A Phase III study of NXT007 compared with simoctocog alfa prophylaxis in patients with Hemophilia A without inhibitors

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What is this study about?

Hemophilia A is a rare bleeding disorder in which the blood lacks enough of a clotting protein called factor VIII, making it difficult for blood to stop bleeding after an injury. In people without inhibitors (antibodies that block treatment), regular preventive treatment, known as prophylaxis, is used to lower the risk of bleeding episodes. This study compares a new medicine called NXT007, a humanised IgG4 monoclonal antibody that links two clotting proteins (FIXa and FX) and is given by subcutaneous injection (an injection under the skin), with standard prophylaxis using Factor VIII that is administered intravenously (through a vein). Both approaches aim to reduce the number of bleeds.

The purpose of the study is to evaluate whether the new medicine can lower the number of treated bleeds compared with standard therapy. Participants will be assigned to receive either the new medicine or the standard factor VIII for about six months, attending regular visits where any bleeding events are recorded, quality‑of‑life questionnaires are completed, and safety checks such as blood tests for antibodies or reactions at the injection site are performed. The trial will monitor how often injections are needed, the amount of medicine used, and any side effects that arise during the treatment period.

1 enrollment and consent

upon joining the study, you sign a consent form that explains the purpose of the trial and the procedures you will follow.

the study team records your basic health information and confirms that you have hemophilia a without inhibitors.

2 randomization to treatment group

after enrollment, you are randomly assigned to receive either nxt007 or factor viii prophylaxis.

the assignment is made by a computer system and you will not know the reason for the specific group.

3 baseline assessments

before the first dose, you undergo a series of assessments that include blood tests, a physical examination, and questionnaires about your quality of life.

these measurements serve as a reference point for later comparisons.

4 first dose of assigned medication

you receive the initial dose of the medication assigned to you.

nxt007 is a humanised igg4 monoclonal antibody that targets the proteins fixa and fx; it is given as a subcutaneous injection (under the skin).

factor viii (simoctocog alfa) is a clotting factor; it is given by intravenous administration (through a vein).

the exact dose and the amount of medication are determined by the study physicians based on your body weight and clinical guidelines.

5 regular prophylactic injections

for the next six months, you continue to receive the assigned medication on a regular schedule.

the frequency (for example, weekly or twice weekly) is set by the study protocol and explained to you by the study staff.

each injection is administered either at the clinic or, if approved, at home following written instructions.

the purpose of these regular doses is to prevent bleeding episodes, which is called prophylaxis.

6 clinic visits and monitoring

throughout the six‑month treatment period you attend scheduled clinic visits, typically every month or as specified by the protocol.

at each visit you report any bleeds that occurred, undergo blood sampling to measure drug levels, and answer quality‑of‑life questionnaires.

the study team records any adverse events, such as reactions at the injection site or other side effects.

7 safety and laboratory evaluations

regular laboratory tests are performed to monitor your blood clotting ability, liver function, and the presence of antibodies that might reduce the effectiveness of the study drug.

any serious or unexpected side effects are evaluated immediately, and the study medication may be stopped if required for safety.

8 month‑7 final assessment

at the end of the six‑month treatment phase you attend a final visit, usually scheduled at month 7.

this visit includes a repeat of the quality‑of‑life questionnaire, a physical examination, and blood tests to assess the final drug concentration and any antibodies formed.

the data collected at this visit are used to compare the effectiveness of nxt007 versus factor viii.

9 study completion

after the month‑7 visit, the active part of the study ends for you.

the study team will thank you for your participation and may provide information about any follow‑up that is recommended.

Who Can Join the Study?

Have a confirmed diagnosis of severe (factor VIII activity less than 1 IU/dL) or moderate (factor VIII activity between 1 and 5 IU/dL) congenital Hemophilia A without any inhibitors against factor VIII.
No inhibitor has been recorded in the past three years, meaning the inhibitor level is below 0.6 Bethesda Units per milliliter (BU/mL).
The half‑life of factor VIII (the time it stays active in the blood) must be at least 6 hours, and the recovery after a dose must be greater than 66% in the last three years.
A negative inhibitor test (under 0.6 BU/mL) must have been documented within the 12 months before enrollment.
You must have written details of both regular (preventive, called prophylactic) and on‑demand (called episodic) factor VIII treatment, as well as a list of bleeding episodes for at least the six months before screening.
You must agree to follow the study’s contraception requirements if you could become pregnant.
Both men and women are eligible to participate, including children and adults.

Who Cannot Join the Study?

Allergy to any study medication, its ingredients, or any drug allergy that the doctor believes makes participation unsafe.
Use of medicines that affect the whole immune system (called systemic immunomodulators) such as interferon or rituximab now or planned during the study, except for HIV medicines (anti‑retroviral therapy).
Planned surgery during the study period, except for very minor procedures like a simple tooth extraction or draining an abscess.
Having an abnormal heart test (ECG – a test that records the heart’s electrical activity) that is considered serious, such as a complete left bundle branch block, second‑ or third‑degree heart block, or a past heart attack (myocardial infarction).
Refusing to receive plasma‑derived or blood product transfusions if an emergency occurs.
History of dangerous heart rhythm problems (ventricular dysrhythmias) or risk factors for them, such as serious heart muscle disease (e.g., severe left ventricular systolic dysfunction or thickened heart wall called left ventricular hypertrophy) or coronary heart disease that causes symptoms or shows reduced blood flow on tests.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country	Status
Medical University Of Vienna	Vienna	Austria

Other Sites

Site Name	City	Country	Status
Rigshospitalet	Copenhagen	Denmark

Trial status

Country	Status	Recruitment Start
Austria	Not yet recruiting	30.06.2026
Denmark	Not yet recruiting	30.06.2026

Trial locations

Investigated drugs:

COAGULATION FACTOR VIII is a protein that helps blood clot normally. In this study it is used as the standard treatment (comparator) for people with hemophilia A who do not have inhibitors. It is given by intravenous injection and works by replacing the missing clotting factor that people with hemophilia A lack, helping to prevent bleeding episodes.

NXT007 is a new, lab‑engineered antibody designed to act like clotting factor VIII. It is a humanised IgG4 monoclonal antibody that binds to two other clotting proteins (FIXa and FX) and brings them together, allowing the blood‑clotting process to occur. In the trial it is tested as a subcutaneous injection (under the skin) and is being evaluated as an alternative prophylactic therapy to reduce bleeding in people with hemophilia A without inhibitors.

Hemophilia A Without Inhibitors – Hemophilia A is a genetic bleeding disorder caused by low levels of clotting factor VIII, which makes it hard for blood to form a stable clot. People with this form do not develop antibodies that neutralize factor VIII, so their bleeding pattern follows the typical course of the disease. They often notice easy bruising, nosebleeds, and bleeding into joints. The condition is present from birth and can worsen as repeated joint bleeds lead to pain and stiffness. Bleeding episodes may occur spontaneously or after minor injuries. Over time, untreated joint bleeds can lead to progressive joint damage.

Trial ID:

2025-522434-32-00

Protocol code:

WO45886

Trial Phase:

Therapeutic confirmatory (Phase III)

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A Phase III study of NXT007 compared with simoctocog alfa prophylaxis in patients with Hemophilia A without inhibitors

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?