Despite a number of initiatives by regulators and legislators to provide incentives for clinical trials targeting the paediatric population, the volume of studies enrolling children remains far lower than for adults, and with a narrower research scope, researchers from Duke University in the US have found.

The analysis was conducted as part of the Clinical Trials Transformation Initiative, a public-private partnership set up by the US Food and Drug Administration and Duke University to identify practices that improve the quality and efficiency of clinical trials. Findings were reported online in the journal Pediatrics.

The Duke University researchers looked at more than 60,000 trials carried out between 2005 and 2010, using data entered into the US-based online registry Just over 5,000 of these studies were specifically designed to enrol participants under the age of 18 years.

Lag factors

According to lead author Dr Sara Pasquali, now co-director of the Michigan Congenital Heart Outcomes Research and Discovery Program at the University of Michigan, a number of factors are likely to play into this enrolment lag.

They include the rarity and diversity of many paediatric diseases; lack of paediatric research infrastructure; ethical issues associated with testing drugs on children; and difficulty in establishing appropriate endpoints or outcomes for investigational therapies in the paediatric population.

The relatively low occurrence of many paediatric diseases means “it can take much more time to build a research infrastructure, often involving multiple hospitals, to enrol enough patients in a study”, Pasquali noted.

“But with fewer studies to guide therapeutic decisions, treatments and outcomes for young patients often vary widely from centre to centre.”

Small trials

The Duke University researchers also found that enrolment numbers tended to be small in clinical studies conducted with children, making it difficult to obtain clinically meaningful information that could be generalised across larger populations.

Resources might be better expended on larger trials designed to answer the most pressing questions in paediatric research, rather than on numerous small trials, they suggested.

Among the most common fields of research for the paediatric trials included in the Duke University analysis were infectious diseases/vaccine studies (23%) and psychiatric/mental health studies (13%).

“For the vast majority of therapies used on children every day in the United States and around the world, clinicians lack basic data to support decisions about the correct dosage, the best type of medication to use, and the appropriate situations to provide treatment,” Pasquali commented.