A bitter pill to swallow: the need for better medications for drug-resistant tuberculosis in children

Challenging drug-resistant TB treatment journey for children, adolescents and their care-givers: A qualitative study

BACKGROUND

Childhood multidrug-resistant TB (MDR-TB) still affects around 25000 children every year across the globe. Though the treatment success rates for drug-resistant TB (DR-TB) in children are better than adults, children and adolescents face unique hurdles during DR-TB (MDR-TB, Pre-XDR TB and XDR-TB) treatment. This study aimed to understand the patients, guardians and healthcare providers' perspectives about DR-TB treatment journey of patients and caregivers.

METHODS

This is a qualitative study involving in depth-interviews of purposively selected adolescents (n = 6), patients guardians (for children and adolescents, n = 5) and health care providers (n = 8) of Médecins Sans Frontières (MSF) clinic, Mumbai, India. In-depth face to face interviews were conducted in English or Hindi language using interview guides during September-November 2019. The interviews were audio-recorded after consent. Thematic network analysis was used to summarize textual data. ATLAS.ti (version 7) was used for analysis.

RESULT

The age of adolescent patients ranged from 15-19 years and four were female. Five guardians (of three child and two adolescent patients) and eight healthcare providers (including clinicians- 2, DOT providers-2, counselors-2 and programme managers-2) were interviewed. The overarching theme of the analysis was: Challenging DR-TB treatment journey which consisted of four sub-themes: 1) physical-trauma, 2) emotional-trauma, 3) unavailable social-support and 4) non-adapted healthcare services. Difficulties in compounding of drugs were noted for children while adolescents shared experiences around disruption in social life due to disease and treatment. Most of the patients and caregivers experienced treatment fatigue and burnout during the DR-TB treatment. Participants during interviews gave recommendations to improve care.

DISCUSSION

The TB programmes must consider the patient and family as one unit when designing the package of care for paediatric DR-TB. Child and adolescent friendly services (paediatric-formulations, age-specific counselling tools and regular interaction with patients and caregivers) will help minimizing burnout in patients and caregivers.

Challenges and controversies in childhood tuberculosis

Children bear a substantial burden of suffering when it comes to tuberculosis. Ironically, they are often left out of the scientific and public health advances that have led to important improvements in tuberculosis diagnosis, treatment, and prevention over the past decade. This Series paper describes some of the challenges and controversies in paediatric tuberculosis, including the epidemiology and treatment of tuberculosis in children. Two areas in which substantial challenges and controversies exist (ie, diagnosis and prevention) are explored in more detail. This Series paper also offers possible solutions for including children in all efforts to end tuberculosis, with a focus on ensuring that the proper financial and human resources are in place to best serve children exposed to, infected with, and sick from all forms of tuberculosis.

Conducting efficacy trials in children with MDR-TB: what is the rationale and how should they be done?

Paediatric anti-tuberculosis treatment trials have traditionally been limited to Phase I/II studies evaluating the drug pharmacokinetics and safety in children, with assumptions about efficacy made by extrapolating data from adults. However, it is increasingly being recognised that, in some circumstances, efficacy trials are required in children. The current treatment for children with multidrug-resistant tuberculosis (MDR-TB) is long and toxic; shorter, safer regimens, using novel agents, require urgent evaluation. Given the changing pattern of drug metabolism, disease spectrum and rates of TB disease confirmation with age, decisions around inclusion criteria require careful consideration. The most straightforward MDR-TB efficacy trial would include only children with confirmed MDR-TB and no additional drug resistance. Given that it may be unclear at the time treatment is initiated whether the diagnosis will ultimately be confirmed and what the final drug resistance profile will be, this presents a unique challenge in children. Recruiting only these children would, however, limit the generalisability of such a trial, as in reality the majority of children with TB do not have bacteriologically confirmed disease. Given the good existing treatment outcomes with current routine regimens for children with MDR-TB, conducting a superiority trial may not be the optimal design. Demonstrating non-inferiority of efficacy, but superiority with regard to safety, would be an alternative strategy. Using standardised control and experimental MDR-TB treatment regimens is challenging given the wide spectrum of paediatric disease. However, using variable regimens would make interpretation challenging. A paediatric MDR-TB efficacy trial is urgently needed, and with global collaboration and capacity building, is highly feasible.

Partnerships to Design Novel Regimens to Treat Childhood Tuberculosis, Sui Generis: The Road Ahead

There has been a recent expansion of preclinical models to predict the efficacy of regimens to treat adults with tuberculosis. Despite increasing global interest in childhood tuberculosis, these same tools have not been employed to develop pediatric regimens. Children differ from adults in bacillary burden, spectrum of disease, the metabolism and distribution of antituberculosis drugs, and the toxicity experienced. The studies documented in this series describe a proof-of-concept approach to pediatric regimen development. We propose a program of investigation that would take this forward into a systematic and comprehensive method to find optimal drug combinations to use in children, ideal exposures, and required dosing. Although the number of possible drug combinations is extensive, a series of principles could be employed to select likely effective regimens. Regimens should avoid drugs with overlapping toxicity or linked mechanisms of resistance and should aim to include drugs with different mechanisms of action and ones that are able to target different subpopulations of mycobacteria. Finally drugs should penetrate into body sites necessary for treating pediatric disease. At an early stage, this body of work would need to engage with regulatory agencies and bodies that formulate guidelines, so that once regimens and dosages are identified, translation into clinical studies and clinical practice can be rapid. The development of child-friendly drug formulations would need to be carried out in parallel so that pharmacokinetic studies can be undertaken as formulations are created. Significant research and development would be required and a wide range of stakeholders would need to be engaged. The time is right to consider a more thoughtful and systematic approach toward identifying, testing, and comparing combinations of drugs for children with tuberculosis.

Optimizing Research to Speed Up Availability of Pediatric Antiretroviral Drugs and Formulations

Globally 1.8 million children are living with human immunodeficiency virus (HIV), yet only 51% of those eligible actually start treatment. Research and development (R&D) for pediatric antiretrovirals (ARVs) is a lengthy process and lags considerably behind drug development in adults. Providing safe, effective, and well-tolerated drugs for children remains critical to ensuring scale-up globally. We review current approaches to R&D for pediatric ARVs and suggest innovations to enable simplified, faster, and more comprehensive strategies to develop optimal formulations. Several approaches could be adopted, including focusing on a limited number of prioritized formulations and strengthening existing partnerships to ensure that pediatric investigation plans are developed early in the drug development process. Simplified and more efficient mechanisms to undertake R&D need to be put in place, and financing mechanisms must be made more sustainable. Lessons learned from HIV should be shared to support progress in developing pediatric formulations for other diseases, including tuberculosis and viral hepatitis.

Tuberculosis innovations mean little if they cannot save lives

The past decade has seen the emergence of new diagnostics and drugs for tuberculosis, a disease that kills over 1.8 million people each year. However, these new tools are yet to reach scale, and access remains a major challenge for patients in low and middle income countries. Urgent action is needed if we are committed to ending the TB epidemic. This means raising the level of ambition, embracing innovation, increasing financial investments, addressing implementation gaps, and ensuring that new technologies reach those who need them to survive. Otherwise, the promise of innovative technologies will never be realized.

Clinical management of adults and children with multidrug-resistant and extensively drug-resistant tuberculosis

BACKGROUND

Globally there is a burgeoning epidemic of drug monoresistant tuberculosis (TB), multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Almost 20% of all TB strains worldwide are resistant to at least one major TB drug, including isoniazid. In several parts of the world there is an increasing incidence of MDR-TB, and alarmingly, almost a third of MDR-TB cases globally are resistant to either a fluoroquinolone or aminoglycoside. This trend cannot be ignored because drug-resistant TB is associated with greater morbidity compared to drug-susceptible TB, accounts for almost 25% of global TB mortality, is extremely costly to treat, consumes substantial portions of budgets allocated to national TB programmes in TB-endemic countries and is a major threat to healthcare workers, who are already in short supply in resource-poor settings. Even more worrying is the growing epidemic of resistance beyond XDR-TB, including resistance to newer drugs such as bedaquiline and delamanid, as well as the increasing prevalence of programmatically incurable TB in countries like South Africa, Russia, India and China. These developments threaten to reverse the gains already made against TB.

SOURCES

Articles related to MDR-TB and XDR-TB found on PubMed in all languages up to September 2016, published reviews, and files of the authors.

AIM AND CONTENT

To review the clinical management of adults and children with MDR- and XDR-TB with a particular emphasis on the utility of newer and repurposed drugs such as linezolid, bedaquiline and delamanid, as well as management of MDR- and XDR-TB in special situations such as in HIV-infected persons and in children.

IMPLICATIONS

This review informs on the prevention, diagnosis, and clinical management of MDR-TB and XDR-TB.

Managing tuberculosis infection in children in the USA: an update

The rate of tuberculosis (TB) disease has steadily declined in the last two decades in the USA, and over two-thirds of all cases now occur in foreign-born persons. Further declines in the incidence of TB will be most impacted by identifying and treating persons with TB infection. However, difficulties in accessing care, poor specificity of diagnostic tests and long courses of therapy historically have led to suboptimal screening of groups at high risk for infection, false-positive test results from cross-reaction with the bacille Calmette-Guérin vaccine and low treatment completion rates, respectively. This article reviews newer testing and treatment strategies for TB infection emphasizing risk and benefits of testing and treating.