TailorED: A Sequential Multiple Assignment Randomised Trial (SMART) of personalised treatment for Bulimia Nervosa and Binge Eating Disorder

Background: Bulimia Nervosa (BN) and Binge Eating Disorder (BED) are common and debilitating eating disorders. Although Cognitive Behavioural Therapy (CBT) is the gold standard treatment, many individuals do not respond to first-line interventions. This trial responds to the need for adaptive, individualised care strategies that optimise outcomes for non-rapid responders (NRRs). Methods: The TailorED Trial is a multi-centre Sequential Multiple Assignment Randomised Trial (SMART) enrolling 204 participants aged 16–60 with BN or BED. All participants commence with a guided digital CBT program (BEeT(GSH)). Rapid responders (≥70% reduction in binge episodes at 4 weeks) are randomised to either continue BEeT(GSH) or step down to a light-contact version (BEeT(LC)). NRRs are randomised to one of three arms: extended BEeTGSH, personalised psychotherapy package, or repetitive transcranial magnetic stimulation (rTMS). Data will be analysed using weighted linear regression within an intention-to-treat framework. Discussion: By evaluating personalised interventions in a SMART framework, this study aims to improve treatment matching for individuals who do not benefit from standard CBT. The trial integrates neurobiological, cognitive, and behavioural data to guide treatment decisions. Results will contribute critical insights into adaptive care pathways and the utility of novel modalities such as rTMS in treating binge-spectrum eating disorders. This protocol is to be used in conjunction with protocol X24-0167, “Gaining a Holistic Understanding of Eating Disorders: Phenotyping and Genotyping Illness”.