Systematic review of adoption, reporting and impact of health-related quality of life in phase III non-inferiority trials of systemic oncology treatments.

Background: Quality of life (QoL) assessment and patient-reported outcomes appear to be crucial in the rationale and interpretation of non-inferiority (NI) trials. The aim of this study was to assess the inclusion of QoL among endpoints in phase III NI oncology trials and the relevance of QoL results in the reporting and interpretation of these studies.

Materials And Methods: By PubMed search and hand-search of 11 selected journals, we identified phase III NI trials in adult patients affected by solid tumours, published between 2012 and 2021. Trials were classified according to 4 NI strategies: (1) different drugs; (2) alternative drug administration routes; (3) shorter treatment duration; (4) "deintensification" of treatment schedule. Three main endpoints were: (1) the proportion of publications including QoL among endpoints; (2) the proportion of primary publications reporting QoL results; (3) the proportion of trials with available QoL results actually favoring the experimental treatment out of trials declaring NI.

Results: 106 publications were eligible. QoL was included among endpoints in 59 studies (55.7%), and QoL results were available in 40 primary publications (37.7%). In the 73 trials testing the NI of different drugs, QoL was included in 43 trials (58.9%) and QoL results were present in 31 publications (42.5%). Among the 74 trials formally demonstrating NI, only 19 trials (25.7%) had QoL results actually supporting the experimental treatment.

Conclusions: In many NI trials in oncology, assessment and reporting of QoL are deficient. Furthermore, most trials formally claiming NI cannot count on QoL results actually supporting the experimental arm.