Global Regulatory and Public Health Initiatives to Advance Pediatric Drug Development for Rare Diseases.

The literature thoroughly describes the challenges of pediatric drug development for rare diseases. This includes (1) generating interest from sponsors, (2) small numbers of children affected by a particular disease, (3) difficulties with study design, (4) lack of definitive outcome measures and assessment tools, (5) the need for additional safeguards for children as a vulnerable population, and (6) logistical hurdles to completing trials, especially with the need for longer term follow-up to establish safety and efficacy. There has also been an increasing awareness of the need to engage patients and their families in drug development processes and to address inequities in access to pediatric clinical trials. The year 2020 ushered in yet another challenge-the COVID-19 pandemic. The pediatric drug development ecosystem continues to evolve to meet these challenges. This article will focus on several key factors including recent regulatory approaches and public health policies to facilitate pediatric rare disease drug development, emerging trends in product development (biologics, molecularly targeted therapies), innovations in trial design/endpoints and data collection, and current efforts to increase patient engagement and promote equity. Finally, lessons learned from COVID-19 about building adaptable pediatric rare disease drug development processes will be discussed.

Common Commentary on Paediatric Oncology Drug Development Published: Another Step in Optimising Global Regulatory Coordination of Paediatric Development Plans.

The European Medicines Agency and the US Food and Drug Administration recently published a common commentary document on paediatric oncology drug development, building on the call for simultaneous submissions of paediatric investigation plans and initial pediatric study plans. The objective of this document is to guide deliberations and permit focused discussions at the monthly paediatric cluster calls, allowing early regulatory coordination of global development plans. The differences in regulations related to timeline are not considered posing a barrier in that regard.

Pediatric drug regulation: International perspectives.

There was a time when the predominant approach to exposing children to new drugs was to protect children from research. This has evolved over the past several decades into protecting children through research. To encourage pediatric studies and approval of pediatric medicines, governments have provided financial incentives as well as obligations/requirements for pharmaceutical companies to carry out pediatric studies in certain circumstances. The unique considerations for children have been acknowledged by the various governments and drug regulatory agencies through international dialogue and cooperation among patient and patient care representatives, regulatory agencies, and academic, clinical and manufacturing stakeholders. We describe pediatric drug regulation in five of the largest international drug regulatory agencies and additionally discuss efforts at international cooperation and discussion in pediatric drug regulation.

Enrollment of Neonates in More Than One Clinical Trial.

Because the highest rates of morbidity and mortality in neonates are seen in those born at <32 weeks' gestation, this group has the most urgent need for novel therapies to improve survival and outcome. Legislative efforts in the United States and Europe have attempted to address this issue by requiring the study of drugs, biological and nutritional products, devices, and other therapies in this population through a combination of high-quality regulatory and clinical trials, quality improvement initiatives, and observational studies. Because there are relatively small numbers of very preterm neonates born each year in any 1 country or continent, and because a significant number of clinical trials are recruiting at any 1 time, a neonate may meet enrollment criteria for >1 clinical trial. Neonatal units that have the infrastructure and resources to engage in research frequently face the question of whether it is permissible to enroll a neonate in >1 trial. This article examines the pertinent scientific, ethical, regulatory, and industry issues that should be taken into account when considering enrolling neonates in multiple clinical studies.

Neonatal medicines research: challenges and opportunities.

INTRODUCTION: The key feature of the newborn is its fast age-dependent maturation, resulting in extensive variability in pharmacokinetics and -dynamics, further aggravated by newly emerging covariates like treatment modalities, environmental issues or pharmacogenetics. This makes clinical research in neonates relevant and needed, but also challenging. AREAS COVERED: To improve this knowledge, tailoring research tools as well as building research networks and clinical research skills for neonates are urgently needed. Tailoring of research tools is illustrated using the development of dried blood spot techniques and the introduction of micro-dosing and -tracer methodology in neonatal drug studies. Both techniques can be combined with sparse sampling techniques through population modeling. Building research networks and clinical research skills is illustrated by the initiatives of agencies to build and integrate knowledge on neonatal pharmacotherapy through dedicated working groups. EXPERT OPINION: Challenges relating to neonatal medicine research can largely be overcome. Tailored tools and legal initiatives, combined with clever trial design will result in more robust information on neonatal pharmacotherapy. This necessitates collaborative efforts between clinical researchers, sponsors, regulatory authorities, and last but not least patient representatives and society.

Applying Regulatory Science to Develop Safe and Effective Medicines for Neonates: Report of the US Food and Drug Administration First Annual Neonatal Scientific Workshop, October 28-29, 2014.

The First Annual Neonatal Scientific Workshop focused on the needs of the neonate by addressing the basic question: what information is required to inform decision making both at the regulatory level and at the bedside? Priority therapeutic areas include neonatal lung, brain, and gastrointestinal injury, retinopathy of prematurity, sepsis, and neonatal abstinence syndrome. Scientific progress in these therapeutic areas, regulatory standards, and the acceptable design and conduct of clinical trials must be aligned. This report will review potential approaches to enhancing neonatal drug development.

Slx9p facilitates efficient ITS1 processing of pre-rRNA in Saccharomyces cerevisiae.

Slx9p (Ygr081cp) is a nonessential yeast protein previously linked genetically with the DNA helicase Sgs1p. Here we report that Slx9p is involved in ribosome biogenesis in the yeast Saccharomyces cerevisiae. Deletion of SLX9 results in a mild growth defect and a reduction in the level of 18S rRNA. Co-immunoprecipitation experiments showed that Slx9p is associated with 35S, 23S, and 20S pre-rRNA, as well as U3 snoRNA and, thus, is a bona fide component of pre-ribosomes. The most striking effects on pre-rRNA processing resulting from deletion of SLX9 is the accumulation of the mutually exclusive 21S and 27SA2 pre-rRNA. Furthermore, deletion of SLX9 is synthetically lethal with mutations in Rrp5p that block cleavage at either site A2 or A3. We conclude that Slx9p has a unique role in the processing events responsible for separating the 66S and 43S pre-ribosomal particles. Interestingly, homologs of Slx9p were found only in other yeast species, indicating that the protein has been considerably less well conserved during evolution than the majority of trans-acting processing factors.

Saccharomyces cerevisiae Sof1p associates with 35S Pre-rRNA independent from U3 snoRNA and Rrp5p.

Sof1p is a trans-acting protein that is essential for biogenesis of the 40S ribosomal subunits in the yeast Saccharomyces cerevisiae. Because of its involvement in the early cleavage steps of precursor rRNA, its interaction with Nop1p and its ability to coprecipitate U3 snoRNA, Sof1p has so far been regarded as a protein that is specific to the U3 snoRNP. To determine whether a site exists within U3 snoRNA with which Sof1p directly or indirectly associates, we studied the ability of ProtA-tagged Sof1p to coimmunoprecipitate mutant versions of U3 snoRNA. None of the tested mutations had a significant effect on the recovery of mutant U3 from cell extracts. Further coimmunoprecipitation experiments, using cells that could be genetically depleted for either Sof1p or U3 snoRNA demonstrated that the two factors associate independently of each other with the 35S precursor RNA. Indeed, association between Sof1p and U3 snoRNA was abolished in cells in which 35S pre-rRNA transcription was blocked. Finally, we found that an overall reduction in the levels of box C/D snoRNPs by genetic depletion of the common Nop58p protein did not affect coprecipitation of 35S pre-rRNA by Sof1p. From these data, we conclude that Sof1p does not assemble into the 90S preribosome as part of the U3, or any other box C/D, snoRNP. The early and independently assembling trans-acting factor Rrp5p also proved to be dispensable for assembly of Sof1p.

U3 snoRNP and Rrp5p associate independently with Saccharomyces cerevisiae 35S pre-rRNA, but Rrp5p is essential for association of Rok1p.

Biogenesis of eukaryotic ribosomal subunits proceeds via a series of precursor ribonucleoprotein particles that correspond to different stages in the maturation pathway. The different pre-ribosomal particles each contain a distinct complement of non-ribosomal, trans-acting factors that are crucial for correct and efficient progress of the maturation process. Although in recent years we have gained considerable insight into the composition of the pre-ribosomal particles, our knowledge how the ordered association with and their dissociation from the pre-ribosome of these trans-acting factors is controlled is still quite limited. Here, we have studied the mutual dependence between three of these factors, Rrp5p, U3 snoRNP and Rok1p, all essential for the early stages of pre-rRNA processing/assembly, for association with the 35S pre-rRNA in Saccharomyces cerevisiae. Using co-immunoprecipitation assays, we show that Rrp5p and U3 snoRNP associate independently of each other and that the two factors do not detectably interact prior to incorporation into the pre-ribosome. In contrast, association of the putative RNA helicase Rok1p, which is known to genetically interact with Rrp5p, is absolutely dependent on the presence of the latter protein but does not require U3.