A Phase 2 interventional study of Atomoxetine and Placebo in Melanocortin Obesity Syndrome and MCOS, sponsored by Icahn School of Medicine at Mount Sinai. Recruiting at 3 sites in United States. Open to participants aged 6 Years and older. Per ClinicalTrials.gov, last updated 2026-08-07.
Sponsored by Icahn School of Medicine at Mount Sinai · Phase 2, Interventional, and Treatment
Among 15 studies in Obesity by Icahn School of Medicine at Mount Sinai — 3 open to participants now, 3 under way, none of them phase 3. Obesity · Icahn School of Medicine at Mount Sinai.
Among the 15 studies in Obesity by Icahn School of Medicine at Mount Sinai, this one is the 10th largest by planned enrollment of the 13 interventional ones that give a count, is the only one that started in 2026, is one of 2 in phase 2, and was the 14th registered.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
Browse Obesity studies →3 of the 15 studies in Obesity by Icahn School of Medicine at Mount Sinai are open now, in 1 country. Recruiting first, the newest first:
Icahn School of Medicine at Mount Sinai · Sites in United States
Icahn School of Medicine at Mount Sinai · Sites in United States
By country, each count listing its studies:
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: 6 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
15 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 1 · Phase 2 3 · Phase 3 1 · Phase 4 1
First in 2008; this study’s year is marked. 1 started in 2026.
This study's planned enrollment of 20 is below the median of 67 across 9,006 interventional studies indexed under Obesity.
Median enrollment 28 across the 13 interventional studies, 7,392 across the 2 observational. Of the 10 that completed or were terminated, 5 (50%) have results posted.
This tab as a report to print or save as PDF → With an account.
Icahn School of Medicine at Mount Sinai is the lead sponsor of 776 studies on the registry; 176 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 83 (66%) have results posted.
1 of the studies in Obesity by Icahn School of Medicine at Mount Sinai that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07310875Icahn School of Medicine at Mount SinaiGastric Ultrasound in Patients Who Have Undergone Bariatric Surgery | 2026-12-30 |
Among the 15 studies in Obesity by Icahn School of Medicine at Mount Sinai, from their registry updates:
Nothing recorded among them since 2026-09-25.
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This is a phase 2 randomized placebo-controlled crossover trial to determine the safety and efficacy of atomoxetine for treating obesity caused by loss-of-function variants in the melanocortin-4 receptor (MC4R), the most common cause of genetic obesity disorders. Atomoxetine was selected for this pilot trial because it has been shown to increase brain-derived neurotrophic factor (BDNF) within the central nervous system and in peripheral circulation. Targeting BDNF is a specific strategy for treating MC4R abnormalities because BDNF functions as a downstream mediator of MC4R signaling.
Targeted therapies for the treatment of monogenetic obesity are essential because typical lifestyle interventions and standard anti-obesity medications are largely ineffective as they do not correct the specific genetic defect causing abnormal energy balance. The leptin pathway is the key regulator of body weight through control of appetite and energy expenditure. In particular, the severe insatiable hunger experienced by patients with leptin pathway disorders leads not only to extreme obesity, but the unrelenting drive to seek food also causes substantial distress for patients and caregivers. While therapies have been developed for treating genetic disorders affecting the proximal portion of the leptin pathway (LEP, LEPR, POMC, PCSK1, and BBS1-22), there are no treatments for loss-of-function LOF) variants of the melanocortin-4 receptor gene (MC4R), which cause melanocortin obesity syndrome (MCOS). In various population and cohort studies, 1-6% of patients with severe, early onset obesity are found to have MC4R LOF variants, making MCOS the most common cause of genetic obesity. Brain-derived neurotrophic factor (BDNF) is a downstream mediator of MC4R signaling and, therefore, may serve as a specific target for MCOS treatment. The researchers propose repurposing a well-understood and commercially available attention-deficit hyperactive disorder (ADHD) medication, atomoxetine (FDA-approved for the treatment of ADHD in persons ages 6 years and older), for the treatment of MCOS because of animal and human studies show that this drug induces endogenous BDNF levels. Atomoxetine could potentially increase hypothalamic BDNF levels, leading to weight loss through improved anorectic signaling downstream of the abnormally functioning MC4R. A phase 2 randomized, placebo-controlled crossover trial in 20 patients with MCOS will be conducted to test this hypothesis. The study will begin in adult patients and if safety and efficacy are shown, then pediatric patients age ≥ 6 years will be studied. The primary outcome measure will be change in BMI (expressed as the percentage of the 95th percentile BMI for age/sex). Additional measures will include percent body fat and visceral fat area by bioelectrical impedance analysis, resting energy expenditure by indirect calorimetry, dietary intake by food frequency questionnaire and 24-hour recall, hyperphagia score, hunger level, satiety level, hemoglobin A1c, lipid panel, liver function tests, blood pressure, heart rate, and ADHD symptoms. Serum and plasma BDNF and genetic variants in atomoxetine metabolism enzymes will be assessed and correlated with weight changes. This pilot clinical trial will provide valuable data on the safety and efficacy of atomoxetine for treating MCOS, and the data will be used to guide the design of a future phase 3, multicenter, randomized clinical trial.
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive placebo for 16 weeks (4 weeks titration + 12 weeks at target dose), followed by washout period, then atomoxetine for 16 weeks (4 weeks titration + 12 weeks at target dose).
Drug: Atomoxetine · Drug: Placebo
Participants receive atomoxetine for 16 weeks (4 weeks titration + 12 weeks at target dose), followed by washout period, then placebo for 16 weeks (4 weeks titration + 12 weeks at target dose).
Drug: Atomoxetine · Drug: Placebo
Initial dose 40 mg, day 7 dose 60 mg, day 14 dose 80 mg, day 21 dose 100 mg (target dose)
Matching placebo oral capsule
Body Mass Index (BMI)
BMI will be calculated as kg/sq m. The sex appropriate CDC growth chart will be used to calculate BMI as a percent of the 95th percentile (BMI95). For patients \>20 years, the 20-year-old percentiles will be used.
Time frame: 16 weeks
Resting Energy Expenditure (REE)
Resting energy expenditure (REE) will be measured by indirect calorimetry after a minimum 1 hour of rest in the Clinical Research Center. Oxygen consumption and carbon dioxide production will be measured. The first 5-10 minutes of data will be discarded to allow participants to adjust to the metabolic cart.
Time frame: 16 weeks
Healthy Eating Index (HEI)
The VioScreen assessment provides a Healthy Eating Index (HEI) score to measure the quality of a person's diet. The HEI score ranges from 0 to 100, with higher scores indicating better eating habits.
Time frame: 16 weeks
Hyperphagia Questionnaire (HQ)
Hyperphagia will be assessed with the Hyperphagia Questionnaire (HQ) This is a 13-item questionnaire with each question answered on a 5-point scale. Two of the questions are qualitative. Full range is scored from 11 to 55. Higher score indicates greater hyperphagia.
Time frame: 16 weeks
Hunger and Satiety Score
Full range scored from 0 to 10 with higher score indicating greater hunger/satiety.
Time frame: 16 weeks
Fasting Glucose Level
A blood sugar test measures the amount of a sugar called glucose in a sample of blood. Fasting laboratory studies will be obtained at week 0, week 16 and week 32.
Time frame: At week 0, week 16 and week 32.
Alanine Transaminase (ALT) Level
The alanine transaminase (ALT) blood test measures the level of the enzyme ALT in the blood. ALT is an enzyme found in a high level in the liver. An enzyme is a protein that causes a specific chemical change in the body. Fasting laboratory studies will be obtained at week 0, week 16 and week 32.
Time frame: At week 0, week 16 and week 32.
Fasting Insulin Level
The insulin level in blood. Insulin is a hormone produced by beta cells in the pancreas. Fasting laboratory studies will be obtained at week 0, week 16 and week 32.
Time frame: At week 0, week 16 and week 32.
Hemoglobin A1c
A1C is a lab test that shows the average level of blood sugar (glucose) over the previous 3 months. It shows how well blood sugar is controlled to help prevent complications from diabetes. Fasting laboratory studies will be obtained at week 0, week 16 and week 32.
Time frame: At week 0, week 16 and week 32.
Lipid Panel - Fasting LDL, HDL, Triglycerides
A lipid profile is a blood test to measure different types of lipids: High-density lipoprotein cholesterol (HDL \[good\] cholesterol): HDL helps remove LDL from your blood. Low-density lipoprotein cholesterol (LDL \[bad\] cholesterol): LDL can build up in your blood vessels and increase your heart disease risk. Triglycerides: Your body makes some triglycerides. Triglycerides also come from the food you eat. Extra calories are turned into triglycerides and stored in fat cells for later use. Fasting laboratory studies will be obtained at week 0, week 16 and week 32.
Time frame: At week 0, week 16 and week 32.
High Sensitivity C-Reactive Protein
C-reactive protein (CRP) is produced by the liver. The level of CRP rises when there is inflammation in the body. It is one of a group of proteins, called acute phase reactants that go up in response to inflammation. The levels of acute phase reactants increase in response to certain inflammatory proteins called cytokines. These proteins are produced by white blood cells during inflammation. The CRP test is a general test to check for inflammation in the body. It is not a specific test. A high-sensitivity C-reactive protein (hs-CRP) is a more A more sensitive CRP test Fasting laboratory studies will be obtained at week 0, week 16 and week 32.
Time frame: At week 0, week 16 and week 32.
The ASEBA Brief Problem Monitor
The ASEBA Brief Problem Monitor (BPM) is a quick assessment tool designed to monitor and track a child's behavioral and emotional problems over time, particularly focusing on internalizing, externalizing, and attention issues. Range is 0 to 99.9th percentile
Time frame: 16 weeks
Adult ADHD Self-Report Scale (ASRS-v1.1) Symptom Checklist.
This is an 18-item self-report questionnaire designed for individuals to assess their own symptoms of Attention Deficit Hyperactivity Disorder (ADHD) focusing on daily experiences related to attention, impulsivity, and hyperactivity. Total scale is scored 0-72 with higher score indicating more predictive of an ADHD diagnosis.
Time frame: 16 weeks
Plan to share: Yes — Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices).
Supporting information: Study protocol
Time frame: Beginning 9 months and ending 36 months following article publication.
Access criteria: Researchers who provide a methodologically sound proposal. To achieve aims in the approved proposal. Proposals may be submitted up to 36 months following article publication. After 36 months the data will be available in our University's data warehouse but without investigator support other than deposited metadata. Information regarding submitting proposals and accessing data may be found at (Link to be included in the URL field below).
Data sharing details ↗ · dataverse.org
No publications or documents are linked to this record.
Start is estimated for Sep 2026; primary completion for Mar 2028, 18 months later.
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 18 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.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Studies of the drug tested here: Atomoxetine
Icahn School of Medicine at Mount Sinai →