Clinical standards for the management of adverse effects during treatment for TB

BACKGROUND: Adverse effects (AE) to TB treatment cause morbidity, mortality and treatment interruption. The aim of these clinical standards is to encourage best practise for the diagnosis and management of AE.METHODS: 65/81 invited experts participated in a Delphi process using a 5-point Likert scale to score draft standards.RESULTS: We identified eight clinical standards. Each person commencing treatment for TB should: Standard 1, be counselled regarding AE before and during treatment; Standard 2, be evaluated for factors that might increase AE risk with regular review to actively identify and manage these; Standard 3, when AE occur, carefully assessed and possible allergic or hypersensitivity reactions considered; Standard 4, receive appropriate care to minimise morbidity and mortality associated with AE; Standard 5, be restarted on TB drugs after a serious AE according to a standardised protocol that includes active drug safety monitoring. In addition: Standard 6, healthcare workers should be trained on AE including how to counsel people undertaking TB treatment, as well as active AE monitoring and management; Standard 7, there should be active AE monitoring and reporting for all new TB drugs and regimens; and Standard 8, knowledge gaps identified from active AE monitoring should be systematically addressed through clinical research.CONCLUSION: These standards provide a person-centred, consensus-based approach to minimise the impact of AE during TB treatment.

Relative bioavailability of delamanid 50 mg tablets dispersed in water in healthy adult volunteers

AIM

Delamanid is a novel drug for the treatment of drug-resistant tuberculosis, manufactured as 50-mg solid and 25-mg dispersible tablets. We evaluated the effects of dispersing the 50-mg tablet, focusing on the relative bioavailability.

METHODS

Delamanid, 50-mg tablets administered dispersed vs swallowed whole, was investigated in a phase I, four-period, crossover study. Two of three dose strengths of delamanid (25, 50 or 100 mg) were given to healthy adult participants, in both whole and dispersed forms, with a 7-day washout period. Blood samples were collected over 168 h after each dose. Delamanid and its metabolite DM-6705 were analysed with a validated liquid chromatography tandem mass spectrometry assay. The pharmacokinetics of both analytes were analysed using nonlinear mixed-effect modelling. Palatability and acceptability were determined using a standardized questionnaire.

RESULTS

Twenty-four participants completed the study. The bioavailability of dispersed tablets was estimated to be 107% of whole tablets, with a 90% confidence interval of 99.7-114%, fulfilling bioequivalence criteria. The two formulations were not significantly different regarding either bioavailability or its variability. Bioavailability increased at lower doses, by 34% (26-42%) at 50 mg and by 74% (64-86%) at 25 mg, relative to 100 mg. The majority of participants (93%) found the dispersed formulation acceptable in palatability across all delamanid doses.

CONCLUSIONS

Dispersed 50-mg delamanid tablets have similar bioavailability to tablets swallowed whole in adult volunteers. This can be an option for children and other patients who cannot swallow whole tablets, improving access to treatment.

Clinical standards for the dosing and management of TB drugs

BACKGROUND: Optimal drug dosing is important to ensure adequate response to treatment, prevent development of drug resistance and reduce drug toxicity. The aim of these clinical standards is to provide guidance on 'best practice´ for dosing and management of TB drugs.METHODS: A panel of 57 global experts in the fields of microbiology, pharmacology and TB care were identified; 51 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all participants.RESULTS: Six clinical standards were defined: Standard 1, defining the most appropriate initial dose for TB treatment; Standard 2, identifying patients who may be at risk of sub-optimal drug exposure; Standard 3, identifying patients at risk of developing drug-related toxicity and how best to manage this risk; Standard 4, identifying patients who can benefit from therapeutic drug monitoring (TDM); Standard 5, highlighting education and counselling that should be provided to people initiating TB treatment; and Standard 6, providing essential education for healthcare professionals. In addition, consensus research priorities were identified.CONCLUSION: This is the first consensus-based Clinical Standards for the dosing and management of TB drugs to guide clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment to improve patient care.

Pediatric COVID-19 Therapeutics: Seizing the Right Research and Development Opportunities to Accelerate Access for Children

Children, although at lower risk of poor outcomes from COVID-19 relative to adults, still stand to benefit from therapeutic interventions. Understanding of COVID-19 clinical presentation and prognosis in children is essential to optimize therapeutic trials design. This perspective illustrates how to collectively accelerate pediatric COVID-19 therapeutic research and development, based on the experience of the Global Accelerator for Paediatric Formulations.

Injectable-free regimens containing bedaquiline, delamanid, or both for adolescents with rifampicin-resistant tuberculosis in Khayelitsha, South Africa

BACKGROUND

Limited data exist on the use of bedaquiline and delamanid in adolescents with rifampicin-resistant tuberculosis (RR-TB). We describe RR-TB treatment of adolescents (10-19 years) with injectable-free regimens containing these drugs in Khayelitsha, South Africa.

METHODS

This retrospective study included adolescents initiating injectable-free RR-TB treatment regimens containing bedaquiline and/or delamanid from February 2015 to June 2018. We report adverse events (AEs) of interest, sputum culture conversion (SCC), and final end-of-treatment outcomes.

FINDINGS

Twenty-two patients were included; median age at treatment initiation was 17 years (interquartile range [IQR] 15-18), and six (27%) were HIV-positive (median CD4 count 191 cells/mm3 [IQR 157-204]). Eight (36%) patients had RR-TB with fluoroquinolone resistance; ten (45%), eight (36%), and four (18%) patients received regimens containing bedaquiline, delamanid, or the combination of bedaquiline and delamanid, respectively. The median durations of exposure to bedaquiline and delamanid were 5·6 (IQR 5·5-8·4) and 9·4 (IQR 5·9-14·4) months, respectively. There were 49 AEs of interest which occurred in 17 (77%) patients. Fourteen (64%) patients had pulmonary TB with positive sputum cultures at bedaquiline and/or delamanid initiation; among these SCC at month 6 was 79%. Final end-of-treatment outcomes for the 22 adolescent were: 17 (77%) successfully treated, two (9%) lost-to-follow-up, two (9%) treatment failed, and one (5%) died.

INTERPRETATION

This study found that injectable-free regimens containing bedaquiline and/or delamanid in a programmatic setting were effective and well tolerated in adolescents and should be routinely provided for RR-TB treatment in this age group as recommended by the World Health Organisation.

Willingness to Take Multidrug-resistant Tuberculosis (MDR-TB) Preventive Therapy Among Adult and Adolescent Household Contacts of MDR-TB Index Cases: An International Multisite Cross-sectional Study

BACKGROUND

Household contacts (HHCs) of individuals with multidrug-resistant tuberculosis (MDR-TB) are at high risk of infection and subsequent disease. There is limited evidence on the willingness of MDR-TB HHCs to take MDR-TB preventive therapy (MDR TPT) to decrease their risk of TB disease.

METHODS

In this cross-sectional study of HHCs of MDR-TB and rifampicin-resistant tuberculosis (RR-TB) index cases from 16 clinical research sites in 8 countries, enrollees were interviewed to assess willingness to take a hypothetical, newly developed MDR TPT if offered. To identify factors associated with willingness to take MDR TPT, a marginal logistic model was fitted using generalized estimating equations to account for household-level clustering.

RESULTS

From 278 MDR-TB/RR-TB index case households, 743 HHCs were enrolled; the median age of HHCs was 33 (interquartile range, 22-49) years, and 62% were women. HHC willingness to take hypothetical MDR TPT was high (79%) and remained high even with the potential for mild side effects (70%). Increased willingness was significantly associated with current employment or schooling (adjusted odds ratio [aOR], 1.83 [95% confidence interval {CI}, 1.07-3.13]), appropriate TB-related knowledge (aOR, 2.22 [95% CI, 1.23-3.99]), confidence in taking MDR TPT (aOR, 7.16 [95% CI, 3.33-15.42]), and being comfortable telling others about taking MDR TPT (aOR, 2.29 [95% CI, 1.29-4.06]).

CONCLUSIONS

The high percentage of HHCs of MDR-TB/RR-TB index cases willing to take hypothetical MDR TPT provides important evidence for the potential uptake of effective MDR TPT when implemented. Identified HHC-level variables associated with willingness may inform education and counseling efforts to increase HHC confidence in and uptake of MDR TPT.

Feasibility of Identifying Household Contacts of Rifampin-and Multidrug-resistant Tuberculosis Cases at High Risk of Progression to Tuberculosis Disease

BACKGROUND

We assessed multidrug-resistant tuberculosis (MDR-TB) cases and their household contacts (HHCs) to inform the development of an interventional clinical trial.

METHODS

We conducted a cross-sectional study of adult MDR-TB cases and their HHCs in 8 countries with high TB burdens. HHCs underwent symptom screenings, chest radiographies, sputum TB bacteriologies, TB infection (TBI) testing (tuberculin skin test [TST] and interferon gamma release assay [IGRA]), and human immunodeficiency virus (HIV) testing.

RESULTS

From October 2015 to April 2016, 1016 HHCs from 284 MDR-TB cases were enrolled. At diagnosis, 69% of MDR-TB cases were positive for acid-fast bacilli sputum smears and 43% had cavitary disease; at study entry, 35% remained smear positive after a median MDR-TB treatment duration of 8.8 weeks. There were 9 HHCs that were diagnosed with TB prior to entry and excluded. Of the remaining 1007 HHCs, 41% were male and the median age was 25 years. There were 121 (12%) HHCs that had new cases of TB identified: 17 (2%) were confirmed, 33 (3%) probable, and 71 (7%) possible TB cases. The TBI prevalence (defined as either TST or IGRA positivity) was 72% and varied by age, test used, and country. Of 1007 HHCs, 775 (77%) were considered high-risk per these mutually exclusive groups: 102 (10%) were aged <5 years; 63 (6%) were aged ≥5 and were infected with HIV; and 610 (61%) were aged ≥5 years, were negative for HIV or had an unknown HIV status, and were TBI positive. Only 21 (2%) HHCs were on preventive therapy.

CONCLUSIONS

The majority of HHCs in these high-burden countries were at high risk of TB disease and infection, yet few were receiving routine preventive therapy. Trials of novel, preventive therapies are urgently needed to inform treatment policy and practice.

HIV testing uptake among the household contacts of multidrug-resistant tuberculosis index cases in eight countries

SETTING

The household contacts (HHCs) of multidrug-resistant tuberculosis (MDR-TB) index cases are at high risk of tuberculous infection and disease progression, particularly if infected with the human immunodeficiency virus (HIV). HIV testing is important for risk assessment and clinical management.

METHODS

This was a cross-sectional, multi-country study of adult MDR-TB index cases and HHCs. All adult and child HHCs were offered HIV testing if never tested or if HIV-negative >1 year previously when last tested. We measured HIV testing uptake and used logistic regression to evaluate predictors.

RESULTS

A total of 1007 HHCs of 284 index cases were enrolled in eight countries. HIV status was known at enrolment for 226 (22%) HHCs; 39 (4%) were HIV-positive. HIV testing was offered to 769 (98%) of the 781 remaining HHCs; 544 (71%) agreed to testing. Of 535 who were actually tested, 26 (5%) were HIV-infected. HIV testing uptake varied by site (median 86%, range 0-100%; P < 0.0001), and was lower in children aged <18 years than in adults (59% vs. 78%; adjusted for site P < 0.0001).

CONCLUSIONS

HIV testing of HHCs of MDR-TB index cases is feasible and high-yield, with 5% testing positive. Reasons for low test uptake among children and at specific sites-including sites with high HIV prevalence-require further study to ensure all persons at risk for HIV are aware of their status.