An observational study in Obesity (Disorder), Anti-obesity Agents and Precision Medicine, sponsored by National and Kapodistrian University of Athens. Recruiting at 1 site in Greece. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-10.
Sponsored by National and Kapodistrian University of Athens · Observational
Among 103 studies in Obesity with a site in Greece — 31 open to participants now, 38 under way, 16 of them phase 3. Obesity · Greece.
Among the 103 studies in Obesity with a site in Greece, this one is the 9th largest by planned enrollment of the 19 observational ones that give a count, is one of 16 that started in 2026, is one of 19 observational ones, reaches primary completion later than 11 of the 37 other live ones, and was the 93rd registered.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's planned enrollment of 220 is above the median of 114 across 2,154 observational studies indexed under Obesity.
Browse Obesity studies →31 of the 103 studies in Obesity with a site in Greece are open now.
A study can be open while its sites in Greece have not opened yet or have stopped. Only those recruiting at a site in Greece →
Of the 1,336 Obesity studies recruiting now, 377 (28%) set no upper age limit and 856 (64%) stop at 75 or younger; 168 take children under 18; 491 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →103 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 2 6 · Phase 3 30 · Phase 4 6
First in 2004; this study’s year is marked. 16 started in 2026.
Median enrollment 199 across the 84 interventional studies, 207 across the 19 observational. Of the 52 that completed or were terminated, 9 (17%) have results posted.
39 of 103 have an industry lead sponsor. The 10 most frequent:
National and Kapodistrian University of Athens is the lead sponsor of 176 studies on the registry; 54 are open to participants now.
National and Kapodistrian University of Athens has 8 studies filed under Obesity — fewer than ten, so there is no comparison to draw.
9 of the studies in Obesity with a site in Greece that are under way reach primary completion within a year, 4 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06962280Phase 3Eli Lilly and CompanyA Long-Term Study of Tirzepatide (LY3298176) in Adults With Type 1 Diabetes and Obesity or Overweight | 2026-11 |
| NCT07745504Phase 3Novo Nordisk A/SA Research Study to Compare Two Different Versions of Injectable Cagrilintide and Placebo in People With Excess Body Weight | 2027-05-18 |
| NCT06948435Phase 3Eli Lilly and CompanyA Master Protocol Study of Orforglipron (LY3502970) in Participants With Hypertension and Obesity or Overweight (ATTAIN-Hypertension) GZL1 | 2027-09 |
| NCT05556512Phase 3Eli Lilly and CompanyA Study of Tirzepatide (LY3298176) on the Reduction on Morbidity and Mortality in Adults With Obesity | 2027-10 |
| NCT07094568National and Kapodistrian University of AthensTirzepatide vs Liraglutide in Bone | 2026-12-30 |
Among the 103 studies in Obesity with a site in Greece, from their registry updates:
Obesity is a chronic multifactorial disease with a strong genetic component. Although glucagon-like peptide-1 (GLP-1) receptor agonists such as semaglutide and dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonists, such as tirzepatide, are highly effective treatments for obesity, substantial inter-individual variability in weight loss response remains. Genetic factors may contribute to these differences in treatment outcomes.
The aim of this prospective cohort study is to investigate whether a Genetic Risk Score (GRS) and selected obesity-related single nucleotide polymorphisms (SNPs) can predict weight loss response to semaglutide or tirzepatide in adults with obesity. Participants initiating treatment with either medication will undergo clinical, biochemical, and genetic assessment at baseline and will be followed for six months. The study will evaluate the association between genetic markers and treatment response and develop predictive models integrating genetic and clinical variables. The findings may contribute to the development of personalized treatment strategies for obesity.
Obesity is a chronic disease resulting from complex interactions between genetic, environmental, and behavioral factors. Genetic influences account for a substantial proportion of obesity susceptibility, with heritability estimates ranging from 40% to 75%. Genome-wide association studies have identified numerous genetic variants associated with body mass index, appetite regulation, energy homeostasis, and metabolic function.
Glucagon-like peptide-1 (GLP-1) receptor agonists and dual GIP/GLP-1 receptor agonists have significantly improved the pharmacological management of obesity. Semaglutide and tirzepatide produce clinically meaningful weight reduction and improvement in metabolic outcomes. However, treatment response varies considerably among individuals, and the factors underlying this variability are not fully understood.
Genetic Risk Scores (GRS), which combine the effects of multiple obesity-related genetic variants, have emerged as potential tools for predicting disease risk and therapeutic response. Their role in predicting response to anti-obesity pharmacotherapy remains largely unexplored.
This prospective observational cohort study aims to evaluate whether a GRS and selected obesity-related single nucleotide polymorphisms (SNPs) can predict weight loss response to semaglutide or tirzepatide in adults with obesity.
Eligible participants initiating treatment with semaglutide or tirzepatide will be consecutively recruited and followed for six months. At baseline, demographic, clinical, anthropometric, biochemical, and genetic data will be collected. Approximately 18 obesity-related SNPs, including variants in genes involved in appetite regulation, energy balance, and glucose metabolism, will be analyzed. An additive Genetic Risk Score will be calculated based on the cumulative number of risk alleles.
The primary outcome will be percentage weight loss at six months. Participants will subsequently be classified according to treatment response. Associations between genetic markers, GRS categories, and treatment outcomes will be evaluated using multivariable regression models. Receiver operating characteristic (ROC) curve analyses will be performed to assess the predictive performance of genetic and combined genetic-clinical models.
The study is expected to identify genetic predictors of response to GLP-1/GIP receptor agonist therapy and contribute to the development of precision medicine approaches in obesity management. Improved prediction of treatment response may facilitate individualized therapeutic selection, optimize clinical outcomes, and reduce the trial-and-error approach currently used in obesity pharmacotherapy.
Adults with obesity receiving semaglutide or tirzepatide as part of routine clinical care. Participants will undergo clinical, biochemical, and genetic assessment and will be followed prospectively for six months to evaluate the association between genetic risk score, obesity-related genetic variants, and weight loss response.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults with obesity initiating treatment with semaglutide or tirzepatide as part of routine clinical care. Participants are followed prospectively for 6 months to evaluate weight loss response and its association with genetic risk score.
Drug: Semaglutide or Tirzepatide
Adults with obesity initiating treatment with semaglutide or tirzepatide as part of routine clinical care. Participants are followed prospectively for 6 months to evaluate weight loss response and its association with genetic risk score.
This study also gives Semaglutide, Tirzepatide. No intervention listed here names it: that was found by reading the record.
Percentage weight loss at 6 months
Percentage change in body weight from baseline to 6 months following treatment with semaglutide or tirzepatide. The association between weight loss response and genetic risk score (GRS) as well as obesity-related single nucleotide polymorphisms (SNPs) will be evaluated.
Time frame: 6 months
Plan to share: No — Individual participant data (IPD) will not be shared due to privacy considerations, the inclusion of genetic data, and restrictions related to participant consent and data protection regulations.
Started Apr 2026 (actual). Primary completion is estimated for Jan 2027, 9 months after the start.
Of 791 non-industry observational studies under Obesity, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 17 and three quarters within 106. This study's planned 9 months is below that.
Counting every sponsor, half of 836 studies reached it within 39 months; a quarter within 17 and three quarters within 96.
How these figures are worked out, and which studies are left out of them.
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