Catalysing the development and introduction of paediatric drug formulations for children living with HIV: a new global collaborative framework for action

Public health relevance of medicines developed under paediatric legislation in Europe and the USA: a systematic mapping study

BACKGROUND

Legislation in the European Union (EU) and the USA promoting the development of paediatric medicines has contributed to new treatments for children. This study explores how such legislation responds to paediatric health needs in different country settings and globally, and whether it should be considered for wider implementation.

METHODS

We searched EU and US regulatory databases for medicines with approved indications resulting from completed paediatric development between 2007 and 2018. Of 195 medicines identified, 187 could be systematically mapped to the burden of the target disease for six study countries (Australia, Brazil, Canada, Kenya, Russia, South Africa) and globally, using disability-adjusted life years (DALYs). All medicines were also screened for inclusion on the WHO Model List of Essential Medicines (EML) and the EML for children under 13 years (EMLc).

RESULTS

The studied medicines were disproportionately focused on non-communicable diseases, which represented 68% of medicines and 21% of global paediatric DALYs. On the other hand, we found 28% of medicines for communicable, maternal, neonatal and nutritional disorders, representing 73% of global paediatric DALYs. Neonatal disorders and malaria were mapped with two medicines, tuberculosis and neglected tropical diseases with none. The gap between medicines and paediatric DALYs was greater in countries with lower income. Still, 34% of medicines are included in the EMLc and 48% in the EML.

CONCLUSIONS

Paediatric policies in the EU and the USA are only partially responsive to paediatric health needs. To be considered for wider implementation, paediatric incentives and obligations should be more targeted towards paediatric health needs. International harmonisation of legislation and alignment with global research priorities could further strengthen its impact on child health and support ongoing efforts to improve access to medicines. Furthermore, efforts should be made to ensure global access to authorised paediatric medicines.

Assessing user preferences for design characteristics of oral dissolvable strips for pediatric HIV medication: a qualitative study

BACKGROUND

Current infant antiretroviral therapy formulations pose barriers to daily adherence due to complex weight-based dosing, conspicuous preparation, and poor palatability. These adherence barriers jeopardize adherence, making patients vulnerable to virologic failure, development of drug resistance, and preventable mortality. Our team has previously established proof-of-principle for multi-drug oral dissolvable strips as alternative pediatric antiretroviral formulations with the potential to overcome these challenges and improve pediatric ART adherence and outcomes. The objective of this study was to assess caregiver and provider preferences for oral dissolvable strips and its packaging to inform its development.

METHODS

Guided by concepts of user-centered design, we conducted key informant interviews with 30 HIV care providers and focus group discussions targeting caregivers of children < 10 years of age living with HIV at 3 Kenyan hospitals. Key informant interviews and focus group discussions were audio recorded, translated/transcribed verbatim, and hand coded for a-priori and emergent themes.

RESULTS

A total of 30 providers and 72 caregivers (caring for 83 children, aged 5 months to 18 years) participated in the study. Caregivers and providers expressed a strong desire for an easier way to administer medication, especially among children too young to swallow tablets whole, and expressed enthusiasm around the idea of oral dissolvable strips. Key preferences included a pleasant taste; one strip per dose; small size with rapid dissolution; clear markings and instructions; and no special storage requirements. For packaging, stakeholders preferred individually wrapped strips within a dispenser. The individual packaging should be durable, waterproof, and easy to dispose of in communal spaces. They should also be easy to open, with clear indications where to open. The packaging holding the strips should be durable, re-usable, accommodating of various refill frequencies, and easy to use for children as young as 6.

DISCUSSION

The concept of oral dissolvable strips was highly acceptable to caregivers of children living with HIV and HIV care providers. By engaging stakeholders in an iterative design process starting from the early phases of design and development, we will maximize the likelihood of developing a product that is acceptable to the caregiver and infant, therefore leading to sustainable adherence.

Effectiveness and safety of tenofovir alafenamide in children and adolescents living with HIV: a systematic review

INTRODUCTION

Tenofovir alafenamide (TAF) is approved for paediatric use in fixed-dose combination tablets, but efficacy and safety data in children are limited. We conducted a systematic review on the efficacy/effectiveness and safety of TAF in infants, children and adolescents living with HIV.

METHODS

We searched MEDLINE, Embase, the Cochrane Library, clinical trial registries, reference lists and relevant conferences to identify literature published January 2009-March 2021. We included clinical trials and observational studies assessing the efficacy/effectiveness or safety of TAF through ≥6 months of treatment in participants aged 0-19 years.

RESULTS AND DISCUSSION

Overall 3626 abstracts and 371 full papers were screened. Four single-arm, innovator-funded trials (341 participants) and a pooled analysis of those trials were identified. All four trials included treatment-experienced and virally suppressed children or adolescents. One trial also included treatment-naïve adolescents with baseline viral load >1000 copies/ml. The risk of bias was rated as low in one study and unclear in the other three owing to missing data on study design (all conference presentations). At 48 weeks, 92% (46/50) of treatment-naïve participants were virally suppressed (one trial). Among treatment-experienced participants with viral load at 48 weeks, 214 of 224 participants were virally suppressed. Across the studies, one grade 3/4 adverse event was considered drug-related (intermediate uveitis). There were three discontinuations for adverse events (grade 2 anxiety and insomnia, grade 1 iridocyclitis [drug-related] and grade 1 pulmonary tuberculosis [unrelated to treatment]). One accidental death occurred across the four studies. In the pooled analysis of 223 participants, the median change in bone mineral density z-score (height- and age-adjusted) from baseline to 48 weeks was -0.12 (interquartile range [IQR] -0.46, 0.17) to 0.05 (IQR not reported) for spine, and -0.09 (IQR -0.33, 0.07) to 0.09 (IQR not reported) for total body less head. Weight-for-age z-scores increased by 0.25 from baseline to 48 weeks.

CONCLUSIONS

Four single-arm trials were identified in this systematic review, with initial evidence suggesting good viral suppression and no obvious safety concerns in children and adolescents on TAF-containing regimens over 24-48 weeks. However, further comparative and longer-term safety data are needed in children and adolescents, including on weight and metabolic changes.

Potential of Long-Acting Products to Transform the Treatment and Prevention of Human Immunodeficiency Virus (HIV) in Infants, Children, and Adolescents

Long-acting antiretroviral products have the potential to transform human immunodeficiency virus (HIV) prevention and treatment approaches in pediatric populations. Broadly neutralizing antibodies and/or long-acting antiretroviral formulations by injection could dramatically improve provision of HIV prophylaxis and/or early treatment to newborns and infants at risk of HIV infection. Challenges in daily oral antiretroviral administration to toddlers and school age children living with HIV may be relieved by use of long-acting formulations, but the pharmacokinetics and safety of these products in children must be studied before they can enter routine clinical use. Although some initial studies of broadly neutralizing antibodies and injectable long-acting agents in infants and young children are underway, more studies of these and other long-acting products are needed. For many adolescents, compliance with daily medication administration is especially challenging. Long-acting products hold particular promise for adolescents living with HIV as well as those at high risk of HIV acquisition, and adolescents can usually be included in the drug development pipeline simultaneously with adults. Long-acting products have the potential to provide alternatives to lifelong daily oral drug administration across the pediatric age spectrum, leading to more effective prevention and treatment of HIV infection in infants, children, and adolescents.

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.

Simplified dolutegravir dosing for children with HIV weighing 20 kg or more: pharmacokinetic and safety substudies of the multicentre, randomised ODYSSEY trial

BACKGROUND

Paediatric dolutegravir doses approved by stringent regulatory authorities (SRAs) for children weighing 20 kg to less than 40 kg until recently required 25 mg and 10 mg film-coated tablets. These tablets are not readily available in low-resource settings where the burden of HIV is highest. We did nested pharmacokinetic substudies in patients enrolled in the ODYSSEY-trial to evaluate simplified dosing in children with HIV.

METHODS

We did pharmacokinetic and safety substudies within the open-label, multicentre, randomised ODYSSEY trial (NCT02259127) of children with HIV starting treatment in four research centres in Uganda and Zimbabwe. Eligible children were randomised to dolutegravir in ODYSSEY and weighed 20 kg to less than 40 kg. In children weighing 20 kg to less than 25 kg, we assessed dolutegravir's pharmacokinetics in children given once daily 25 mg film-coated tablets (approved by the SRAs at the time of the study) in part one of the study, and 50 mg film-coated tablets (adult dose) or 30 mg dispersible tablets in part two of the study. In children weighing 25 kg to less than 40 kg, we also assessed dolutegravir pharmacokinetics within-subject on film-coated tablet doses of 25 mg or 35 mg once daily, which were approved by the SRAs for the children's weight band; then switched to 50 mg film-coated tablets once daily. Steady-state 24 h dolutegravir plasma concentration-time pharmacokinetic profiling was done in all enrolled children at baseline and 1, 2, 3, 4, 6, and 24 h after observed dolutegravir intake. Target dolutegravir trough concentrations (C_trough) were based on reference adult pharmacokinetic data and safety was evaluated in all children in the corresponding weight bands who consented to pharmacokinetic studies and received the studied doses.

FINDINGS

Between Sept 22, 2016, and May 31, 2018, we enrolled 62 black-African children aged from 6 years to younger than 18 years (84 pharmacokinetic-profiles). In children weighing 20 kg to less than 25 kg taking 25 mg film-coated tablets, the geometric mean (GM) C_trough (coefficient of variation) was 0·32 mg/L (94%), which was 61% lower than the GM C_trough of 0·83 mg/L (26%) in fasted adults on dolutegravir 50 mg once-daily; in children weighing 25 kg to less than 30 kg taking 25 mg film-coated tablets, the GM C_trough was 0·39 mg/L (48%), which was 54% lower than the GM C_trough in fasted adults; and in those 30 kg to less than 40 kg taking 35 mg film-coated tablets the GM C_trough was 0·46 mg/L (63%), which was 45% lower than the GM C_trough in fasted adults. On 50 mg film-coated tablets or 30 mg dispersible tablets, C_trough was close to the adult reference (with similar estimates on the two formulations in children in the 20 to <25 kg weight band), with total exposure (area under the concentration-time curve from 0 h to 24 h) in between reference values in adults dosed once and twice daily, where safety data are reassuring, although maximum concentrations were higher in children weighing 20 kg to less than 25 kg than in the twice-daily adult reference. Over a 24-week follow-up period in 47 children on 30 mg dispersible tablets or 50 mg film-coated tablets, none of the three reported adverse events (cryptococcal meningitis, asymptomatic anaemia, and asymptomatic neutropenia) were considered related to dolutegravir.

INTERPRETATION

Adult dolutegravir 50 mg film-coated tablets given once daily provide appropriate pharmacokinetic profiles in children weighing 20 kg or more, with no safety signal, allowing simplified practical dosing and rapid access to dolutegravir. These results informed the WHO 2019 dolutegravir paediatric dosing guidelines and have led to US Food and Drug Administration approval of adult dosing down to 20 kg.

FUNDING

Paediatric European Network for Treatment of AIDS Foundation, ViiV Healthcare, UK Medical Research Council.

Hepatitis C Virus Treatment in Children: A Challenge for Hepatitis C Virus Elimination

Hepatitis C is a global public health threat. The introduction of direct-acting antivirals (DAAs) brings the prospect of curing the 71 million people living with the disease, dramatically changing the landscape of hepatitis C. The World Health Organization developed a roadmap for the elimination and cure of hepatitis C by 2030 with a clear goal with measurable targets. However, there is a lack of a well-defined strategy to tackle the hepatitis C virus (HCV) problem in children and adolescents vis-à-vis the adult population. Hepatitis C in children and adolescents can be addressed as part of a national policy for elimination in the whole population, namely macroelimination, or could be fragmented into a microelimination approach targeting the high-risk population groups. Children born to HCV-infected mothers, adolescents who are injecting drugs, migrants, and those suffering from inherited blood diseases are important target populations. After the U.S. Food and Drug Administration approval for the use of DAAs in children aged 3 years and above, evidence from clinical trials and real-world experience was accumulated using brand and generic medicines, with sustained virological response rates exceeding 95%. The evidence created should guide policies on the management of hepatitis C in children and adolescents. There are many challenges in managing HCV in this left-behind marginalized population. The lack of awareness and epidemiological data, consent age, prohibitive prices of medicines, and absence of policies on access to diagnostics, treatment, and linkage to care are among the many barriers to service delivery that should be addressed to achieve the elimination goal by 2030.

Prioritising the most needed paediatric antiretroviral formulations: the PADO4 list

Despite considerable progress in paediatric HIV treatment and timely revision of global policies recommending the use of more effective and tolerable antiretroviral regimens, optimal antiretroviral formulations for infants, children, and adolescents remain limited. The Paediatric Antiretroviral Drug Optimization group reviews medium-term and long-term priorities for antiretroviral drug development to guide industry and other stakeholders on formulations most needed for low-income and middle-income countries. The group convened in December, 2018, to assess progress since the previous meeting and update the list of priority formulations. Issues relating to drug optimisation for neonatal prophylaxis and paediatric treatment, and those relating to the investigation of novel antiretrovirals in adolescents and pregnant and lactating women were also discussed. Continued focus on identifying, prioritising, and providing access to optimal antiretroviral formulations suitable for infants, children, and adolescents is key to ensuring that global HIV treatment targets can be met.

Hepatitis C virus infection in children and adolescents

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and associated morbidity and mortality worldwide. Short-course, oral, curative, direct-acting antiviral regimens have transformed treatment for HCV infection. Since the 2016 launch of the first global strategy towards elimination of viral hepatitis as a public health threat by 2030, the predominant focus of the global response has been on the treatment of adults, who bear the greatest burden of morbidity and mortality of HCV-related chronic liver disease. Compared with adults, there has been little attention paid to addressing the response to HCV in children and adolescents, in part because of the scarcity of data to inform specific paediatric management practices and policy. In this Series paper, we summarise knowledge on the epidemiology, natural history, and treatment of chronic HCV infection in adolescents and children, and we highlight key differences from infection acquired in adulthood. The estimated global prevalence and burden of HCV infection in children aged 1-19 years is 0·15%, corresponding to 3·5 million people (95% CI 3·1-3·9 million). HCV infection is usually asymptomatic during childhood, and cirrhosis and hepatocellular carcinoma are rare. Sofosbuvir with ledipasvir and sofosbuvir with ribavirin have received regulatory approval and guidelines recommend their use in adolescents aged 12 years and older with HCV infection. In April, 2019, glecaprevir with pibrentasvir also received regulatory approval for adolescents aged 12-17 years. Key actions to address the current policy gaps and achieve treatment scale-up that is comparable to that in adults include: establishment of a campaign on access to testing and treatment that is targeted at children and adolescents; fast-track evaluation of pan-genotypic regimens; and accelerated approval of paediatric formulations. Research gaps that need to be addressed include: age-specific prevalence studies of HCV viraemia in priority countries; further validation of non-invasive tests for staging of liver disease in children; and establishment of paediatric treatment registries and international consortia to promote collaborative research agendas.