1102P - Efficacy endpoints studied in clinical trials for early-onset leukaemia

Abstract

BackgroundAcute lymphoblastic leukaemia (ALL) is associated with high survival rates in paediatrics and young adults and less favourable outcomes in older adults. Clinical trials (CTs) studying survival-based endpoints in ALL lead to significantly prolonged trial durations, resulting in delays to medicines access. Biomarkers in ALL have been correlated with longer-term outcomes, potentially accelerating the clinical development of novel treatments. The aim of this study was to characterise efficacy measures investigated in ALL CTs conducted in the European Union (EU)/Economic Area (EEA). MethodsInterventional Phase II to Phase IV ALL CTs registered in the EU Clinical Trials Register over an 11-year period (2007-2017) were identified. Therapeutic CTs reporting efficacy data in the English language for investigational medicinal products of chemical, biological and biotechnological origin were included in the study. A protocol design or age filter was not applied to avoid limiting the scope of outcomes identified. Primary and secondary efficacy endpoints were extracted from the selected CTs and categorised according to type of measurement. A data mining process was performed to detect trends in outcomes studied. ResultsThe data set comprised 68 CTs representing about 20,000 patients. The majority of trials (69%, n=47) recruited patients from the adult population (18-64 years) and conducted only Phase II studies (62%, n=42). Twenty-three unique efficacy endpoints were identified and stratified into the clusters of survival (n=4), time-to-event (n=3), response rates and biomarkers (n=11) and other (n=5). Fifty-three per cent (n=36) of the trials reported 4-10 outcomes, with a mean of 4 outcomes per CT (range 1-10). The principal endpoints evaluated in CTs consisted of overall survival (CTs: 63%, n=43), minimal residual disease (CTs: 50%, n=34), event-free survival (CTs: 40%, n=27) and disease-free survival (CTs: 40%, n=27). ConclusionsThe high uptake of minimal residual disease as an efficacy parameter in ALL CTs is in line with reported findings confirming the prognostic value of this marker on clinical outcomes. Heterogeneity in the selection of efficacy endpoints was observed which warrants future work on the standardisation of efficacy outcomes in ALL CTs. Editorial acknowledgementThe Malta Medicines Authority. The Department of Pharmacy, Faculty of Medicine and Surgery, University of Malta. Legal entity responsible for the studyDepartment of Pharmacy, Faculty of Medicine and Surgery, University of Malta. FundingGovernment of Malta, Endeavour Scholarship Scheme 2017. DisclosureAll authors have declared no conflicts of interest.