Skip to content
Clinical Trials – home
Not yet recruiting

A study of NNC0638-0355 to evaluate safety, tolerability and weight loss with multiple doses in adults with obesity or overweight

Verified siteInvestigational
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

The study focuses on people who have obesity or are classified as overweight. These conditions mean a person has more body weight than is considered healthy, which can increase the risk of health problems. The medication being tested is a new oral tablet called NNC0638-0355. It is being compared with a dummy tablet, known as placebo, to see how it works.

The main goal of the research is to see whether taking several doses of the new medicine leads to a greater reduction in body weight over about six months compared with the dummy tablet. Participants will first have a screening visit, then begin taking the assigned tablets once daily for up to 26 weeks, with regular check‑ins to monitor safety and how the drug is processed in the body. Throughout the study, weight will be measured at the start and at the end to determine any change.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline assessment (week 0)

    On the first day after joining the study you will attend a baseline visit. during this visit your body weight will be measured, a brief medical check will be done, and blood will be drawn to assess your health status.

    The study staff will assign you to receive either nnc0638-0355 tablets or matching placebo tablets. this process is called randomization and it ensures that the assignment is made by chance.

  2. Step 2

    First dose administration

    On the same day as the baseline visit you will take a single tablet. the tablet may be one of the nnc0638-0355 test tablets (identified as product a or b) or a matching placebo tablet (identified as placebo a or b). the tablet is taken by mouth.

    The exact amount of the tablet is defined by the study protocol; the label does not specify a numerical dose.

  3. Step 3

    Multiple‑dose period (weeks 1–26)

    After the first dose you will continue to take one tablet each day for up to 26 weeks. the tablet you receive will remain the same type (either nnc0638-0355 or placebo) throughout this period.

    You will be instructed to take the tablet at the same time each day and to record each dose in the study diary provided.

  4. Step 4

    Regular follow‑up visits

    Throughout the 26‑week period you will attend scheduled visits. at each visit your body weight will be measured again, and additional safety checks will be performed.

    Blood samples will be collected at several visits to measure the amount of nnc0638-0355 in your bloodstream. these measurements help determine how the medicine is processed by the body.

  5. Step 5

    Final assessment (week 26)

    At the end of week 26 you will have a final visit. the primary outcome of the study is the relative change in your body weight from the baseline measurement to this final measurement.

    A final set of blood samples will be taken to complete the pharmacokinetic evaluation, and any remaining study tablets will be returned.

Who can join the trial?

3 criteria

  • Be between 18 and 64 years old when you sign the consent form.
  • Have a body mass index (BMI) of 27.0 to 39.9 kg/m², which means your weight compared to your height is in the overweight or obese range, and the extra weight must be due to excess body fat (adipose tissue).
  • Be judged by the study doctor to be generally healthy based on your medical history, a physical exam, and the results of basic health checks such as vital signs (blood pressure, heart rate, temperature), an electrocardiogram (ECG) (a test that records the heart’s electrical activity), and routine clinical laboratory tests (blood and urine tests).

Who cannot join the trial?

4 criteria

  • Having a known or suspected hypersensitivity (allergic reaction) to the study drug or any similar products.
  • Having any other health problem that the doctor believes could make the study unsafe for you or make it difficult for you to follow the study rules.
  • Having a blood test result called HbA1c that is 6.5% or higher (this test shows average blood sugar over several months and a level of 6.5% or more indicates diabetes).
  • Having abnormal levels of vitamin D, parathyroid hormone (PTH), or total calcium in the blood, as judged to be important by the study doctor.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not yet recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • NNC0638-0355 A 10219

    is an experimental tablet that contains the investigational compound NNC0638-0355. In this study the tablet is taken by mouth and is being tested to see if it can safely help people who are overweight or have obesity lose weight over several weeks. Researchers will look at how the body absorbs the drug, any side effects, and how much weight participants lose compared with a placebo.

  • NNC0638-0355 B 10216

    is another form of the same experimental tablet containing the compound NNC0638-0355. It is also taken orally and is evaluated for safety, how the drug moves through the body, and its ability to reduce body weight when given repeatedly over time.

  • NNC0638-0355 B 10215

    is a tablet version of the investigational drug NNC0638-0355. Participants swallow this tablet, and the study monitors its tolerability, the pattern of drug levels in the blood, and the change in body weight compared with a placebo group.

  • NNC0638-0355 A 10218

    is an oral tablet that includes the experimental substance NNC0638-0355. The trial uses this tablet to assess whether regular dosing is safe and whether it helps participants lose weight, while also measuring how the drug is processed by the body.

  • NNC0638-0355 A 10217

    is a tablet form of the investigational compound NNC0638-0355 taken by mouth. The study examines its safety, how it is absorbed and cleared, and its effectiveness in producing weight loss in people with overweight or obesity.

What is already known about the treatment

  • NNC0638-0355

    This investigational drug is taken as an oral tablet, swallowed with water. It is currently in clinical testing and has not yet been approved for regular medical use. The medication is being studied for the treatment of overweight and obesity by helping to lower body weight. It works by influencing brain signals that control appetite, and it is classified as a novel anti‑obesity small‑molecule agent.

  • Placebo A

    This is an inactive tablet that contains no active drug ingredients and is given by mouth in the same way as the test medication. It is used only in clinical trials to serve as a control for comparing the effects of the active drug. The placebo has no therapeutic purpose and does not affect body weight. It is classified simply as a placebo, an inert substance used in research.

  • Placebo B

    Like Placebo A, this product is an inert tablet taken orally and contains no active medication. It is included in the study to provide a comparison group for the investigational drug. The tablet does not have any medical effect and is categorized as a placebo used in clinical research.

Investigated diseases

  • Obesity

    A condition in which excess body fat accumulates to the point that it may affect health. It is usually defined by a body‑mass index (BMI) of 30 kg/m² or higher. Over time, the excess weight can increase gradually, often driven by an imbalance between calorie intake and energy expenditure. As the amount of fat grows, it can lead to changes in metabolism and hormone levels. The condition tends to persist unless lifestyle, environmental, or biological factors shift.

  • Overweight

    A state where body weight is higher than what is considered normal for a given height, typically indicated by a BMI between 25 and 29.9 kg/m². It reflects a modest excess of body fat that may develop slowly over months or years. Without changes in diet, activity, or other influences, the extra weight can remain stable or slowly increase. It may be a stepping stone toward higher levels of body fat. The condition can persist as long as the underlying energy balance remains positive.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2026-526797-16-00Protocol codeNN9638-7569Estimated enrolment380 patientsSponsorNovo Nordisk A/S

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.