Active not recruitingPHASE3INTERVENTIONAL

Research Study to Look at How Well the Drug Concizumab Works in Your Body if You Have Haemophilia Without Inhibitors

This research study is testing a new medicine called concizumab for people who have haemophilia A or B. This is for those who do not have 'inhibitors', which are antibodies that can make treatments less effective. The main goals are to find out how well concizumab works to prevent bleeding and to make sure it's safe to use. Some participants who usually treat bleeds as they happen will be randomly assigned to start concizumab straight away or after six months. Others who already take regular medicine to prevent bleeds will start concizumab from the beginning. You'll inject the medicine yourself under the skin every day using a special pen. The study could last up to 8 years, with regular check-ups.

At a glance

Status

Active not recruiting

Phase

PHASE3

Sponsor

Novo Nordisk A/S

Enrolment target

156

Start

13 Nov 2019

Estimated completion

21 Feb 2028

Haemophilia A Without Inhibitors Haemophilia B Without Inhibitors

Results

Results from this study

Posted October 2025

Results have been published for this study.

Primary outcome

Haemophilia A Participants Without Inhibitors: Rate of Treated Spontaneous and Traumatic Bleeding Episodes

Rate of treated spontaneous and traumatic bleeding episodes for haemophilia A participants without inhibitors is presented. The observation period used for reporting this endpoint is on-treatment without ancillary therapy excluding data before restart (OTwoATexBR). It is defined as the time period after the restart where participants are treated by concizumab treatment or are treated by on-demand treatment and additionally have not used factor-containing products not related to treatment of a bleeding episode. The data is reported in the terms of annualised bleeding rate (ABR). Week 0 is defined as time of randomisation to on-demand administration after the pause or time of start of the new concizumab dosing regimen. Confirmatory analyses cut-off was defined as when all participants on no PPX (arm 1) had completed the 24-week visit or withdrawn and all participants on concizumab PPX (in arms 2 and 4) had completed the 32-week visit or withdrawn.

Full results on the registry

What is this study about?

This research is looking into a new medicine called concizumab. It's designed for people who have haemophilia A or haemophilia B. Haemophilia is a condition where your blood doesn't clot properly, leading to longer bleeding. This study specifically welcomes people who don't have something called 'inhibitors', which are a type of antibody some people with haemophilia develop that can stop typical treatments from working well.

The main purpose of this study is to see how effective concizumab is at preventing bleeding. It also wants to make sure the medicine is safe to use. If successful, this new medicine could offer a different way to manage haemophilia for some people.

The study will involve different groups. Some people who only take medicine when they have a bleed will be put into groups by chance – one group will get the new medicine from the start, and the other will continue their usual treatment for six months before trying the new medicine. If you already take regular medicine to prevent bleeds, you would start the new medicine from the beginning of the study.

Key takeaways

This study is for males aged 12 and over with severe haemophilia A or B.
It's looking at a new daily injectable medicine called concizumab to prevent bleeds.
The study is for people who do not have 'inhibitors'.
You'll make daily injections at home using a special pen.
Participation could last up to 8 years with regular check-ups.
You'll record information in a diary and may wear an activity tracker.

Who may be eligible?

To join this study, you need to be male and at least 12 years old. You must have severe haemophilia A or haemophilia B. This means your body produces very little or no factor VIII (for haemophilia A) or factor IX (for haemophilia B) – the proteins needed for blood clotting.

There are also some reasons why you wouldn't be able to join. For example, if you are allergic to any part of the study medicine, or if you have another blood clotting problem that isn't haemophilia. It's also important that you don't have 'inhibitors' (anti-drug antibodies) at the start of the study, as this study is for those without them.

Additionally, if you have a history of blood clots, or are at a high risk of developing them, this study might not be suitable for you. Your study doctor will check all these details carefully to make sure the study is safe for you.

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.

Are you male and at least 12 years old?
Do you have severe haemophilia A or haemophilia B?
Do you *not* have 'inhibitors' (antibodies) in your blood?
Do you have any known allergies to medicines like this?
Have you ever had a blood clot or been told you're at high risk for them?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll be given the study medicine, concizumab, to inject yourself under the skin once a day using a special pen-injector. This can be done at home. Depending on which group you're in, you might start the study medicine right away or after six months. You'll have regular visits with the study doctor – typically every 4 weeks for the first 6 to 12 months, and then every 8 weeks for the rest of the study. If needed, there might be extra visits every 14 weeks. Throughout the study, you'll be asked to record information in an electronic diary, and you might also be asked to wear an activity tracker. The study could last for up to 8 years, or until the medicine becomes available for purchase in your country, or until December 31, 2027.

Potential risks and benefits

By taking part, you might benefit from receiving a new medicine that could help prevent bleeding episodes. However, like all medicines, concizumab may have side effects, and some long-term effects are still being studied. There's also the chance that the medicine might not work as well for you. Your safety is very important, and the study team will monitor you closely for any issues. Remember, you can choose to leave the study at any time, for any reason, without it affecting your usual medical care.

Locations (112)

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

Children's Hospital Los Angeles - Endocrinology
Verified postcode
Los Angeles, United States
Center for Inherited Blood Disorders
Verified postcode
Orange, United States
Center for Blood Disorders Augusta University
Verified postcode
Augusta, United States
Indiana Hemophilia-Thromb Ctr
Verified postcode
Indianapolis, United States
University of Iowa_Iowa City
Verified postcode
Iowa City, United States
Children's Hospital of Michigan
Verified postcode
Detroit, United States
Michigan State University
Verified postcode
Lansing, United States
Novant Hlth Vasc Ins Charlotte
Verified postcode
Charlotte, United States
M.S. Hershey Medical Center
Verified postcode
Hershey, United States
Vanderbilt University Medical Center_Nashville_0
Verified postcode
Nashville, United States
University of Texas San Antonio
Verified postcode
San Antonio, United States
Versiti, CCBD
Verified postcode
Milwaukee, United States

Common questions

What is haemophilia?

Haemophilia is a condition where your blood doesn't clot properly, which means you might bleed for longer after an injury or have internal bleeding more easily.

What are 'inhibitors' in haemophilia?

Inhibitors are a type of antibody that some people with haemophilia can develop, which can stop their usual treatments from working well. This study is for people without these inhibitors.

How will I take the study medicine?

You will inject the medicine yourself under your skin once a day using a pre-filled pen. Your study doctor will show you exactly how to do this.

How long will I be in the study?

The study could last for up to 8 years, but the exact time for you depends on when you join and when the medicine is available in your country, or by December 31, 2027 at the latest.

Will I get the new medicine right away?

If you regularly treat bleeds as they happen, you might start the new medicine right away, or after 6 months. If you already take medicine to prevent bleeds, you will start the new medicine from the beginning.