Abstract Disclosure: C. Huber: Employee; Self; Rhythm Pharmaceuticals, Inc.. Stock Owner; Self; Rhythm Pharmaceuticals, Inc. B. Sweeney: Consulting Fee; Self; Rhythm Pharmaceuticals, Inc., Novo Nordisk. Research Investigator; Self; Rhythm Pharmaceuticals, Inc.. Speaker; Self; Rhythm Pharmaceuticals, Inc. J. Pomeroy: Research Investigator; Self; Rhythm Pharmaceuticals, Inc. U. Mallya: Employee; Self; Rhythm Pharmaceuticals, Inc.. Stock Owner; Self; Rhythm Pharmaceuticals, Inc. S. Zhang: Other; Self; Employer received funding from Rhythm Pharmaceuticals, Inc. to support this research. M. Yang: Other; Self; Employer received funding from Rhythm Pharmaceuticals, Inc. to support this research. S. Malhotra: Employee; Self; Rhythm Pharmaceuticals, Inc.. Stock Owner; Self; Rhythm Pharmaceuticals, Inc. A.M. Haqq: Advisory Board Member; Self; Rhythm Pharmaceuticals, Inc., Novo Nordisk, Foundation for Prader-Willi Research USA. Grant Recipient; Self; Weston Family Microbiome Initiative and Canadian Institutes of Health Research. Background: Setmelanotide has demonstrated efficacy in clinical trials of patients with obesity due to rare melanocortin-4 receptor pathway diseases. Real-world evidence can provide a greater understanding of patient outcomes, such as hyperphagia and quality of life, in a clinical practice setting. Real-world Evidence of SeTmelanotide fOr Hyperphagia and ChRonic Weight ManagEment (RESTORE) is a prospective, observational, longitudinal study aimed at assessing patient- and caregiver-reported real-world effectiveness of setmelanotide among patients with Bardet-Biedl syndrome and proopiomelanocortin, proprotein convertase subtilisin/kexin type 1, or leptin receptor deficiency and their caregivers. Methods: Patients aged ≥6 years and caregivers aged ≥18 years who are able to respond to a survey in English and consented to the Rhythm Intune Program are eligible for the study. Patients must have been prescribed, but not yet initiated, setmelanotide, not have been previously treated with setmelanotide, and not have previously participated in or be currently enrolled in any clinical trial, including setmelanotide trials. Caregivers must be confirmed legal guardians of patients without prior exposure to setmelanotide, have cared for their patient for ≥6 months, and not be paid professional caregivers. Participants will complete secure online surveys at baseline (ie, before treatment) and at 6 posttreatment time points over a 1-year study period. Patient surveys collect information on hyperphagia-related signs and symptoms, medical history, treatment adherence, weight management programs and treatment, comorbidities/complications, comedications, disease impact on psychological well-being and health-related quality of life, treatment satisfaction, work/school/activity status, and patient global assessment. Caregiver surveys include assessments on psychological well-being, treatment satisfaction, and impact on activities of daily living, work status, and family dynamics. A subset of study patients will be invited to receive a wearable device (CentrePoint® Insight Watch) to assess activity and sleep patterns. Treatments and outcomes among patients will be described and compared with baseline for all post-treatment initiation assessment time points. Current status: RESTORE is the first study to assess the real-world effectiveness of setmelanotide, has been IRB approved, and is actively enrolling. Presentation: 6/3/2024