the management of TB, from diagnosis to post-treatment follow-up. World Health Organization and Centre for Diseases Control (CDC) guidelines for TB, as well as the updated literature, were used to support this manuscript.

Investigation of genomic mutations and their association with phenotypic resistance to new and repurposed drugs in Mycobacterium tuberculosis complex clinical isolates

BACKGROUND

WGS has the potential to detect resistance-associated mutations and guide treatment of MDR TB. However, the knowledge base to confidently interpret mutations associated with the new and repurposed drugs is sparse, and phenotypic drug susceptibility testing is required to detect resistance.

METHODS

We screened 900 Mycobacterium tuberculosis complex genomes from Ireland, a low TB incidence country, for mutations in 13 candidate genes and assessed their association with phenotypic resistance to bedaquiline, clofazimine, linezolid, delamanid and pretomanid.

RESULTS

We identified a large diversity of mutations in the candidate genes of 195 clinical isolates, with very few isolates associated with phenotypic resistance to bedaquiline (n = 4), delamanid (n = 4) and pretomanid (n = 2). We identified bedaquiline resistance among two drug-susceptible TB isolates that harboured mutations in Rv0678. Bedaquiline resistance was also identified in two MDR-TB isolates harbouring Met146Thr in Rv0678, which dated back to 2007, prior to the introduction of bedaquiline. High-level delamanid resistance was observed in two isolates with deletions in ddn, which were also resistant to pretomanid. Delamanid resistance was detected in two further isolates that harboured mutations in fbiA, but did not show cross-resistance to pretomanid. All isolates were susceptible to linezolid and clofazimine, and no mutations found were associated with resistance.

CONCLUSIONS

More studies that correlate genotypic and phenotypic drug susceptibility data are needed to increase the knowledge base of mutations associated with resistance, in particular for pretomanid. Overall, this study contributes to the development of future mutation catalogues for M. tuberculosis complex isolates.

[Management of drug-resistant tuberculosis]

The spread of multidrug-resistant Mycobacterium tuberculosis bacteria jeopardizes tuberculosis control, especially in the WHO Europe region. Following the availability of novel drugs and treatment regimens the World Health Organization has updated management recommendations for patients affected by drug-resistant tuberculosis. These novel recommendations include a significant reduction in the duration of therapy. This review presents the epidemiology and diagnostics of antibiotic-resistant tuberculosis as well as up-to-date treatment recommendations.

Global treatment outcomes of extensively drug-resistant tuberculosis in adults: A systematic review and meta-analysis

INTRODUCTION

Historically, extensively drug-resistant tuberculosis has been notoriously difficult to treat with devasting outcomes. As we are coming to the end of an era where the 2006 extensively drug-resistant tuberculosis definitions and old treatment regimens are being replaced, we aimed to estimate the proportion of extensively drug-resistant tuberculosis patients globally who achieved successful treatment outcomes.

METHODS

We conducted a systematic review of PubMed/MEDLINE, Scopus, Web of Science, and Embase from January 1, 2005, through April 3, 2023. Included studies reported WHO treatment outcomes, or adaptions hereof, for pre-extensively and/or extensively drug-resistant tuberculosis patients according to the 2006 WHO definition. Eligible studies included cohorts of at least 10 adults (aged>18 years) that were not pregnant. Using a random-effects model, we calculated pooled proportions of treatment outcomes and performed sensitivity and subgroup analyses. PROSPERO registration number: CRD42022340961.

RESULTS

Among 5056 studies reviewed, we identified 94 studies from 26 countries, involving 10,223 extensively drug-resistant tuberculosis patients. The pooled proportion of successful treatment outcomes was 44.2% (95%CI: 38.3-50.3). Sensitivity analyses consistently produced similar estimates. A slight improvement in treatment outcomes was observed after 2013. Furthermore, 25 studies reported outcomes for 3564 individuals with pre-extensively drug-resistant tuberculosis, of which 63.3% achieved successful treatment (95%CI: 43.1-72.5).

CONCLUSION

Globally, the success rate of extensively drug-resistant tuberculosis treatment is 44.2%, far below the WHO's target rate of 75%. These results may serve as a reference for future studies assessing extensively drug-resistant tuberculosis treatment outcomes under the 2021 definition treated with better treatment regimens available. Comprehensive surveillance data of extensively drug-resistant tuberculosis outcomes from the whole world are desirable to monitor treatment progress.

Recent advances in the treatment of tuberculosis

BACKGROUND

Tuberculosis (TB) is a global health challenge and one of the leading causes of death worldwide. In the last decade, the TB treatment landscape has dramatically changed. After long years of stagnation, new compounds entered the market (bedaquiline, delamanid, and pretomanid) and phase III clinical trials have shown promising results towards shortening duration of treatment for both drug-susceptible (Study 31/A5349, TRUNCATE-TB, and SHINE) and drug-resistant TB (STREAM, NiX-TB, ZeNix, and TB-PRACTECAL). Dose optimization of rifamycins and repurposed drugs has also brought hopes of further development of safe and effective regimens. Consequently, international and WHO clinical guidelines have been updated multiple times in the last years to keep pace with these advances.

OBJECTIVES

This narrative review aims to summarize the state-of-the-art on treatment of drug-susceptible and drug-resistant TB, as well as recent trial results and an overview of ongoing clinical trials.

SOURCES

A non-systematic literature review was conducted in PubMed and MEDLINE, focusing on the treatment of TB. Ongoing clinical trials were listed according to the authors' knowledge and completed consulting clinicaltrials.gov and other publicly available websites (www.resisttb.org/clinical-trials-progress-report, www.newtbdrugs.org/pipeline/trials).

CONTENT

This review summarizes the recent, major changes in the landscape for drug-susceptible and drug-resistant treatment, with a specific focus on their potential impact on patient outcomes and programmatic TB management. Moreover, insights in host-directed therapies, and advances in pharmacokinetics and pharmacogenomics are discussed. A thorough outline of ongoing therapeutic clinical trials is presented, highlighting different approaches and goals in current TB clinical research.

IMPLICATIONS

Future research should be directed to individualize regimens and protect these recent breakthroughs by preventing and identifying the selection of drug resistance and providing widespread, affordable, patient-centred access to new treatment options for all people affected by TB.

Insight into Population Structure and Drug Resistance of Pediatric Tuberculosis Strains from China and Russia Gained through Whole-Genome Sequencing

This study aimed to determine phenotypic and genotypic drug resistance patterns of Mycobacterium tuberculosis strains from children with tuberculosis (TB) in China and Russia, two high-burden countries for multi/extensively-drug resistant (MDR/XDR) TB. Whole-genome sequencing data of M. tuberculosis isolates from China (n = 137) and Russia (n = 60) were analyzed for phylogenetic markers and drug-resistance mutations, followed by comparison with phenotypic susceptibility data. The Beijing genotype was detected in 126 Chinese and 50 Russian isolates. The Euro-American lineage was detected in 10 Russian and 11 Chinese isolates. In the Russian collection, the Beijing genotype and Beijing B0/W148-cluster were dominated by MDR strains (68% and 94%, respectively). Ninety percent of B0/W148 strains were phenotypically pre-XDR. In the Chinese collection, neither of the Beijing sublineages was associated with MDR/pre-XDR status. MDR was mostly caused by low fitness cost mutations (rpoB S450L, katG S315T, rpsL K43R). Chinese rifampicin-resistant strains demonstrated a higher diversity of resistance mutations than Russian isolates (p = 0.003). The rifampicin and isoniazid resistance compensatory mutations were detected in some MDR strains, but they were not widespread. The molecular mechanisms of M. tuberculosis adaptation to anti-TB treatment are not unique to the pediatric strains, but they reflect the general situation with TB in Russia and China.

Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a 2023 TBnet/RESIST-TB consensus statement

Drug-resistant tuberculosis is a substantial health-care concern worldwide. Despite culture-based methods being considered the gold standard for drug susceptibility testing, molecular methods provide rapid information about the Mycobacterium tuberculosis mutations associated with resistance to anti-tuberculosis drugs. This consensus document was developed on the basis of a comprehensive literature search, by the TBnet and RESIST-TB networks, about reporting standards for the clinical use of molecular drug susceptibility testing. Review and the search for evidence included hand-searching journals and searching electronic databases. The panel identified studies that linked mutations in genomic regions of M tuberculosis with treatment outcome data. Implementation of molecular testing for the prediction of drug resistance in M tuberculosis is key. Detection of mutations in clinical isolates has implications for the clinical management of patients with multidrug-resistant or rifampicin-resistant tuberculosis, especially in situations when phenotypic drug susceptibility testing is not available. A multidisciplinary team including clinicians, microbiologists, and laboratory scientists reached a consensus on key questions relevant to molecular prediction of drug susceptibility or resistance to M tuberculosis, and their implications for clinical practice. This consensus document should help clinicians in the management of patients with tuberculosis, providing guidance for the design of treatment regimens and optimising outcomes.

Long-term treatment outcomes in patients with multidrug-resistant tuberculosis

OBJECTIVES

To describe long-term treatment outcomes in patients with multi-drug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB) and validate established outcome definitions for MDR/RR-TB treatment.

METHODS

Among patients with MDR/RR-TB admitted to a German MDR/RR-TB referral centre from 1 September 2002 to 29 February 2020, we compared long-term treatment outcomes derived from individual patient follow-up with treatment outcomes defined by WHO-2013, WHO-2021 and the Tuberculosis Network European Trials Group-2016.

RESULTS

In a total of 163 patients (mean age, 35 years; standard deviation, 13 years; 14/163 [8.6%] living with HIV; 109/163 [66.9%] men, 149/163 [91.4%] migrating to Germany within 5 years), the treatment of culture-confirmed MDR/RR-TB was initiated. Additional drug resistance to a fluoroquinolone or a second-line injectable agent was present in 15 of the 163 (9.2%) Mycobacterium tuberculosis strains; resistance against both the drug classes was present in 29 of the 163 (17.8%) strains. The median duration of MDR/RR-TB treatment was 20 months (interquartile range, 19.3-21.6 months), with a medium of five active drugs included. The median follow-up time was 4 years (47.7 months; interquartile range, 21.7-65.8 months). Among the 163 patients, cure was achieved in 25 (15.3%), 82 (50.3%) and 95 (58.3%) patients according to the outcome definitions of WHO-2013, WHO-2021, and the Tuberculosis Network European Trials Group-2016, respectively. The lost to follow-up rate was 17 of 163 (10.4%). Death was more likely in patients living with HIV (hazard ratio, 4.28; 95% confidence interval, 1.26-12.86) and older patients (hazard ratio, 1.08; 95% confidence interval, 1.05-1.12; increment of 1 year). Overall, 101/163 (62.0%) patients experienced long-term, relapse-free cure; of those, 101/122 (82.8%) patients with a known status (not lost to-follow-up or transferred out) at follow-up.

CONCLUSION

Under optimal management conditions leveraging individualized treatment regimens, long-term, relapse-free cure from MDR/RR-TB is substantially higher than cure rates defined by current treatment outcome definitions.