The GAPP Study
The GAPP Study is a multicentre, non-profit Phase III clinical trial sponsored by TEDDY Network to evaluate the efficacy, safety, and pharmacokinetics of a paediatric liquid formulation of gabapentin for chronic moderate to severe neuropathic, nociplastic, or mixed pain in children and adolescents.
By generating clinical evidence in patients aged 3 months to under 18 years, the study aims to support safer and more appropriate use of gabapentin in paediatric chronic pain management.
Study Objectives
The primary objective of the study is to evaluate the effectiveness of gabapentin in reducing chronic pain intensity in paediatric patients. Secondary objectives include:
Assessing the safety and tolerability of gabapentin in children and adolescents.
Characterising the pharmacokinetic profile of gabapentin across different paediatric age groups.
Evaluating the impact of treatment on quality of life, sleep and daily functioning.
Assessing treatment acceptability and overall patient and caregiver satisfaction.
Study Design
GAPP is a multicentre, single-arm, adaptive, prospective cohort study involving children and adolescents aged between 3 months and less than 18 years with chronic neuropathic, nociplastic or mixed pain.
The study incorporates an adaptive design with a planned interim analysis. This innovative approach allows the study to reassess assumptions during its conduct, helping to optimise sample size requirements and minimise unnecessary burden on participants while maintaining scientific rigour.
Why is this Study Important?
There is currently a major unmet need for evidence-based treatments for chronic pain in children. With a more specific one that could highlight better the high unmet medical need, for example:
Neuropathic pain is not an approved indication for gabapentin in the paediatric population despite its widespread clinical use.
Age-appropriate formulations are often unavailable, leading to challenges in dosing accuracy and treatment adherence.
Drug exposure and response may vary substantially across paediatric age groups, particularly in younger children, making dedicated pharmacokinetic studies essential.
The importance of these research questions has been recognised by the European Medicines Agency (EMA), which included gabapentin in its Priority List for Studies into Off- Patent Paediatric Medicinal Products Used Off-Label.
The results of the GAPP Study are expected to contribute to improved clinical decision- making, more evidence-based prescribing practices, and ultimately better care for children and adolescents living with chronic pain.
Patient and Family Involvement
A key feature of the GAPP Study is the active involvement of patients and families throughout the research process. Through a dedicated Patient Advisory Board (PAB), young people with lived experience of chronic pain, caregivers and patient representatives contribute to study design, conduct and dissemination activities, ensuring that patient perspectives remain central to the project.
The PAB brings together 17 members representing several Young Persons Advisory Groups (YPAGs) and patient organisations across Europe. Through their diverse experiences and expertise, PAB members provide valuable insights that help shape a patient-centred approach to the study.
The PAB has been established within the TEDDY KIDS Network and includes representatives from:
ADEE (Asociación de Displasia Ectodérmica de España) ↗
AEV ODV (Associazione Estrofia Vescicale Epispadia) Italy ↗
ANDO (Associação Nacional de Displasias Ósseas) Portugal ↗
eyeYPAG (Young Persons Advisory Group for Eye Diseases) United Kingdom ↗
KIDS (Kids Impacting DIseases through Science) Albania ↗
KIDS (Kids Impacting DIseases through Science) Bari, Italy ↗
KIDS (Kids Impacting DIseases through Science) Kosova ↗
KIDS (Kids Impacting DIseases through Science) Rare Hella, Greece ↗
KIDS (Kids Impacting DIseases through Science) Umbria, Italy ↗
POLPEDNET KIDS (Kids Impacting DIseases through Science) Warsaw ↗
Role of the Patient Advisory Board (PAB)
The PAB plays an advisory role throughout the GAPP study by:
Providing the perspectives of young people, patients, and caregivers to support patient-centred research.
Advising on study materials, participant information, and communication to improve clarity and accessibility.
Sharing feedback on the participant experience and the feasibility of study procedures.
Identifying the needs, expectations, and priorities of patients and families throughout the study.
Supporting the development of inclusive and patient-oriented strategies across all stages of the project.
Contributing recommendations to the Study Steering Committee (SSC) through the PAB representative, where relevant to study conduct and governance.
Promoting meaningful patient and family involvement in research while respecting study confidentiality and governance requirements.