This observational study aims to assess the effect of once-weekly s.c. semaglutide 2.4 mg as an adjunct to a calorie-reduced diet and increased physical activity on weight loss, change in hunger, body composition, depression, and quality of life after 68 weeks of treatment in adolescents diagnosed with monogenic obesity in routine clinical care.

The primary objective of this prospective, non-interventional observational study is to evaluate the effect of once-weekly s.c. semaglutide 2.4 mg in routine clinical care as an adjunct to a calorie-reduced diet and increased physical activity on weight loss after 68 weeks of treatment in adolescents diagnosed with monogenic obesity.

The secondary objectives of this prospective, non-interventional observation are to evaluate treatment compliance and to assess the influence of once-weekly s.c. semaglutide 2.4 mg in clinical practice on hunger score, body mass parameters, body composition, and depression score after 68 weeks of treatment in adolescents diagnosed with monogenic obesity. In addition, we will document the known parameters of safety and tolerability to determine safety and tolerability in clinical practice.

The exploratory objective of this prospective, non-interventional observation is to assess user satisfaction by measuring change in subjective hunger score, quality of life, and perceptions and attitudes regarding treatment with semaglutide in adolescents diagnosed with monogenic obesity treated in routine clinical practice with once-weekly s.c. semaglutide 2.4 mg after 68 weeks of treatment.

Inclusion Criteria:

1. Treatment with semaglutide as prescribed in routine clinical practice according to summary of product characteristics.
2. Informed consent of the patient, their parents, or legally acceptable representative (LAR) of participant and adolescent assent, as age-appropriate.
3. Age at time of signing informed consent: ≥12 to <21 years.
4. BMI ≥95th percentile as defined on sex- and age-specific BMI growth charts (CDC.gov)
5. Body weight of >60 kg.
6. Diagnosis of monogenic obesity by a Clinical Laboratory Improvement Amendments (CLIA)/ College of American Pathologists (CAP)/International Organisation for Standardization (ISO) 1518-certified laboratory using ACMG criteria as pathogenic (P), likely pathogenic (LP) and variant of uncertain significance (VUS).

Exclusion Criteria:

1. Participation in any interventional clinical trials at the time of enrolment.

2. Females of childbearing potential who are not using adequate contraceptive methods (as required by local law or practice)

3. Hypersensitivity to the active substance or to any of the excipients listed:

   • Disodium phosphate, dihydrate
   • Propylene glycol
   • Phenol
   • Hydrochloric acid (for pH adjustment)
   • Sodium hydroxide (for pH adjustment)
   • Water for injection

4. The safety and efficacy of Wegovy have not been investigated in patients:

   • treated with other products for weight management,
   • with type 1 diabetes,
   • with severe renal impairment (see section 4.2),
   • with severe hepatic impairment (see section 4.2),
   • with congestive heart failure New York Heart Association (NYHA) class IV. Use in these patients is not recommended

Patients aged ≥12 to <21 years diagnosed with monogenic obesity, who agreed on treatment with semaglutide, are eligible for study participation.

Due to participant confidentiality requirements under GDPR regulations, IPD will not be shared. The study design also limits data sharing at this stage