A Phase 2 interventional study of ATR-258 in Overweight and Obesity, sponsored by Morten Hostrup, PhD. Active, not recruiting at 1 site in Denmark. Open to male participants aged 21 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-14.
Sponsored by Morten Hostrup, PhD · Phase 2, Interventional, and Basic science
Among 350 studies in Obesity with a site in Denmark — 58 open to participants now, 84 under way, 23 of them phase 3. Obesity · Denmark.
Among the 350 studies in Obesity with a site in Denmark, this one is the 263rd largest by enrollment of the 282 interventional ones that give a count, is one of 26 that started in 2026, is one of 20 in phase 2, reaches primary completion later than 35 of the 83 other live ones, and was the 328th registered.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
Browse Obesity studies →58 of the 350 studies in Obesity with a site in Denmark are open now. Recruiting first, the newest first:
University Hospital, Gentofte, Copenhagen · Sites in Denmark
University of Copenhagen · Sites in Denmark
Signe Torekov · Sites in Denmark
AstraZeneca · Sites in Denmark, United States, Argentina and 8 more countries
Novo Nordisk A/S · Sites in Denmark, United States, Belgium and 7 more countries
A study can be open while its sites in Denmark have not opened yet or have stopped. Only those recruiting at a site in Denmark →
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: 21 Years to 45 Years · male · healthy volunteers too.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
350 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 1 15 · Phase 2 25 · Phase 3 42 · Phase 4 18
First in 1983; this study’s year is marked. 26 started in 2026.
This study's enrollment of 13 is below the median of 67 across 9,006 interventional studies indexed under Obesity.
Median enrollment 74 across the 282 interventional studies, 93 across the 68 observational. Of the 233 that completed or were terminated, 14 (6%) have results posted.
This tab as a report to print or save as PDF → With an account.
65 of 350 have an industry lead sponsor. The 10 most frequent:
Morten Hostrup, PhD is the lead sponsor of 17 studies on the registry; 7 are open to participants now.
Morten Hostrup, PhD has 1 study filed under Obesity — fewer than ten, so there is no comparison to draw.
14 of the studies in Obesity with a site in Denmark that are under way reach primary completion within a year, 2 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06914895Phase 3Eli Lilly and CompanyA Study of Tirzepatide (LY3298176) Compared With Placebo in Adults With Type 1 Diabetes and Obesity or Overweight | 2026-11 |
| NCT06858839Phase 3AmgenEvaluation of Maridebart Cafraglutide in Adult Participants Without Type 2 Diabetes Mellitus Who Have Obesity or Are Overweight | 2027-01-21 |
| NCT06833749KeyBioscience AGEfficacy and Safety of KBP-336 in Obese Individuals with Osteoarthritis | 2026-11 |
| NCT07463495University of AarhusThe Metabolic Effects of Oral Tributyrin Administration | 2026-12 |
| NCT06624462Bjorn H. EbdrupEffectiveness of a Pragmatic, Metabolic Care Clinic for Patients With Severe Mental Illness - The Meta Care Clinic | 2026-12 |
Among the 350 studies in Obesity with a site in Denmark, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This longitudinal mechanistic physiological study examines biased β2-adrenergic receptor (β2-AR) signaling in human skeletal muscle, with emphasis on G protein-coupled receptor kinase (GRK)-mediated pathways. Participants will receive daily oral dosing of the GRK-selective long-acting β2-agonist ATR-258 for 8 weeks. Muscle biopsies and physiological measurements will quantify GRK-, cAMP/PKA-, and β-arrestin-related up- and downstream signaling, fiber-type specificity, and potential receptor desensitization with repeated stimulation along with functional read-outs, tissue distribution, cardiovascular response and tolerability.
Healthy men with overweight/obesity will complete an 8-week intervention with daily oral ATR-258 (0.5-2.5 mg/day). On experimental days (Days 1, 15, 29, and 56), β2-AR signaling sensitivity will be assessed before and after stimulation (1-2, 4, and 8 hours) using blood biomarkers, hemodynamics, indirect calorimetry, and lower extremity muscle function/power testing. Muscle biopsies (vastus lateralis) will be obtained at rest and 4 hours after stimulation on Days 1, 29, and 56 to quantify downstream signaling (GRK, cAMP/PKA, β-arrestin), phosphorylation of rpS6/mTOR/Akt, β2-AR content, and muscle fiber morphology.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's enrollment of 13 is below the median of 67 across 9,006 interventional studies indexed under Obesity.
Browse Obesity studies →Morten Hostrup, PhD is the lead sponsor of 17 studies on the registry; 7 are open to participants now.
Compared within Obesity, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Overweight. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Daily oral ATR-258
Drug: ATR-258
Daily oral ATR-258 for 8 weeks with repeated experimental assessment days (Days 1, 15, 29, 56).
Intensity of β2-AR downstream signaling pathways (e.g. GRK, cAMP/PKA, β-arrestin, rpS6) in type I and type II muscle fibers
Assessed in vastus lateralis biopsies at rest
Time frame: Before and 4 hours after ATR-258 ingestion on day 1, 29, and 56.
Phosphorylation of rpS6, mTOR, and Akt in type I and type II muscle fibers
In response to ATR-258 ingestion
Time frame: Day 1, 29 and, 56.
Lean/fat mass
Measured by DXA scan
Time frame: Day 1, 15, 29, and 56
Muscle function
Participants will perform lower extremity peak exercise and a one-legged knee-extensor exercise protocol to exhaustion before and after the full intervention to assess muscle power and endurance
Time frame: Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
Peripheral glucose clearance including OGTT-derived outcomes
Time frame: Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
β2-adrenergic receptor content in type I and type II muscle fibers
Measured by western blotting
Time frame: On day 1, 29 and 56
Resting metabolic rate (incl. carbohydrate and fat oxidation)
Measured by indirect calorimetry
Time frame: Before and 1, 2, 4 and 8 hours after ATR-258 ingestion on day 1, 15, 29, and 56.
Femoral arterial blood flow
Measured by Doppler.
Time frame: Before and 1, 2, 4 and 8 hours after ATR-258 ingestion on day 1, 15, 29, and 56.
Continous ECG and heart rate
Participants will wear a Holter-device for 4 x 5 days to continuously measure ECG and heart rate. The periods will be after the screening (baseline period), and after trial days on Day 1, 15, and 29.
Time frame: A 5-day baseline period, and day 1-5, day 15-20, and day 29-34 of ATR-258 administration.
Muscle fiber cross-sectional area (type I and type II)
Measured by histochemical analysis
Time frame: Day 1, 29, and 56
Maximal electrically-stimulated muscle force development and relaxation
Isometric quadriceps. Measured seated with leg in 90 degree angle and attached to strain gauge.
Time frame: Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
Plan to share: No
No publications or documents are linked to this record.
Started Feb 2026 (actual). Primary completion is estimated for Dec 2026, 10 months after the start.
Of 132 non-industry phase 2 interventional studies under Obesity, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 57. This study's planned 10 months is below that.
Counting every sponsor, half of 308 studies reached it within 16 months; a quarter within 10 and three quarters within 35.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: ATR-258
Morten Hostrup, PhD