A study of a once weekly injection under the skin for people with severe hemophilia A (FVIII Activity <1%) or moderately severe to severe B (FIX Activity ≤2%)—with or without inhibitors.

The BASIS study is testing an investigational subcutaneous (under the skin) injection for people with moderately severe to severe hemophilia. The study drug works differently than factor replacement products, as it is a non-factor hemophilia treatment that works in the presence of inhibitors by triggering an alternative clotting mechanism.

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Who may participate

Joining a clinical trial is an important and personal decision. Thank you for considering the BASIS study.

This study may be an option for males aged 12 to 75 who have severe hemophilia A (FVIII Activity <1%) or moderately severe to severe B (FIX Activity ≤2%), with or without inhibitors.

If this study may be a fit for you, you’ll review the details with the study team and ask any questions you have. If you choose to participate, you will sign the informed consent document and continue with screening, to confirm whether you meet the eligibility criteria and are able to participate. The screening period will be up to 45 days, with 1 visit to the study location.


Severe hemophilia A (FVIII Activity <1%) or moderately severe to severe B (FIX Activity ≤2%), with or without inhibitors

The disease, disorder, syndrome, illness, or injury that is being studied. On, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.


12 to 75 years

The age a person must be to participate in a clinical trial.



The sex of people who may participate in a clinical trial. Sex is a person’s classification based on assignment at birth. Eligibility based on sex is distinct from eligibility based on gender.

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What to expect

If you qualify for the study, you will start by taking your current hemophilia treatments for 6 months. You will visit the study location once and have 3 phone calls with the study team during this observational period. The visits and calls are designed check your health status.

Next, you will begin the active study treatment phase in which you’ll take the study drug once a week for 1 year. During this period, you will visit the study location 10 times and have 5 phone calls.

If you complete 12 months of study drug injections, you may be able to participate in a 12 month extension study where you will be able to continue taking the study medicine.  This is an optional extension study.

Length of study treatment

About 21 months

Length of study treatment is the length of time the study participants will receive the study treatment.

Number of study visits

12 visits and 8 phone calls

Each clinical trial’s design specifies the number of study visits and the total length of the trial.

Long-term follow up

1 phone call 1 month after your last dose of study drug

Some studies require the study team to stay in contact with the participant for a period of time after the participant completes the main part of the study. This long-term follow up is to collect additional information on the study drug over time.

About hemophilia

About 60% of people with hemophilia have a severe form of the condition. The severity of hemophilia is determined by measuring the clotting factor activity in a person’s blood. People with severe hemophilia have less than 1% clotting factor activity. By comparison, a person without hemophilia typically has factor activity above 50% and as high as 150%-200%.

The current standard of care treatment for hemophilia is to replace the clotting factor. For some people, the frequency and intravenous (IV) administration of this therapy can make it a burden. For people who have developed inhibitors, the standard replacement therapy is not effective.


About inhibitors

About 15–20% of people with hemophilia develop inhibitors that prevent standard hemophilia treatments from working effectively. The body thinks the replacement clotting factor is a foreign substance and tries to destroy it. People with inhibitors require special treatment, which can be more complicated and expensive than standard treatment.