Cost-effectiveness of bedaquiline, pretomanid and linezolid for treatment of extensively drug-resistant tuberculosis in South Africa, Georgia and the Philippines

A systematic review of economic evaluations of pharmacological treatments for active tuberculosis

Objectives

The continuing spread of tuberculosis (TB) worldwide, especially drug-resistant TB, poses a major challenge to healthcare systems globally. Addressing this requires appraising the cost effectiveness of existing pharmacological interventions against TB to identify key drivers of cost effectiveness and value and guide pharmaceutical innovation and novel drug regimen development.

Methods

Studies were identified from a search of six database: MEDLINE MEDLINE-In Process, MEDLINE Epub Ahead of Print, EMBASE, Cochrane Database of Systematic Reviews, and Econlit in July 2022. Two reviewers independently assessed all identified studies and reports using pre-defined inclusion/exclusion criteria. Study methodological quality was assessed, data were extracted in standard tables, and results were narratively synthesized.

Results

Overall, 991 studies and 53 HTA reports were identified with 20 studies and 3 HTA reports meeting the inclusion criteria. Quality assessment of the 20 studies identified 4 with minor limitations, while the remainder were assessed as having potentially or very serious limitations. Sixteen studies conducted cost-utility analyses, 6 conducted cost-effectiveness analyses, and 2 conducted cost-comparison analyses with some studies performing multiple analyses. The majority (n = 16) were model-based. Eleven studies analyzed the cost-effectiveness of bedaquiline, 6 compared shorter to longer/standard duration regimens, 2 assessed ethambutol, and 1 assessed delamanid. Key drivers of cost effectiveness were drug costs, the number of TB cases, the portion of cases with sputum culture conversion, treatment delivery costs, and treatment efficacy. Common value elements considered included adverse events, drug resistance, and improving treatment adherence.

Conclusion

Our results suggest that out of the pharmacological treatments assessed, bedaquiline is likely a cost-effective addition to existing treatment regimens/background treatment regimens, while ethambutol is not likely to be. Newer shorter regimens, even if more costly, seem to be more cost-effective compared to longer regimens. These results illustrate the limited number of novel cost-effective pharmacological interventions and highlight a need to develop new drugs/regimens against TB to overcome resistance, taking into account the key drivers of cost effectiveness and other value attributes identified from this review.

Pathogenicity and virulence of Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, an infectious disease with one of the highest morbidity and mortality rates worldwide. Leveraging its highly evolved repertoire of non-protein and protein virulence factors, Mtb invades through the airway, subverts host immunity, establishes its survival niche, and ultimately escapes in the setting of active disease to initiate another round of infection in a naive host. In this review, we will provide a concise synopsis of the infectious life cycle of Mtb and its clinical and epidemiologic significance. We will also take stock of its virulence factors and pathogenic mechanisms that modulate host immunity and facilitate its spread. Developing a greater understanding of the interface between Mtb virulence factors and host defences will enable progress toward improved vaccines and therapeutics to prevent and treat tuberculosis.

GRADE guidance 23: considering cost-effectiveness evidence in moving from evidence to health-related recommendations

BACKGROUND

This is the 23rd in a series of articles describing the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to grading the certainty of evidence and strength of recommendations for systematic reviews, health technology assessments, and clinical guideline development.

OBJECTIVES

We outline how resource utilization and cost-effectiveness analyses are integrated into health-related recommendations, using the GRADE Evidence to Decision (EtD) frameworks.

STUDY DESIGN AND SETTING

Through iterative discussions and refinement, in-person, and online meetings, and through e-mail communication, we developed draft guidance to incorporate economic evidence in the formulation of health-related recommendations. We developed scenarios to operationalize the guidance. We presented a summary of the results to members of the GRADE Economic Evaluation Project Group.

RESULTS

We describe how to estimate the cost of preventing (or achieving) an event to inform assessments of cost-effectiveness of alternative treatments, when there are no published economic evaluations. Evidence profiles and Summary of Findings tables based on systematic reviews of cost-effectiveness analyses can be created to provide top-level summaries of results and quality of multiple published economic evaluations. We also describe how this information could be integrated in GRADE's EtD frameworks to inform health-related recommendations. Three scenarios representing various levels of available cost-effectiveness evidence were used to illustrate the integration process.

CONCLUSION

This GRADE guidance provides practical information for presenting cost-effectiveness data and its integration in the development of health-related recommendations, using the EtD frameworks.

Cost-Effectiveness of All-Oral Regimens for the Treatment of Multidrug-Resistant Tuberculosis in Korea: Comparison With Conventional Injectable-Containing Regimens

BACKGROUND

Regimens for the treatment of multidrug-resistant tuberculosis (MDR-TB) have been changed from injectable-containing regimens to all-oral regimens. The economic effectiveness of new all-oral regimens compared with conventional injectable-containing regimens was scarcely evaluated. This study was conducted to compare the cost-effectiveness between all-oral longer-course regimens (the oral regimen group) and conventional injectable-containing regimens (the control group) to treat newly diagnosed MDR-TB patients.

METHODS

A health economic analysis over lifetime horizon (20 years) from the perspective of the healthcare system in Korea was conducted. We developed a combined simulation model of a decision tree model (initial two years) and two Markov models (remaining 18 years, six-month cycle length) to calculate the incremental cost-effectiveness ratio (ICER) between the two groups. The transition probabilities and cost in each cycle were assumed based on the published data and the analysis of health big data that combined country-level claims data and TB registry in 2013-2018.

RESULTS

The oral regimen group was assumed to spend 20,778 USD more and lived 1.093 years or 1.056 quality-adjusted life year (QALY) longer than the control group. The ICER of the base case was calculated to be 19,007 USD/life year gained and 19,674 USD/QALY. The results of sensitivity analyses showed that base case results were very robust and stable, and the oral regimen was cost-effective with a 100% probability for a willingness to pay more than 21,250 USD/QALY.

CONCLUSION

This study confirmed that the new all-oral longer regimens for the treatment of MDR-TB were cost-effective in replacing conventional injectable-containing regimens.

Updated considerations in the diagnosis and management of tuberculosis infection and disease: integrating the latest evidence-based strategies

INTRODUCTION

Tuberculosis (TB) is a leading infectious cause of global morbidity and mortality, affecting nearly a quarter of the human population and accounting for over 10 million deaths each year. Over the past several decades, TB incidence and mortality have gradually declined, but 2021 marked a threatening reversal of this trend highlighting the importance of accurate diagnosis and effective treatment of all forms of TB.

AREAS COVERED

This review summarizes advances in TB diagnostics, addresses the treatment of people with TB infection and TB disease including recent evidence for treatment regimens for drug-susceptible and drug-resistant TB, and draws attention to special considerations in children and during pregnancy.

EXPERT OPINION

Improvements in diagnosis and management of TB have expanded the available options for TB control. Molecular testing has enhanced the detection of TB disease, but better diagnostics are still needed, particularly for certain populations such as children. Novel treatment regimens have shortened treatment and improved outcomes for people with TB. However, important questions remain regarding the optimal management of TB. Work must continue to ensure the potential of the latest developments is realized for all people affected by TB.

Programmatic management of rifampicin-resistant tuberculosis with standard regimen in Cameroon: a retrospective cohort study

OBJECTIVES

To describe treatment outcomes for rifampicin-resistant tuberculosis (Rr-TB) started on standard regimen and the frequency of acquired drug resistance in patients treated using the standard treatment regimen (STR) in Cameroon between 2015-2019.

METHODS

This is a retrospective cohort study. Rr-TB patients were initiated on the STR, including a fluoroquinolone (FQ), a second-line injectable drug (SLI), and companion drugs. In case of resistance to fluoroquinolones (FQr) at baseline, FQ, SLI and ethionamide were replaced by bedaquiline, delamanid, and linezolid in a modified treatment regimen (mTR), FQr-mTR. In case of resistance to SLI (SLIr) at baseline, SLI was replaced by linezolid (LZD), SLIr-mTR. Logistic regression and competing risk regression were used to estimate predictors of early (first eight weeks) mortality and overall mortality, respectively.

RESULTS

Of 709 patients started on a standard regimen, treatment success occurred in 84.7% (587/693), 72.7% (8/11) and 100% (10/10) of patients treated with STR, FQr-mTR and SLIr-mTR as final regimens, respectively. Three (0.6%) patients acquired FQr during treatment. Early mortality occurred in 4.1% (29/709) and was associated with being HIV positive, male sex and being underweight. Overall mortality was associated with missing drug-susceptibility testing results at baseline, being HIV positive, age>40 and male sex.

CONCLUSION

Programmatic management of Rr-TB, with additional second-line drug resistance treated with mTR, resulted in excellent treatment outcomes.

Cost-effectiveness of short, oral treatment regimens for rifampicin resistant tuberculosis

Current options for treating tuberculosis (TB) that is resistant to rifampicin (RR-TB) are few, and regimens are often long and poorly tolerated. Following recent evidence from the TB-PRACTECAL trial countries are considering programmatic uptake of 6-month, all-oral treatment regimens. We used a Markov model to estimate the incremental cost-effectiveness of three regimens containing bedaquiline, pretomanid and linezolid (BPaL) with and without moxifloxacin (BPaLM) or clofazimine (BPaLC) compared with the current mix of long and short standard of care (SOC) regimens to treat RR-TB from the provider perspective in India, Georgia, Philippines, and South Africa. We estimated total costs (2019 USD) and disability-adjusted life years (DALYs) over a 20-year time horizon. Costs and DALYs were discounted at 3% in the base case. Parameter uncertainty was tested with univariate and probabilistic sensitivity analysis. We found that all three regimens would improve health outcomes and reduce costs compared with the current programmatic mix of long and short SOC regimens in all four countries. BPaL was the most cost-saving regimen in all countries, saving $112-$1,173 per person. BPaLM was the preferred regimen at a willingness to pay per DALY of 0.5 GDP per capita in all settings. Our findings indicate BPaL-based regimens are likely to be cost-saving and more effective than the current standard of care in a range of settings. Countries should consider programmatic uptake of BPaL-based regimens.

Pretomanid for tuberculosis treatment: an update for clinical purposes

Coronavirus disease (COVID-19) pandemic determined a 10 years-set back in tuberculosis (TB) control programs. Recent advances in available therapies may help recover the time lost. While Linezolid (LZD) and Bedaquiline (BDQ), previously Group D second line drugs (SLDs) for TB, have been relocated to Group A, other drugs are currently being studied in regimens for drug resistant TB (DR-TB). Among these, Pretomanid (PA), a recently introduced antimycobacterial drug derived from nitroimidazole with both solid bactericidal and bacteriostatic effect, and with an excellent effectiveness and tolerability profile, is in the spotlight. Following promising data obtained from recently published and ongoing randomized controlled trials (RCTs), the World Health Organization (WHO) determined to include PA in its guidelines for the treatment of rifampicin-resistant (RR), multi drug resistant (MDR) and pre-extensively drug resistant TB (pre-XDR-TB) with BDQ, LZD and Moxifloxacine (MFX) in a 6-month regimen. Although further studies on the subject are needed, PA may also represent a treatment option for drug-susceptible TB (DS-TB), latent TB infection (LTBI) and non tuberculous mycobacteria (NTM). This narrative review aims to examine current implementation options and future possibilities for PA in the never-ending fight against TB.