Pretomanid is a key anti-TB drug included in the WHO list of essential medications. The current EMA-approved label for pretomanid restricts its use to the regimen comprising bedaquiline, pretomanid and linezolid (BPaL) and only for extensively drug-resistant-TB or multidrug-resistant TB, "when antibiotics used for the latter form of TB do not work or cause unacceptable side effects." This restricted use implies that the older, prolonged and poorly tolerated regimens remain the recommended treatment for most cases of drug-resistant TB. The authors, representing many respiratory groups and societies, call for the label expansion of pretomanid to align with global guidelines, allowing for broader use.
BACKGROUND
New 6-month rifampicin-resistant tuberculosis treatment regimens containing bedaquiline, pretomanid, and linezolid (BPaL) with or without moxifloxacin or clofazimine, could improve treatment efficacy, safety, and tolerability, and free up resources within the health system. Following a change to WHO rifampicin-resistant tuberculosis treatment guidelines, countries are facing difficult decisions about when and how to incorporate new drug regimens into national guidelines. We aimed to assess the probability of BPaL-based regimens being cost-saving using data collected in the TB-PRACTECAL trial.
METHODS
This economic evaluation using a cost-utility analysis was embedded in five TB-PRACTECAL trial sites in Belarus, Uzbekistan, and South Africa. Between Nov 19, 2020, and Sept 27, 2022, we collected detailed primary unit cost data in six hospitals and four ambulatory health facilities and collected data on patient-incurred costs from 73 trial participants. The primary efficacy endpoint of the main trial, a composite of unfavourable outcomes (death, disease recurrence, treatment failure, early discontinuation of therapy, withdrawal, or loss to follow-up) and clinically important safety outcomes by 72 weeks of follow-up were incorporated into the analysis. Societal perspective cost data and effect outcome data were input into a Markov model to estimate the cost per disability-adjusted life-year (DALY) averted by BPaL-based regimens compared with the standard of care over a 20-year time horizon. We conducted a range of univariate and probabilistic sensitivity analyses to test our findings.
FINDINGS
BPaL-based regimens averted a mean of 1·28 DALYs and saved a mean of US$14 868 (SD 291) per person from the provider perspective compared with standard-of-care regimens over 20 years. Patient-incurred costs were reduced by a mean of $172 (SD 0·84) in BPaL-based regimen groups compared with standard of care. The main cost drivers for both providers and patients were inpatient bed-days; the duration of the inpatient period varied across countries. Varying a range of model parameters affected the degree of cost savings but did not change the finding that BPaL-based regimens are cost-saving compared with standard of care.
INTERPRETATION
This trial-based evidence adds to consistent indications from modelling studies that BPaL-based regimens are cost-saving for both the patient and health system. Urgent implementation of BPaL-based regimens in countries with a high burden of tuberculosis could improve treatment of rifampicin-resistant tuberculosis, reduce pill burden, and free up desperately needed resources within the health system.
BACKGROUND
For decades, poor treatment options and low-quality evidence plagued care for patients with rifampin-resistant tuberculosis. The advent of new drugs to treat tuberculosis and enhanced funding now permit randomized, controlled trials of shortened-duration, all-oral treatments for rifampin-resistant tuberculosis.
METHODS
We conducted a phase 3, multinational, open-label, randomized, controlled noninferiority trial to compare standard therapy for treatment of fluoroquinolone-susceptible, rifampin-resistant tuberculosis with five 9-month oral regimens that included various combinations of bedaquiline (B), delamanid (D), linezolid (L), levofloxacin (Lfx) or moxifloxacin (M), clofazimine (C), and pyrazinamide (Z). Participants were randomly assigned (with the use of Bayesian response-adaptive randomization) to receive one of five combinations or standard therapy. The primary end point was a favorable outcome at week 73, defined by two negative sputum culture results or favorable bacteriologic, clinical, and radiologic evolution. The noninferiority margin was -12 percentage points.
RESULTS
Among the 754 participants who underwent randomization, 699 were included in the modified intention-to-treat analysis, and 562 in the per-protocol analysis. In the modified intention-to-treat analysis, 80.7% of the patients in the standard-therapy group had favorable outcomes. The risk difference between standard therapy and each of the four new regimens that were found to be noninferior in the modified intention-to-treat population was as follows: BCLLfxZ, 9.8 percentage points (95% confidence interval [CI], 0.9 to 18.7); BLMZ, 8.3 percentage points (95% CI, -0.8 to 17.4); BDLLfxZ, 4.6 percentage points (95% CI, -4.9 to 14.1); and DCMZ, 2.5 percentage points (95% CI, -7.5 to 12.5). Differences were similar in the per-protocol population, with the exception of DCMZ, which was not noninferior in that population. The proportion of participants with grade 3 or higher adverse events was similar across the regimens. Grade 3 or higher hepatotoxic events occurred in 11.7% of participants overall and in 7.1% of those receiving standard therapy.
CONCLUSIONS
Consistent results across all the analyses support the noninferior efficacy of three all-oral shortened regimens for the treatment of rifampin-resistant tuberculosis. (Funded by Unitaid and others; endTB ClinicalTrials.gov number, NCT02754765.).
Tuberculosis (TB) is a major public health challenge encountered across many Médecins Sans Frontières (MSF) fields. Management of drug-resistant TB is an operational priority for MSF. endTB is an MSF-sponsored randomised trial funded by Unitaid as part of the larger endTB project. The trial objective was to examine five new all-oral, shortened regimens for patients with fluoroquinolone-susceptible, rifampicin-resistant/multidrug- resistant TB (RR/MDR-TB).
METHODS
endTB was a phase 3, randomised, controlled, non-inferiority trial performed in seven countries (Georgia, India, Kazakhstan, Lesotho, Pakistan, Peru, and South Africa) in five WHO regions. Participants with RR/MDR-TB (aged ≥15 years old) were randomly assigned to six regimen groups (1:1:1:1:1:1; 9BLMZ, 9BCLLfxZ, 9BDLLfxZ, 9DCLLfxZ, 9DCMZ, or control) using Bayesian response-adapted randomisation. Experimental regimens were 9 months long; all contained 4–5 drugs, including pyrazinamide, a fluoroquinolone, either bedaquiline and/or delamanid, and linezolid and/or clofazimine. The internal, concurrent control regimen was the evolving WHO- recommended standard. Primary outcome was the proportion of favourable outcome at week 73, defined by two negative sputum culture results. The non-inferiority margin was 12%. We performed efficacy comparisons in the modified intention-to-treat population (mITT), which included all randomised participants who took at least one dose of study treatment (safety population) and who had a positive pre-randomisation TB culture, and in the per-protocol population (PP), defined as mITT excluding participants who did not receive the protocol-defined treatment. We performed safety comparisons on the safety population. This study is registered on ClinicalTrials.gov (NCT02754765).
RESULTS
Of 754 participants enrolled between 2017 and 2021, 696 and 559 were included in the mITT and PP analyses, respectively. Median age was 32.0 years (IQR 23.0–44.0), and 264 (38%) of 696 participants were female. Overall, regimens 9BLLfxCZ, 9BLMZ, and 9BDLLfxZ achieved non-inferiority in mITT and PP analyses. 9BLLfxCZ also achieved superiority. 9DCMZ regimen achieved non-inferiority in mITT, but not in PP. 9DCLLfxZ did not achieve non-inferiority. The proportion of participants experiencing grade 3 or higher adverse events or serious adverse events was similar between the regimens. Grade 3 or higher hepatotoxicity occurred in 12.6% (78/619) of participants in the experimental regimens overall and in 7.1% (9/126) of participants in the control group.
CONCLUSION
The endTB trial results increase patient-centred treatment options for RR/MDR-TB with three shortened, all-oral, non- inferior regimens to a current well-performing standard of care. A fourth regimen could be considered for patients for whom bedaquiline and/or linezolid is not available. These results could be extrapolated to children and pregnant women. The implications on the MSF TB field activities are important and could lead to improved access to care and better treatment outcome.
Effectiveness, safety, tolerability, and adherence are critical considerations in shifting to shorter tuberculosis (TB) regimens. Novel 6-month oral regimens that include bedaquiline (B), pretomanid (Pa), and linezolid (L), with or without a fourth drug, have been shown to be as or more effective than the established longer regimens for the treatment of multidrug-resistant/rifampicin-resistant TB (MDR/RR-TB). We aimed to evaluate the safety and tolerability of linezolid in BPaL-containing regimens for the treatment of MDR/RR-TB among recently completed clinical trials.
METHODS
A review and meta-analysis was undertaken including published and unpublished data from clinical trials, conducted between 2010 and 2021, that evaluated regimens containing BPaL for the treatment of MDR/RR-TB. Individual patient data were obtained. For each BPaL-containing regimen, we evaluated the frequency and severity of treatment-related adverse events. The risk difference of adverse events for each regimen was calculated, in comparison to patients assigned to receiving the lowest cumulative exposure of linezolid.
RESULTS
Data from 3 clinical trials investigating 8 unique BPaL-containing regimens were included, comprising a total of 591 participants. Adverse events were more frequent in groups randomized to a higher cumulative linezolid dose. Among patients who were randomized to a daily dose of 1200 mg linezolid, 68 of 195 (35%) experienced a grade 3–4 adverse event versus 89 of 396 (22%) patients receiving BPaL-containing regimens containing 600 mg linezolid.
CONCLUSIONS
Regimens containing BPaL were relatively well tolerated when they included a daily linezolid dose of 600 mg. These novel regimens promise to improve the tolerability of treatment for MDR/RR-TB.
Around 500,000 people worldwide develop rifampicin-resistant tuberculosis each year. The proportion of successful treatment outcomes remains low and new treatments are needed. Following an interim analysis, we report the final safety and efficacy outcomes of the TB-PRACTECAL trial, evaluating the safety and efficacy of oral regimens for the treatment of rifampicin-resistant tuberculosis.
METHODS
This open-label, randomised, controlled, multi-arm, multicentre, non-inferiority trial was conducted at seven hospital and community sites in Uzbekistan, Belarus, and South Africa, and enrolled participants aged 15 years and older with pulmonary rifampicin-resistant tuberculosis. Participants were randomly assigned, in a 1:1:1:1 ratio using variable block randomisation and stratified by trial site, to receive 36-80 week standard care; 24-week oral bedaquiline, pretomanid, and linezolid (BPaL); BPaL plus clofazimine (BPaLC); or BPaL plus moxifloxacin (BPaLM) in stage one of the trial, and in a 1:1 ratio to receive standard care or BPaLM in stage two of the trial, the results of which are described here. Laboratory staff and trial sponsors were masked to group assignment and outcomes were assessed by unmasked investigators. The primary outcome was the percentage of participants with a composite unfavourable outcome (treatment failure, death, treatment discontinuation, disease recurrence, or loss to follow-up) at 72 weeks after randomisation in the modified intention-to-treat population (all participants with rifampicin-resistant disease who received at least one dose of study medication) and the per-protocol population (a subset of the modified intention-to-treat population excluding participants who did not complete a protocol-adherent course of treatment (other than because of treatment failure or death) and those who discontinued treatment early because they violated at least one of the inclusion or exclusion criteria). Safety was measured in the safety population. The non-inferiority margin was 12%. This trial is registered with ClinicalTrials.gov, NCT02589782, and is complete.
FINDINGS
Between Jan 16, 2017, and March 18, 2021, 680 patients were screened for eligibility, of whom 552 were enrolled and randomly assigned (152 to the standard care group, 151 to the BPaLM group, 126 to the BPaLC group, and 123 to the BPaL group). The standard care and BPaLM groups proceeded to stage two and are reported here, post-hoc analyses of the BPaLC and BPaL groups are also reported. 151 participants in the BPaLM group and 151 in the standard care group were included in the safety population, with 138 in the BPaLM group and 137 in the standard care group in the modified intention-to-treat population. In the modified intention-to-treat population, unfavourable outcomes were reported in 16 (12%) of 137 participants for whom outcome was assessable in the BPaLM group and 56 (41%) of 137 participants in the standard care group (risk difference -29·2 percentage points [96·6% CI -39·8 to -18·6]; non-inferiority and superiority p<0·0001). 34 (23%) of 151 participants receiving BPaLM had adverse events of grade 3 or higher or serious adverse events, compared with 72 (48%) of 151 participants receiving standard care (risk difference -25·2 percentage points [96·6% CI -36·4 to -13·9]). Five deaths were reported in the standard care group by week 72, of which one (COVID-19 pneumonia) was unrelated to treatment and four (acute pancreatitis, suicide, sudden death, and sudden cardiac death) were judged to be treatment-related.
INTERPRETATION
The 24-week, all-oral BPaLM regimen is safe and efficacious for the treatment of pulmonary rifampicin-resistant tuberculosis, and was added to the WHO guidance for treatment of this condition in 2022. These findings will be key to BPaLM becoming the preferred regimen for adolescents and adults with pulmonary rifampicin-resistant tuberculosis.
BACKGROUND
After a history of poor treatments for rifampin-resistant tuberculosis (RR-TB), recent advances have resulted in shorter, more effective treatments. However, they are not available to everyone and have shortcomings, requiring additional treatment options.
METHODS
endTB is an international, open-label, Phase 3 non-inferiority, randomized, controlled clinical trial to compare five 9-month all-oral regimens including bedaquiline (B), delamanid (D), linezolid (L), levofloxacin (Lfx) or moxifloxacin (M), clofazimine (C) and pyrazinamide (Z), to the standard (control) for treatment of fluoroquinolone-susceptible RR-TB. Participants were randomized to 9BLMZ, 9BCLLfxZ, 9BDLLfxZ, 9DCLLfxZ, 9DCMZ and control using Bayesian response-adaptive randomization. The primary outcome was favorable outcome at week 73 defined by two negative sputum culture results or by favorable bacteriologic, clinical and radiologic evolution. The non-inferiority margin was 12 percentage points.
RESULTS
Of 754 randomized patients, 696 and 559 were included in the modified intention to treat (mITT) and per-protocol (PP) analyses, respectively. In mITT, the control had 80.7% favorable outcomes. Regimens 9BCLLfxZ [adjusted risk difference (aRD): 9.5% (95% confidence interval (CI), 0.4 to 18.6)], 9BLMZ [aRD: 8.8% (95%CI, −0.6 to 18.2)], and 9BDLLfxZ [3.9% (95%CI, −5.8 to 13.6)] were non-inferior in mITT and in PP. The proportion of participants experiencing grade 3 or higher adverse events was similar across the regimens. Grade 3 or higher hepatotoxicity occurred in 11.7% of the experimental regimens overall and in 7.1% of the control.
CONCLUSIONS
The endTB trial increases treatment options for RR-TB with three shortened, all-oral regimens that were non-inferior to a current well-performing standard of care.
The value, speed of completion and robustness of the evidence generated by TB treatment trials could be improved by implementing standards for best practice.
METHODS
A global panel of experts participated in a Delphi process, using a 7-point Likert scale to score and revise draft standards until consensus was reached.
RESULTS
Eleven standards were defined: Standard 1, high quality data on TB regimens are essential to inform clinical and programmatic management; Standard 2, the research questions addressed by TB trials should be relevant to affected communities, who should be included in all trial stages; Standard 3, trials should make every effort to be as inclusive as possible; Standard 4, the most efficient trial designs should be considered to improve the evidence base as quickly and cost effectively as possible, without compromising quality; Standard 5, trial governance should be in line with accepted good clinical practice; Standard 6, trials should investigate and report strategies that promote optimal engagement in care; Standard 7, where possible, TB trials should include pharmacokinetic and pharmacodynamic components; Standard 8, outcomes should include frequency of disease recurrence and post-treatment sequelae; Standard 9, TB trials should aim to harmonise key outcomes and data structures across studies; Standard 10, TB trials should include biobanking; Standard 11, treatment trials should invest in capacity strengthening of local trial and TB programme staff.
CONCLUSION
These standards should improve the efficiency and effectiveness of evidence generation, as well as the translation of research into policy and practice.