Real-life Evaluation of WEGOVY (Semaglutide) Treatment in Adults With Monogenic Obesity (ObGeSema)

Rare genetic forms of obesity, so called monogenic obesity are linked to alteration in energy balance involving hypothalamic pathways.

More than 60 genes encoding for proteins located in the hypothalamic leptin/melanocortin pathway have been described in the French National Protocol for Diagnostic and Care (PNDS).

The natural history of monogenic obesity is characterized by an early onset in childhood, with a major increase in weight in adolescence and young adulthood. The worsening of obesity exposes these patients to severe complications.

Severe obesity and eating disorders have a major impact on the quality of life of the person but also of the family and caregivers. Clinical management is complex and requires comprehensive, specialized and multidisciplinary management. But the usual lifestyle approaches have so far shown disappointing results, similarly to bariatric surgery which leads to a more frequent weight regain in the situation of monogenic obesity, justifying new approaches.

In this context, evaluating the response to treatment in the particular condition of monogenic obesity is crucial to propose therapeutic options as early as possible to limit weight evolution and its complications.

GLP-1 (glucagon-like peptide 1) based innovative therapies have recently emerged as a promising option for treatment of obesity and its complications. This is the case for Semaglutide 2.4mg/week (WEGOVY®), developed by Novo Nordisk. However, there is a lack of data to confirm that semaglutide could be also effective in monogenic obesity.

The hypothesis in this study is that treatment with Semaglutide 2.4mg/week (WEGOVY®) could be as effective in monogenic obesities as in common obesity.

Rare genetic forms of obesity, so called monogenic obesity are linked to alteration in energy balance involving hypothalamic pathways. More than 60 genes encoding for proteins located in the hypothalamic leptin/melanocortin pathway have been described in the French National Protocol for Diagnostic and Care (PNDS).

The natural history of monogenic obesity is characterized by an early onset in childhood, with a major increase in weight in adolescence and young adulthood. The worsening of obesity exposes these patients to severe complications. Severe obesity and eating disorders have a major impact on the quality of life of the person but also of the family and caregivers. Clinical management is complex and requires comprehensive, specialized and multidisciplinary management. But the usual lifestyle approaches have so far shown disappointing results, similarly to bariatric surgery which leads to a more frequent weight regain in the situation of monogenic obesity, justifying new approaches.

In this context, evaluating the response to treatment in the particular condition of monogenic obesity is crucial to propose therapeutic options as early as possible to limit weight evolution and its complications.

GLP-1 (glucagon-like peptide 1) based innovative therapies have recently emerged as a promising option for treatment of obesity and its complications. This is the case for Semaglutide 2.4mg/week (WEGOVY®), developed by Novo Nordisk. However, there is a lack of data to confirm that semaglutide could be also effective in monogenic obesity.

The hypothesis in this study is that treatment with Semaglutide 2.4mg/week (WEGOVY®) could be as effective in monogenic obesities as in common obesity.

This study is a multicenter study which involves French largest Specialized Obesity Centers (CSO) (among which the APHP coordinating center) All adult patients with a genetic diagnosis of obesity to whom Wegovy is proposed, as part of the WEGOVY® early access and/or commercialization, or for whom Wegovy has already been initiated will be proposed to participate to the study. This also includes any patient having initiated the treatment and already having interrupted it, for any reason.

After the information has been done, the patient or guardian gives to the physician their oral non-opposition for the study that is recorded in the medical records.

This study will take advantage of WEGOVY's pre-marketing, early access authorisation and/or commercialization in France to set up a longitudinal follow-up of patients with monogenic obesity receiving Semaglutide.

Patients already treated with semaglutide at the time of study start (i.e. patients having initiated the treatment in the Early Access programme) will be included and followed-up, whereas inclusion and prospective follow-up of newly treated patients will only begin when Semaglutide becomes officially available.

The aim of the ObGeSema project is to set up a cohort composed of patients (1) having already initiated a treatment and (2) newly treated by Semaglutide in 14 Specialized Obesity Centres (CSOs) and describe their evolution over a 4 year follow-up.

Eligibility Criteria:
Inclusion Criteria:

* Adult Patients (≥18 years)having already initiated a treatment with SEMAGLUTIDE (WEGOVY®) or with a physician's decision to initiate treatment in the standard care in the near future. All patients having initiated a treatment will be proposed to participate, including those having already stopped the treatment at the time of study initiation.
* Confirmation of monogenic obesity, as practiced in clinical routine, by the presence of a pathogenic or likely pathogenic variant in a gene with leptin-melanocortin pathway described in PNDS (https://www.has-sante.fr/jcms/p_3280217/fr/generique-obesites-de-causes-rares)
* Patients duly informed and not objecting to participate in the study
* Patients affiliated to a social security scheme or State Medical Assistance (AME).

Exclusion Criteria:

* Pregnant and breastfeeding women