17 Clinical Trials

Paediatric clinical trials are among the most challenging studies to conduct in drug development.

Researchers must generate robust safety, efficacy and biomarker data while working within strict physiological, ethical and operational constraints. Unlike adults, children have limited circulating blood volume, rapidly changing physiology and heightened sensitivity to invasive procedures.

As a result, trial designs that rely on conventional adult sampling approaches are often impractical in paediatric populations. These realities are driving a shift towards laboratory strategies designed around the needs of children rather than adapted from adult research.

Blood collection remains one of the most significant challenges. A sample volume that appears modest in an adult can represent a meaningful proportion of total blood volume in a neonate or young child. Regulatory guidance in the United States and Europe emphasises minimising blood collection and carefully managing cumulative blood loss during research participation.

In Europe, research-related blood loss is generally recommended not to exceed 1% of total blood volume at a single time point and 3% over four weeks. These restrictions require clinical teams to maximise the scientific value obtained from every specimen collected.

Increasingly, central laboratories are becoming involved much earlier in protocol development to address these constraints. Rather than serving solely as testing providers, laboratory experts can evaluate blood-volume requirements, model cumulative sampling burdens across study visits and assess whether planned analyses are truly necessary.

Early collaboration allows study teams to optimise sampling schedules, reduce unnecessary testing and identify feasibility risks before a protocol is finalised. This is particularly important in paediatric programmes, where operational challenges can quickly become participant burdens.

Innovation

Technological innovation is also expanding what is possible in paediatric research. Low-volume collection tubes, qualified for a range of laboratory tests, enable investigators to obtain required data using substantially smaller blood draws than traditional approaches.

Advances in microsampling have created additional opportunities. Capillary collection technologies and other minimally invasive sampling approaches may reduce reliance on venepuncture, potentially improving participant experience while supporting studies that require frequent monitoring.

These methods also offer potential advantages for decentralised and remote trial models, although analytical validation remains essential to confirm suitability for specific assays and study endpoints.

However, reducing collection volume is only part of the solution. Equally important is ensuring that each sample yields the maximum possible information. Sample-sparing laboratory workflows are therefore becoming increasingly valuable.

Strategies such as reflex testing, assay miniaturisation, platform consolidation and analyte prioritisation can help reduce sample consumption while maintaining analytical integrity. Preventing sample loss is also critical.

In paediatric studies, redraws resulting from haemolysis, clotting, processing errors or insufficient volume can create additional burden for participants and caregivers while jeopardising protocol compliance and data completeness. Robust collection, handling and quality-management procedures help minimise these risks.

As global paediatric trials become more complex, harmonised laboratory processes are gaining importance. Validating assays across multiple regions and reducing the need for sample splitting or intercontinental shipment can help preserve limited specimen volumes while maintaining consistency of results.

Looking ahead, digital planning tools and protocol-modelling technologies may further enhance trial feasibility by helping teams predict blood-volume requirements and evaluate alternative sampling strategies before studies begin.

Ultimately, successful paediatric trials depend on more than innovative technologies alone. They require integrated planning that balances scientific objectives with the realities of conducting research in children.

By combining thoughtful protocol design, low-volume sampling technologies, sample-conserving workflows and harmonised analytical processes, the clinical research community is finding new ways to generate high-quality data while reducing burden on young participants and their families. In paediatric research, every drop truly counts.

Every drop counts