Background Given the poor prognoses and potential treatment toxicities faced by pediatric patients in early-phase oncology trials, evaluating quality of life (QoL) is crucial for both families and physicians when considering patient recruitment. This prospective, longitudinal study evaluates the impact of trial participation on QoL in children, agreement between self-reports, proxy-reports, and physician assessments, and associations with demographic and clinical factors. Procedure Patients aged 5–18 years enrolled in phase I/II clinical trials at Hospital Niño Jesus from 2019 to 2023 and their caregiver proxies were eligible. PedsQL 3.0 Cancer Module was independently completed by children and proxies at baseline, day +30, and day +90 of cycle 1 day 1. Stratified analyses by gender, age, tumor type, outcome, reason of end of treatment, and trial characteristics were performed. Agreement between child, proxy, and investigator responses was measured. Results Ninety-three pediatric patients with cancer and their proxies were included. The 38.71% of patients and 33.33% of proxies experienced a clinically relevant change in QoL scores after 30 days. Patients in phase II trials demonstrated greater QoL improvements compared to phase I (p = 0.0061). No significant associations were found between improvement of QoL and demographic or clinical factors. Proxies consistently reported lower QoL scores than patients, while physicians underestimated symptom severity compared to patient-reported outcomes. Conclusions Trial participation aligns with maintaining or improving QoL, particularly in later-phase trials. Discrepancies among patient, proxy, and investigator perspectives underscore the necessity of multi-informant tools to capture comprehensive insights.

Objectives. Neuroblastoma is the most common extracranial tumour in children, and prognosis for refractory and relapsed disease is still poor. Early Phase clinical trials play a pivotal role in the development of novel drugs. Ensuring adequate recruitment is crucial. The primary aim was to determine the rate of participation trials for children with refractory/relapsed neuroblastoma in two of the largest Drug Development European institutions. Methods. Data from patients diagnosed with refractory/relapsed neuroblastoma between January 2012 and December 2018 at the two institutions were collected and analysed. Results. Overall, 48 patients were included. A total of 31 (65%) refractory/relapsed cases were enrolled in early Phase trials. The main reasons for not participating in clinical trials included: not fulfilling eligibility criteria prior to consent (12/17, 70%) and screening failure (2/17, 12%). Median time on trial was 4.3 months (range 0.6-13.4). Most common cause for trial discontinuation was disease progression (67.7%). Median overall survival was longer in refractory (28 months, 95% CI, 20.9-40.2) than in relapsed patients (14 months, 95% CI, 8.1-20.1)) [p=0,034]. Conclusions. Although two thirds of children with refractory/relapsed neuroblastoma were enrolled in early Phase trials, recruitment rates can still be improved. The main cause for not participating on trials was not fulfilling eligibility criteria prior to consent, mainly due to performance status and short life expectancy. This study highlights the hurdles to access to innovative therapies for children with relapsed/refractory neuroblastomas and identifies key areas of development to improve recruitment to early phase trials.