Active not recruitingPHASE1INTERVENTIONAL

A Study to Investigate Andexanet Dosing and the Interaction Between Andexanet and Subsequent Enoxaparin in Healthy Participants

This research study is looking for healthy volunteers between 18 and 55 years old to test a new medicine called Andexanet. Andexanet is being developed to potentially reverse the effects of certain blood thinning medications like Rivaroxaban and Apixaban, which are used to prevent blood clots. The study has two main goals: first, to understand the best way to give Andexanet, and second, to see how it interacts with another blood-thinning drug called Enoxaparin after Andexanet has been given. By taking part, you would help scientists learn more about how Andexanet works and how it can be used safely in the future to help patients who might need its effects reversed. This is a Phase 1 study, which means it's one of the first steps in testing a new medication in people.

At a glance

Status

Active not recruiting

Phase

PHASE1

Sponsor

AstraZeneca

Enrolment target

179

Start

19 Jan 2026

Estimated completion

11 Jun 2026

Healthy Participants

What is this study about?

This study is exploring a new medicine called Andexanet. Many people take blood thinners, like Rivaroxaban (e.g., Xarelto) or Apixaban (e.g., Eliquis), to prevent serious conditions like strokes or blood clots. These medicines are very important, but sometimes their blood-thinning effect might need to be quickly reversed, for example, if someone has an urgent surgery or a serious bleed. That's where Andexanet comes in; it's designed to quickly stop the blood-thinning action of these medications.

In this study, researchers want to understand two key things. First, they want to figure out the best way to give Andexanet – how much to give and how quickly – to effectively reverse the effects of Rivaroxaban and Apixaban. Second, they are looking at what happens if a person needs to take another type of blood thinner, called Enoxaparin, shortly after receiving Andexanet. This information is really important for doctors to know so they can choose the safest and most effective treatment plans for their patients in various situations.

By taking part, healthy volunteers will help doctors and researchers understand how Andexanet works in the body and how it interacts with other common medications. This kind of early research is crucial for developing new, safe, and effective treatments that can ultimately benefit many patients in the future.

Key takeaways

This study is testing a new medicine called Andexanet in healthy volunteers.
It aims to understand how Andexanet works with common blood thinners and if it affects Enoxaparin.
Participation involves an initial screening, a 5-day stay at a study centre, and follow-up visits.
You will receive either Andexanet, a blood thinner, or a placebo.
Your involvement helps gather important information for future patient care.
You can withdraw from the study at any time.

Who may be eligible?

To join this study, you need to be a healthy adult between 18 and 55 years old. Your Body Mass Index (BMI) should be between 18.5 and 30, and you should weigh at least 60 kg. Women who can have children will need a negative pregnancy test and must use highly effective contraception throughout the study. Men with female partners who can have children also need to use specific contraception methods.

There are several reasons why you might not be able to join. For example, if you have a history of any major health problems, especially those affecting your stomach, liver, kidneys, or if you have any bleeding disorders. You also can't participate if you've had issues like blood clots or conditions that increase your risk of clotting. Taking certain medicines or having conditions like asthma or lung disease might also make you ineligible. The research team will review your full medical history to make sure taking part is safe for you.

Quick self-check

Are you between 18 and 55 years old?
Do you have a Body Mass Index (BMI) between 18.5 and 30?
Do you weigh at least 60 kg?
Are you generally healthy with no significant chronic medical conditions?
Are you willing to avoid alcohol, smoking, and recreational drugs during the residential stay?
If female, are you willing to use effective contraception if you could become pregnant?

This is a guide only — the research team will confirm whether you can take part.

What does participation involve?

If you decide to take part, you'll first have a screening visit that could last up to 28 days to make sure you're suitable for the study. After that, you'll stay at the study centre for approximately 5 days. During this time, you will receive either Andexanet, a blood thinner (Rivaroxaban, Apixaban, or Enoxaparin), or a placebo (a dummy treatment). The specific medication you receive depends on the study group you are assigned to. You'll have regular blood tests and other checks to see how your body reacts to the medication.

After your stay at the centre, there will be a safety follow-up period for about 3 days. Finally, you'll have one last follow-up visit about 30 days (give or take 7 days) after you received your last study medication or placebo. Throughout the study, you'll need to avoid alcohol, smoking, and recreational drugs during your residential stay.

Potential risks and benefits

Taking part in any medical study has potential benefits and risks. You won't directly benefit from this study, as it's designed to gather information for future patients. However, you will be contributing to valuable medical research that could help others. Potential risks include discomfort from blood tests or injections, and possible side effects from the study medications, which will be carefully monitored by the medical team. You will be told about any known side effects before you agree to take part. It's important to remember that you are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (2)

Research Site
Berlin, Germany
Research Site
Harrow, United Kingdom

Common questions

What is Andexanet?

Andexanet is an investigational medicine designed to quickly reverse the effects of certain commonly used blood thinning medications if necessary.

Why are healthy people needed for this study?

To understand how a new medicine works in the body without the complications of existing health conditions, researchers often first test it in healthy volunteers.

Will I receive a blood thinner as part of the study?

Yes, depending on your assigned group, you may receive Rivaroxaban, Apixaban, or Enoxaparin, in addition to Andexanet or a placebo.

How long will I need to stay at the study centre?

You will stay at the study centre for approximately 5 days, preceded by a screening period and followed by further check-ups.

Can I leave the study at any point?

Yes, you have the right to withdraw from the study at any time, for any reason, without it affecting your future medical care.