AuthorisedPhase I and Phase II (Integrated)- First administration to humansInterventional

A study assessing the safety, tolerability, pharmacokinetics and efficacy of single and multiple doses of NNC0638-0355 in participants with overweight or obesity

Carrying excess weight can impact your long-term health and wellbeing. This study looks at an experimental medicine called NNC0638-0355 to find out if it can safely help people manage their weight. Because this is an early-stage trial, it is one of the first times this medicine is being tested in humans. Researchers want to learn about the safety of the medicine, its possible side effects, and how the body handles different doses. Participants will receive either the study medicine or a placebo, which looks identical but contains no active drug. Doctors will measure changes in body weight over 26 weeks and monitor participants' health for up to 32 weeks. Taking part helps scientists discover whether this could become a useful new treatment option in the future.

At a glance

Status

Authorised

Phase

Phase I and Phase II (Integrated)- First administration to humans

Sponsor

Novo Nordisk A/S

Enrolment target

170

Start

14 Sep 2026

Obesity and overweight

What is this study about?

Living with overweight or obesity is very common, but it can increase the risk of developing long-term conditions such as type 2 diabetes, high blood pressure, and joint pain. While healthy eating and regular exercise are vital parts of managing weight, many people find it challenging to reach or maintain a healthier weight through lifestyle changes alone. Because of this, medical researchers are exploring new treatments that work alongside healthy habits.

This trial investigates a new drug called NNC0638-0355. It is an early-phase study, which means doctors are testing the medicine in people for the first time. The main goal is to find out if the drug is well tolerated and safe to use. Researchers also want to see whether taking single or repeated doses can lead to meaningful weight loss over a 26-week period.

During the trial, scientists will track how the body absorbs, breaks down, and removes the medicine over 32 weeks. To ensure the findings are trustworthy, some participants will receive the active study medicine, while others will receive a 'placebo' (a dummy treatment). Comparing the two groups allows researchers to clearly see which effects and benefits come directly from the medicine.

Key takeaways

Tests a new medicine (NNC0638-0355) designed to support weight loss.
Open to adults aged 18 and over who have overweight or obesity.
Compares the study drug against a dummy medicine (placebo).
Tracks changes in body weight over 26 weeks.
Monitors safety and how the body handles the drug for up to 32 weeks.

Who may be eligible?

This trial is designed for adults aged 18 and older who are living with overweight or obesity. Both men and women are welcome to take part.

To be eligible, you will need to meet specific body weight or body mass index (BMI) ranges, which the trial team will measure during an initial screening visit. You must also be able to travel to the study clinic for regular check-ups and health tests.

Certain health issues, recent large changes in weight, or specific medications may mean the trial is not right for you. The study doctors will carefully check your full medical history before you join to ensure it is completely safe for you to take part.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 18 or older.
I have overweight or obesity.
I can travel to a study clinic for regular appointments over several months.
I am willing to have regular blood tests and health checks.
I understand that I might receive a dummy treatment (placebo) instead of the active medicine.

Answer every question to see your result.

What does participation involve?

If you take part, your involvement will last up to around 32 weeks. You will be asked to visit the clinic regularly so the medical team can keep a close eye on your health. During these visits, the team will check your weight, measure your blood pressure, and take blood samples to see how the medicine behaves in your system. You will receive either NNC0638-0355 or a placebo at set times. You may also need to fill in brief questionnaires about your general health and how you feel throughout the trial.

Potential risks and benefits

Taking part may help you lose weight, and you will receive regular, detailed health checks from a specialist medical team. However, because this is an early-stage study, there is a risk of unexpected side effects, and the treatment might not cause you to lose weight. You might also be given the dummy medicine (placebo) instead of the active drug. Taking part is completely voluntary, and you are free to leave the study at any time without your regular NHS care being affected.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
Netherlands

Common questions

What is a placebo?

A placebo is a dummy treatment that looks and feels just like the real medicine but contains no active ingredients. It helps researchers check if the real medicine actually works better than no treatment at all.

How long will I be in the study?

The study monitors your weight and health over 26 to 32 weeks, which includes regular clinic check-ups.

Will I definitely lose weight on this trial?

Weight loss cannot be guaranteed. This is an early test to find out if the medicine works, and there is also a chance you will receive the placebo.

Do I have to pay to take part?

No, clinical trials are free for participants. In most cases, reasonable travel costs to and from the clinic are covered by the trial.

Can I leave the trial if I change my mind?

Yes. Joining is entirely your choice. You can withdraw from the study at any point, and you do not need to give a reason.